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3.4 L32 V6/60... questions... compared to L44 by 82-T/A [At Work]
Started on: 05-10-2023 02:47 PM
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Last post by: pmbrunelle on 05-25-2023 06:58 PM
82-T/A [At Work]
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Report this Post05-10-2023 02:47 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
Ok, so I'm starting to re-think my own choices. I have a 3.2 that I've rebuilt, and thinking that rather than mess with that original engine, I could simply just go with a long block 3.4 (93 Firebird) that comes with a 4-year warranty that's been tested, and just build off of that.

So when looking at the power output, the Fiero engine puts out 140hp at 5,200 rpms; however, the L32 puts out 160hp at 4,600 rpms.

I realize the L32 is going to simply be quicker, just because it's more powerful, but what is the cause for the peak power to be at lower RPMs, and should I care? Back in the day, I've always enjoyed winding out the gears in my Fiero when it was a 2.8, and I always felt like it built power well into the 5,000+ rpm range. I would hate to think that all the power for the L32 (Firebird motor) is all in the low and mid-range? From what I understand, the cams are identical between the Fiero and the grind that's on the L32.

Aside from the fact that the intake would restrict a lot of the airflow (pretending that the intake was not the issue), is the mere bore and stroke of the engine what causes a lack of higher-rpm performance from the L32 versus the L44?

Note, I have an H272 CAM that I'd be looking to install on the 3.4 V6/60... I what kind of base power could I expect from the 3.4 (which is otherwise rated at 160hp)? Maybe 170hp?

I'd be happy, realistically, to get somewhere close to 185hp when everything is said and done. Just weighing my options.


I appreciate any thoughts... (other than a totally different motor, I want to use the Fiero plenum).
Thanks!
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Report this Post05-10-2023 02:59 PM Click Here to See the Profile for sanderson231Send a Private Message to sanderson231Edit/Delete MessageReply w/QuoteDirect Link to This Post
Spend $70 fpr DynoSIM5 software and you can get a better idea. My experience with it is if you put a bigger displacement block on the same heads, same intake and same exhaust you get a lot less power than you think based on displacement increase.

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Report this Post05-10-2023 03:24 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Heads, intake, cams, and exhaust manifolds/Y pipe are all limiting. My 2.8 with the Comp 260H cam made peak HP at 5800 RPMs when I dyno'd it. I had mildly ported/gasket matched heads and intakes on mine along with ported exhaust manifolds and a custom Y pipe and 2.5" exhaust. I made 132RWHP which is probably about 160hp at the crank. This would probably equate to 185+ at the crank for the 3.4 at a slightly lower RPM on the 3.4 with my exact setup.

The dawg mod and boring out intake for larger 56mm TB would help too. I say go for it, not sure if LaFiera still offers his CNC ported heads for $700, but those with a hogged out intake + Dawg mod and 56mmTB will probably let the 3.4 breathe into the higher RPMs.

I don't think the stock bottom end wants to rev out super high but should be fine to make peak power near 6000RPMs for nice power overall for a Fiero without much effort and cost.

Double cut carbide burrs are a must for porting iron heads if you choose to port them yourselves, but for the aluminum intakes I would stick to the sanding rolls to avoid removing material too quickly. I get the kits with like 100 sandpaper rolls from Harbor Freight for dirt cheap.

An air die grinder is much nicer than electric as there is much less mass in the rotating components, which makes it much easier to not overdo it or make mistakes.

I like to move from port to port instead of doing each port one after another as it makes it much easier to stay consistent from port to port. It is probably 10-15 hours of work to port everything yourself, and less if you get already ported heads as they are the trickiest and most time consuming part of the job. Blending the bowls is a must as there is a wicked lip in the transition that really hurts flow.

[This message has been edited by zkhennings (edited 05-10-2023).]

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Report this Post05-10-2023 03:51 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by sanderson231:

Spend $70 fpr DynoSIM5 software and you can get a better idea. My experience with it is if you put a bigger displacement block on the same heads, same intake and same exhaust you get a lot less power than you think based on displacement increase.




Thanks, I'll buy that tonight. Never heard of that software.

So, I bit the bullet, and just bought the engine a few minutes ago... hahah.

In this case I bought the long block, so it comes with the heads. I think when you compare the exhaust for the F-body, the Fiero's exhaust is going to be a bit more open, but I think the intake is going to be a bit more restrictive. I do think I'll get more than 160hp, so I'm not concerned there... but I think I'm going to try to take advantage of some of the other improvements, like the fact that it uses a crank position sensor. I'm going to be using a newer / aftermarket ECM system, and that while I don't need to use that, I certainly can. I'll still be using the distributor though. It's currently capped off on the F-body engine, but the existing cam already has the gears for it. I would be looking to replace that though if I can get better performance with my H272.
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Report this Post05-10-2023 04:02 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post

82-T/A [At Work]

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quote
Originally posted by zkhennings:

Heads, intake, cams, and exhaust manifolds/Y pipe are all limiting. My 2.8 with the Comp 260H cam made peak HP at 5800 RPMs when I dyno'd it. I had mildly ported/gasket matched heads and intakes on mine along with ported exhaust manifolds and a custom Y pipe and 2.5" exhaust. I made 132RWHP which is probably about 160hp at the crank. This would probably equate to 185+ at the crank for the 3.4 at a slightly lower RPM on the 3.4 with my exact setup.

The dawg mod and boring out intake for larger 56mm TB would help too. I say go for it, not sure if LaFiera still offers his CNC ported heads for $700, but those with a hogged out intake + Dawg mod and 56mmTB will probably let the 3.4 breathe into the higher RPMs.

I don't think the stock bottom end wants to rev out super high but should be fine to make peak power near 6000RPMs for nice power overall for a Fiero without much effort and cost.

Double cut carbide burrs are a must for porting iron heads if you choose to port them yourselves, but for the aluminum intakes I would stick to the sanding rolls to avoid removing material too quickly. I get the kits with like 100 sandpaper rolls from Harbor Freight for dirt cheap.

An air die grinder is much nicer than electric as there is much less mass in the rotating components, which makes it much easier to not overdo it or make mistakes.

I like to move from port to port instead of doing each port one after another as it makes it much easier to stay consistent from port to port. It is probably 10-15 hours of work to port everything yourself, and less if you get already ported heads as they are the trickiest and most time consuming part of the job. Blending the bowls is a must as there is a wicked lip in the transition that really hurts flow.




Thanks for the info! I appreciate it! Yeah, I have the 56mm throttle body (or whatever it was) from way back in the day. There was a guy in the early 2000s who was doing these, his name was Darrel Morse. I went with his kit where he bored out the existing throttle body, and well into the intake plenum. That said, and like you said... it's still the neck that's the problem... so I will definitely have to do the dawg mod. I've never welded with aluminum, only have a basic mig welder, but hopefully it shouldn't be too hard.

I've already done port-matching of all the intake components from intake to plenum, but I'll go over it again to smooth it out with the rollers like you said. I'm nervous about doing it to the cyl heads, especially since this will be a long block, do I really want to remove the cyl heads, haha... but I might as well.

"Blending the bowls is a must as there is a wicked lip in the transition that really hurts flow."

I remember hearing about this. Do you have anything I can reference? Is there a good write-up anywhere on this?


"I don't think the stock bottom end wants to rev out super high but should be fine to make peak power near 6000RPMs for nice power overall for a Fiero without much effort and cost."

When you say this, you mean the 2.8 and 3.4 in general, or the 3.4 more so than the 2.8? Yeah, 6,000 rpms would be perfect, I wouldn't want to go more than that, I'd just like to know that I'd be able to continue to produce some kind of power through the mid-5,500 rpm range.

~185hp, as you kind of eluded to, is really all I'm looking for. I would be very happy with that. As others have said in some other threads... I'm getting older, and what I want has changed a lot. It used to be back in the late 90s, I viewed my Pontiac Fiero as a serious sports car and something that was super awesome... and I'd cruise all around Miami and race Porsche 944s and Mazda RX-7s and other cars and I just thought I was the **** . I'm in my mid-40s now, and I recognize that a 200hp Accord Sedan would leave me in the dust. At this point, I just want my Fiero to "feel" like it did when I was a kid, run well, and have fun with it... I won't be winning any races out here in rural Tampa!
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Report this Post05-10-2023 04:49 PM Click Here to See the Profile for cvxjetSend a Private Message to cvxjetEdit/Delete MessageReply w/QuoteDirect Link to This Post
I know that the High-rpm fans will tell you all day long that "Spinning the engine is the only way to GO!" but....I have the 3.4 F-body swap that nets you 20 more horseys and 30 Lb/Ft of torque.....This would not even knock a second off your 0-60 time...But I am a full second quicker and that was with a bunch of Cat-Crap in my exhaust and the stock intake- I have now opened the pinch point in the intake and shaken out the exhaust....i suspect I will then be at 6 seconds vs the stock 7.5 0-60.

Having your power-band at a lower RPM is just like installing a better gear ratio in your final drive.....But without the buzzing down the freeway at 4000 rpm @ 60 mph.

Also, lower RPM engines will generally have a wider power band, while the high RPM engines have a very narrow band; My 3.4 is over 100 HP from 2500 to 5000 (Half the rpm band)....The Honda Del Sol 1.6 L four has the same 160 HP (But at 7500) but the cripling thing is that the torque peak is at 7000....It is over 100 hp from 6000 to 7500(1/5 the RPM band)....every time I shift I stay ABOVE 100 HP, while the Del Sol drops to 78 hp (1st-2nd) 83 hp (2nd-3rd) 90 hp (3rd-4th) and finally on the 4th to 5th it is close to 100 at 98 hp.
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Report this Post05-10-2023 05:26 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I was referring to the 3.4 would probably be happy revving out to 6k if it can breathe, the 2.8 can probably go a little higher due to rod/stroke ratio and lighter pistons.

Check out Eric Weingartner's vids, super informative. The iron heads are exceptionally egregious when it comes to extremely poor blending of where the valve seat has been machined relative to the cast port bowl that is flowing into it.

There are several vids in this series:

https://www.youtube.com/watch?v=-Y5RODX3L0k&t=1s

Also I disagree about cars making power low down having longer power bands. It really depends on all the mods and the cam. I think what you really mean is that high hp low displacement screamers make very little torque at any point and make all their hp at high rpms. With 3.4 liters you will always have torque and if you can use cam and flow to extend that torque into higher rpms, you will make more horespower.

Here is my dyno graph, as you can see even though peak hp is close to 6k, it is making torque the entire time. This is what you want, a torque curve that peaks in the middle and is sustained across the rev range.



You don't want a flat HP graph, you want a flat torque curve and a linear hp curve that is constantly rising until your ideal shift point. In fact even if you do sacrifice bottom end torque, it only helps save the drivetrain and makes the car more driveable as you aren't lighting up the tires coming out of a turn as you get on the gas. A torque curve that is falling the entire rev range (flat hp graph) will only feel like the car is pulling slower as you climb up the revs. Flat torque curve makes the car pull hard at all times. Do you want your Fiero to feel like a diesel truck or like a sports car?

[This message has been edited by zkhennings (edited 05-10-2023).]

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Report this Post05-10-2023 06:51 PM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
The F-body 3.4 is stuck at 160 hp out of the box because it's still using a stock Fiero cam and ports cast for 2.8L worth of flow.

The 3X00 v6 engines have technical differences that give them more hp out of the box:

- A roller cam with roller lifters and more cam lift to match the exhaust lift and 1.6 ratio roller fulcrum rockers
- A smaller diameter crank pulley.
- Valves with a thinner valve stem which inherently flow more air for the same diameter valves.

The 3500 that is related to the 3900 also uses narrower rods and is a lighter rotating assembly giving it a few more HP over the 3500 that is based on the 3400.

They all use higher compression than the F-body 3.4

If you were willing to apply these enhancements to a rebuild, as I and La Fiera (and originally Fierosound) have, you'd make comparable power as we have shown.

I actually use 3400 blocks since a rebuild is planned anyway and hence use the roller cam setup as Fierosound detailed. The starter holes are already on the correct side.

The stock Y pipe sucks too...

You'll still need to modify the intake and throttle-body for more flow though. That's unavoidable as again it was barely good enough for a 2.8L engine.

[This message has been edited by lou_dias (edited 05-10-2023).]

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Report this Post05-10-2023 07:05 PM Click Here to See the Profile for pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:
I don't think the stock bottom end wants to rev out super high but should be fine to make peak power near 6000RPMs for nice power overall for a Fiero without much effort and cost.


To my knowledge, the bottom end of a DOHC LQ1 spins to 7k and is the pretty much the same as the bottom end of any other 3.4.

 
quote
Originally posted by lou_dias:
I actually use 3400 blocks since a rebuild is planned anyway and hence use the roller cam setup as Fierosound detailed. The starter holes are already on the correct side.


Why aren't you using 3400-based 3500 LX9 blocks for your iron-head projects?

For that matter, why hasn't this caught on in a larger sense?

Does this not work?
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Report this Post05-10-2023 07:13 PM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by pmbrunelle:


Why aren't you using 3400-based 3500 LX9 blocks for your iron-head projects?

Does this not work?

Yes, I just overbored a 3400 to 3.7" aka 3500. I also had the rod journals turned down to 2" so I can use 3500/3900 style lighter rods and my crankshaft lost 6.5 lbs after balancing

It hasn't caught on because most Fiero owners are cheap. They'd rather spend 20 years on one swap with a used engine than a few months and some coin on a proper performance rebuild with essentially a brand new engine.

[This message has been edited by lou_dias (edited 05-10-2023).]

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Report this Post05-10-2023 07:35 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:

I was referring to the 3.4 would probably be happy revving out to 6k if it can breathe, the 2.8 can probably go a little higher due to rod/stroke ratio and lighter pistons.


Ok, that's what I had kind of heard / thought... so I'm not missing a whole lot. But... let me ask you. I've gotten in touch with the rebuilder who's providing the engine to AutoZone. I've asked them if they're willing to do some additional work to the engine before they send it to me. If I ask them to rebalance the rotating assembly to a significantly higher degree than they normally do to "spec" ... will this help me in any way?


 
quote
Originally posted by zkhennings:
Check out Eric Weingartner's vids, super informative. The iron heads are exceptionally egregious when it comes to extremely poor blending of where the valve seat has been machined relative to the cast port bowl that is flowing into it.

There are several vids in this series:

https://www.youtube.com/watch?v=-Y5RODX3L0k&t=1s


This is awesome... when I did my intake port matching like 15-20 years ago, I used those shitty conical grinding stones that you'd buy at the local auto parts stores. Definitely not what he's using. I'm definitely going to watch these... thanks!


 
quote
Originally posted by zkhennings:
You don't want a flat HP graph, you want a flat torque curve and a linear hp curve that is constantly rising until your ideal shift point. In fact even if you do sacrifice bottom end torque, it only helps save the drivetrain and makes the car more driveable as you aren't lighting up the tires coming out of a turn as you get on the gas. A torque curve that is falling the entire rev range (flat hp graph) will only feel like the car is pulling slower as you climb up the revs. Flat torque curve makes the car pull hard at all times. Do you want your Fiero to feel like a diesel truck or like a sports car?



That makes sense. On your graph, your torque is VERY surprisingly flat once it hits it's peak. I've never seen that before in a V6/60... is this normal? All the graphs that I've seen, the torque curve slowly tapers off... but yours looks more like a sine wave once it hits it's peak, which is wild.


 
quote
Originally posted by lou_dias:

The F-body 3.4 is stuck at 160 hp out of the box because it's still using a stock Fiero cam and ports cast for 2.8L worth of flow.


The CompCams H272 cam, that's got a longer duration, correct? If I'm not mistaken, the duration refers to the length of time the valves stay open, so even with everything else being stock, I should still see SOME improvement with the H272 and 1.52:1 roller rockers (both of which I already have anyway), right?


 
quote
Originally posted by lou_dias:
They all use higher compression than the F-body 3.4



Yeah, I noticed that the 3.4 has a compression of 9.0:1, which is at least superficially better than the 8.9:1 of the 2.8, haha. Mine has been rebuilt, so there's been some surface work to it... so maybe it'll be a 9.1:1... one can only hope! Haha.


 
quote
Originally posted by lou_dias:
The stock Y pipe sucks too...

You'll still need to modify the intake and throttle-body for more flow though. That's unavoidable as again it was barely good enough for a 2.8L engine.


Back in the 2000s, someone on Fiero.NL was selling aftermarket and ceramic coated performance Y-pipes. I bought one of those that was mandrel bent with a 2" overall diameter, with the professionally designed Y section, etc. So what I have is at least decent.

My throttle body has already been bored (with it mounted to the intake)... it was done by Darrel Morse back in like 2000 or something like that. I still need to open up the underside of the neck though. Even though some work was done to it... obviously, that's going to be my biggest bottle-neck of everything.


 
quote
Originally posted by lou_dias:

It hasn't caught on because most Fiero owners are cheap. They'd rather spend 20 years on one swap with a used engine than a few months and some coin on a proper performance rebuild with essentially a brand new engine.



Hahah, I hope you're not lumping me into this. It's not about being cheap (though there's no reason to waste money). I'm more about getting a reasonable power increase, keeping the Fiero totally stock looking, while improving reliability as much as possible.

So I'd love to have a 3400 block like what was in the Grand Ams during the late 2000s. I loved those engines, they were smooth, pulled hard... and sounded awesome... like a more refined Fiero engine. But for me, getting rid of the Fiero intake plenum is a big no-no. I'm also going to stick with the distributor (even though I could go to DIS), simply because for me it's about maintaining originality.

This was my first car... literally... my 87 Fiero was THE car I drove in high school. Dude... all the chicks dug my Fiero, it was bad-ass. And when I moved to Miami, I used to cruise around in it all the time in the late 90s... up and down Fort Lauderdale and South Beach. Hahaha... It was always awesome when I took a girl out on a date (who knew nothing about cars) and they'd say... "Hey, this is a really nice car!"

Oddly enough, my wife HATES Fieros, and I had blown the engine and bought a 1997 Grand Am when I'd met her in 2000. She said if she knew I had a Fiero, she wouldn't have dated me because all the Fiero owners when she was in high school were assholes. Hahaha...


Anyway, my priorities are:
- Originality
- Reliability
- Performance
- Economy

Really... I could care less about economy... because more than likely, once I actually totally restore my Fiero, it'll sit in the garage next to my 2002 Crown Victoria (which has 46k miles on it), and it'll never get driven and probably started once every 6 months.
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Report this Post05-10-2023 08:04 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I did not realize the 3.4 bottom end and DOHC bottom end are identical. I know the 3.4 DOHC has a better oil pump but it also has to feed all those cams. Still figured there were some differences.

In regards to the waviness of the dyno plot up top, it could be they didn’t use enough smoothing factor, or it could be the beginning of valve float as I was running the performance cam and 1.6 ratio stamped steel rockers with stock valve springs.

But yes the 260H cam has 260 degrees of duration on intake and exhaust, much higher then the stock 2.8 cam, and this plus the other specs of the cam help the engine breathe better which lets the power keep climbing. I don’t think my cam caused me to lose any bottom end really compared to stock.

A more aggressive cam would lose some bottom end but make more power up top than what you see on my dyno. This is because as duration gets longer on intake and exhaust they start to overlap, and at low engine speeds you lose a bunch of intake charge out of the exhaust because the intake valve stays open longer and the exhaust valve opens earlier. But to take full advantage of it you will need more extreme intake and exhaust mods to support the extra flow. The sweet spot is where you take full advantage of the flow you have and no more. 272 cam may be perfect, as I felt my engine could have used a touch more cam. Expect to buy stiffer valve springs though, may require some machining to the seat to get the correct install height, but there may be offset keepers available to change install height without and machine work necessary.

The 3500 bottom end would be a good upgrade too but require more work, you’d have to get different pistons. The roller cams are basically able to open the valve faster and hold it near peak longer, so it will increase flow, and it’s also an extremely robust bottom end that you can put a fiero top end on top of (and install a dist as is). This would be Fiero heads and intake, and even timing cover alternator waterpump etc. It would appear as stock as a 2.8.

[This message has been edited by zkhennings (edited 05-10-2023).]

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Report this Post05-10-2023 08:06 PM Click Here to See the Profile for pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:
Hahah, I hope you're not lumping me into this. It's not about being cheap (though there's no reason to waste money). I'm more about getting a reasonable power increase, keeping the Fiero totally stock looking, while improving reliability as much as possible.

So I'd love to have a 3400 block like what was in the Grand Ams during the late 2000s. I loved those engines, they were smooth, pulled hard... and sounded awesome... like a more refined Fiero engine. But for me, getting rid of the Fiero intake plenum is a big no-no. I'm also going to stick with the distributor (even though I could go to DIS), simply because for me it's about maintaining originality.


Maybe you misunderstood, but Lou was talking about using the 3400 block (without cylinder heads) and bolting the Fiero heads and intake onto the 3400 block, maintaining the original appearance.

I was talking about using the 3500 LX9 block (without cylinder heads) and bolting the Fiero heads and intake onto it, for even more displacement, still keeping the original Fiero appearance.
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Report this Post05-10-2023 08:28 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:

The 3500 bottom end would be a good upgrade too but require more work, you’d have to get different pistons. The roller cams are basically able to open the valve faster and hold it near peak longer, so it will increase flow, and it’s also an extremely robust bottom end that you can put a fiero top end on top of (and install a dist as is). This would be Fiero heads and intake, and even timing cover alternator waterpump etc. It would appear as stock as a 2.8.



 
quote
Originally posted by pmbrunelle:

Maybe you misunderstood, but Lou was talking about using the 3400 block (without cylinder heads) and bolting the Fiero heads and intake onto the 3400 block, maintaining the original appearance.

I was talking about using the 3500 LX9 block (without cylinder heads) and bolting the Fiero heads and intake onto it, for even more displacement, still keeping the original Fiero appearance.



Well **** ... hahah... I just bought the 3.4 Gen-1 long block. I wish I had done a bit more research, but I assumed the heads didn't match up. Oh well... I'm still pretty content with the normal 3.4. I would have liked a roller cam, but it's ok.


Thanks for all the other info!
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Report this Post05-11-2023 07:02 AM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Several years back there was a dyno day where several 2.8, 2.9, 3.1, and 3.4 Fieros were put on the dyno.
https://www.fiero.nl/forum/...130314-1-082335.html
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Report this Post05-11-2023 08:27 AM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroguru:

Several years back there was a dyno day where several 2.8, 2.9, 3.1, and 3.4 Fieros were put on the dyno.
https://www.fiero.nl/forum/...130314-1-082335.html



Wow! That is a FANTASTIC thread.

The only thing I question on there is why the 3.1 fell on its face so hard in the upper RPMs. It fell off like a rock much more than all the other cars, though it did second best in the lower rpms. But the 3.4 really killed it across the board.

The Truleo intake graph later on down the thread really also shows how much improvement could be made by allowing that engine to breath properly. Really emphasizes the need to do the DAWG or whatever it's called... opening up the neck.


Thanks for sharing this!


EDIT: I see... Don's engine (the 3.1) was babied a little bit simply because he had just rebuilt it and didn't want to push it. My guess is it still didn't have the torque and low-end power of the 3.4, but likely would have really competed with the 3.4 in the upper end.

Interesting to note too that the 3.4 in those dyno graphs was totally stock. Stock intake and exhaust (if I'm reading it right). Which means that possibly he didn't even bother to port-match or hog out the exhaust manifolds.

[This message has been edited by 82-T/A [At Work] (edited 05-11-2023).]

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Report this Post05-11-2023 09:22 AM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
Prior to doing the DAWG mod on my car and using wheels that were near stock weight, my motor made 187rwhp at ~4500 rpm and 249 ft*lbs at 3600 rpm.
After that I started using really heavy wheels for racing so all my subsequent dynos were gimped due to the extra rotating mass...but I eventually went on to make peak power at the advertised cam peak once I did further intake mods. I eventually did a mild refresh of the motor using a cam that peaked at 4900 rpm but had much more lift than the stock 3400 cam(.436/.436 @ 5200) I was using. (.480/.480). My new cam will use ~ .550 lift and peak between 6200 and 6400.... I am using 6" rods in the new motor and intend to rev to 7500 rpm.

While this thread was eventually invaded by butt-hurt trolls, you can see my early dyno on the 3rd page.
https://www.fiero.nl/forum/Forum2/HTML/075502.html

[This message has been edited by lou_dias (edited 05-11-2023).]

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Report this Post05-11-2023 09:48 AM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by lou_dias:

Prior to doing the DAWG mod on my car and using wheels that were near stock weight, my motor made 187rwhp at ~4500 rpm and 249 ft*lbs at 3600 rpm.
After that I started using really heavy wheels for racing so all my subsequent dynos were gimped due to the extra rotating mass...but I eventually went on to make peak power at the advertised cam peak once I did further intake mods. I eventually did a mild refresh of the motor using a cam that peaked at 4900 rpm but had much more lift than the stock 3400 cam(.436/.436 @ 5200) I was using. (.480/.480). My new cam will use ~ .550 lift and peak between 6200 and 6400.... I am using 6" rods in the new motor and intend to rev to 7500 rpm.

While this thread was eventually invaded by butt-hurt trolls, you can see my early dyno on the 3rd page.
https://www.fiero.nl/forum/Forum2/HTML/075502.html




That's a great thread. I think I remember reading somewhere that you (and a couple of other people) had used the newer roller blocks with the old heads... but it slipped my mind. I see you have to do some custom pistons for clearance, but otherwise... do the Gen-1 heads simply bolt on to the newer blocks without any other modification necessary? That's very, very cool.

I assume there's no problems with splayed versus non-splayed valves... it's just the angle of the pushrod into the lifter.


So, this image caught my attention:



I cringed when I first saw it, but it's intrigued me. I suppose what this is doing is equalizing the air flow between the ports. Did you notice a significant difference? (it says 22hp), but just curious on your thoughts...
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Report this Post05-11-2023 10:38 AM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
I lost something like 6 ft*lbs below 4500 (which I already had plenty of torque) but gained so much more power after 4800. The dyno I included speaks for itself. With a proper cam, the limitation isn't the heads as others will try to convince you otherwise. That said the heads are ported. I've made separate videos on my heads.

https://rumble.com/v2aonfa-...-v6-heads-redux.html

Follow the link to Fierosound's engine build about the roller lifters with iron heads. There's no needs to worry about the aluminum heads' splayed valves. The lifters go straight up and down, you just need shorter pushrods. They had to lower the height of the engine for FWD cars, hence they also use smaller valve covers. That's what pushed that design. If you look at LS3 heads, they are straight. Don't buy into the hype.

[This message has been edited by lou_dias (edited 05-11-2023).]

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Report this Post05-11-2023 12:09 PM Click Here to See the Profile for RaydarSend a Private Message to RaydarEdit/Delete MessageReply w/QuoteDirect Link to This Post
Having built a 3.4, I think you'll like the H272 cam. I used the Comp 1.52 rockers. Just be aware that you will need to machine the spring pockets in the heads, or use some different springs. Otherwise the springs will coil-bind. (If it's the same cam I'm thinking of, the valve lift is .454/.480, I/E, with 1.52 rockers.)
I would recommend the Dawg intake mod, and a bored throttle body and neck - at the very minimum. If you can find a Trueleo, that would be the stuff.
I used a Cloyes timing set that allowed for cam adjustment. I installed my cam retarded, relative to the crank, to help out the top end.
I had my heads ported and cleaned up, as well as the lower intake.
I also ran tuned headers.
So... how did it run? It felt almost as strong as my 4.9. (Tractor torque notwithstanding. )



[This message has been edited by Raydar (edited 05-11-2023).]

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Report this Post05-11-2023 12:57 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by lou_dias:

I lost something like 6 ft*lbs below 4500 (which I already had plenty of torque) but gained so much more power after 4800. The dyno I included speaks for itself. With a proper cam, the limitation isn't the heads as others will try to convince you otherwise. That said the heads are ported. I've made separate videos on my heads.

https://rumble.com/v2aonfa-...-v6-heads-redux.html

Follow the link to Fierosound's engine build about the roller lifters with iron heads. There's no needs to worry about the aluminum heads' splayed valves. The lifters go straight up and down, you just need shorter pushrods. They had to lower the height of the engine for FWD cars, hence they also use smaller valve covers. That's what pushed that design. If you look at LS3 heads, they are straight. Don't buy into the hype.



Few questions if you don't mind! (thank you for answering them)...

- I noticed you mention in your video that you're using the Fiero Store's stainless steel valves and valve springs. Quick question about that... how do you like them? What was it specifically that made you want to go down that path and use the Fiero Store's SS valves. I'm sure you don't have a before and after on JUST that... but curious what your thoughts are on using them?

- Exhaust Manifolds... I have a couple of junk Fiero V6 exhaust manifolds, and was thinking of cutting off the base and using them as a guide to help port my exhaust ports (rather than going the tape and etch route). Did you use any kind of template or something to help you in that area, or did you just mark it off (or use the exhaust staining) and grind that way?

- Water ports... I noticed both on your video, and in my own experience, that the water ports are always much smaller than the intake opening. I'm curious if it's not beneficial in any way to also port-match the water ports between the intake and the cyl head. Not like smoothing it out, because I recognize that a gritty interior passage just serves as more surface area with which to transfer heat, but... is there any benefit to port-matching the water ports?

- "Don't buy into the hype." I actually don't know what you're talking about here, haha... I haven't been involved in any of the back and forth.

Also, +1 for using Rumble...
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Report this Post05-11-2023 01:48 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Raydar:

Having built a 3.4, I think you'll like the H272 cam. I used the Comp 1.52 rockers. Just be aware that you will need to machine the spring pockets in the heads, or use some different springs. Otherwise the springs will coil-bind. (If it's the same cam I'm thinking of, the valve lift is .454/.480, I/E, with 1.52 rockers.)



When you say machined spring pockets... I had my engine rebuilt and they put thick washers under the springs to reinforce the head (for my older engine). I had a totally different performance cam. But when you say "use different springs," what would you recommend? When I get this motor, I would honestly prefer to not have to do any machining at all if possible since it'll have already been rebuilt. All I'll be doing is possibly replacing the valves (lapping them the old fashioned way with the spindle and suction cup, haha), and porting everything. If I can just buy the right springs, rather than having to modify the cyl head seats, that would be more ideal. Thanks!!!


 
quote
Originally posted by Raydar:
I would recommend the Dawg intake mod, and a bored throttle body and neck - at the very minimum. If you can find a Trueleo, that would be the stuff.


I've got the bored throttle body and neck, but don't have the dawg mod to expand the overall opening of the neck, so I will definitely do that, or something close to it. Goal is for me to keep it stock looking though, so the Trueleo isn't an option. I think if I wasn't concerned about looks... I'd probably go with a 3500 engine from the Pontiac Montana. Came stock w/ 185hp and more torque than all the other implementations of that motor.


 
quote
Originally posted by Raydar:
I used a Cloyes timing set that allowed for cam adjustment. I installed my cam retarded, relative to the crank, to help out the top end.


I think I'm going to do this as well. I have a set of Cloyes timing gears that i put on my other engine... are they still available?


Thank you!

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Report this Post05-11-2023 02:00 PM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:


Few questions if you don't mind! (thank you for answering them)...

- I noticed you mention in your video that you're using the Fiero Store's stainless steel valves and valve springs. Quick question about that... how do you like them? What was it specifically that made you want to go down that path and use the Fiero Store's SS valves. I'm sure you don't have a before and after on JUST that... but curious what your thoughts are on using them?

- Exhaust Manifolds... I have a couple of junk Fiero V6 exhaust manifolds, and was thinking of cutting off the base and using them as a guide to help port my exhaust ports (rather than going the tape and etch route). Did you use any kind of template or something to help you in that area, or did you just mark it off (or use the exhaust staining) and grind that way?

- Water ports... I noticed both on your video, and in my own experience, that the water ports are always much smaller than the intake opening. I'm curious if it's not beneficial in any way to also port-match the water ports between the intake and the cyl head. Not like smoothing it out, because I recognize that a gritty interior passage just serves as more surface area with which to transfer heat, but... is there any benefit to port-matching the water ports?

- "Don't buy into the hype." I actually don't know what you're talking about here, haha... I haven't been involved in any of the back and forth.

Also, +1 for using Rumble...

The Fiero Store SS valves very slightly bump compression over stock and near the base of the valve get about 1 mm narrower to increase flow over stock.
You should try to get some Trueleo headers. My exhaust ports were done/started on a machine to make them perfectly round and centered then internally blended by hand.
The Fiero cooling system is plenty fine so if it ain't broke, I don't fix it.

Headers and Cross-over:
https://www.youtube.com/watch?v=A6b6oFadliQ

Installed along with the old Trueleo intake after my refresh to the 4900rpm 480/480 roller cam:
https://www.youtube.com/watch?v=6IUNb-H53Io

[This message has been edited by lou_dias (edited 05-11-2023).]

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Report this Post05-11-2023 04:44 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have no beef with anyone about anything, I don't care one bit what heads anyone wants to put on what bottom end, but the splayed valve tech is objectively really nice, it does an excellent job de-shrouding the valves as the valve moves away from the cylinder wall. Most DOHC high flowing motors have the same concept as they all have hemi heads (like a Chrysler hemi engine does with 2 valves, hence the name, hemispherical combustion chamber), and the valves are splayed but in a different plane. I have watched a lot of videos on head flow and de-shrouding the valves massively increases flow on Chevy V8s, as the biggest restriction by far in the head is nowhere in the port, it is when the air needs to flow around and past the valve. Port shape is all about helping the air slip past the valve and into the combustion chamber. You lose somewhere around 20% of flow out of the valve when it is butted up next to the cylinder wall.

On the intake side, the flow around the valve also greatly benefits from getting rid of the tulip shaped part of the valve. Here you can see an image comparing an LZ9 intake valve to a 2.8 intake valve, notice how much flatter the LZ9 valve is. You can make these mods yourself with a drill and an angle grinder, a drill to spin the valve and an angle grinder to remove material. On the exhaust side the tuliping helps as gas is flowing past the valve in the reverse direction and the tuliping plays a positive role in redirecting it to flow out the port.

You can see how in the newer motors they have reduced the diameter of the valve stem, and they have flattened the back of the valve, both for lightness and for flow. This is LZ9 intake valve vs 2.8 intake valve.

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Report this Post05-11-2023 06:13 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
If you don't ditch the stock Fiero intake with Dawg mod or anything else you'll be very disappointed. The difference between the L44 and the L32 is not only the displacement, but another parameter that a lot of people don't take into account because they've heard it is not important. I'm taking about rod to stroke ratio or rod ratio which is the relation between the rod lenght and stroke. I have to go to a meeting and when I come back later tonight I can get deeper in the discussion so you can understand why is it when you dress the 3.4L with all the Fiero intakes and exhaust it falls off on its face much earlier in the RPM range. And how you can compensate for that.
Meantime I'll leave you with my 2 experiments. And no, there's not turbo, supercharger or nitrous, all NA.



Stock 2.8 VS Same 2.8 built without generic parts from catalogs. (Intake, CNC heads stock valves & custom cam.)



3.4L (Intake, CNC heads oversized valves, custom cam and 3.4DOHC pistons)
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Report this Post05-11-2023 06:38 PM Click Here to See the Profile for pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:
I have no beef with anyone about anything, I don't care one bit what heads anyone wants to put on what bottom end, but the splayed valve tech is objectively really nice


Objectively... I would say that the iron heads with all their 90° angles and parallel valves are really nice with regards to the number of machining setups and ease of setup.

The splayed valve heads don't seem nice at all with regards to having to set up a production line to make them...
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Report this Post05-11-2023 10:07 PM Click Here to See the Profile for MarkSSend a Private Message to MarkSEdit/Delete MessageReply w/QuoteDirect Link to This Post
Might want to look through this old thread. Not promoting a carb so much as what a 3.4 could do.
https://www.fiero.nl/forum/...060206-2-066575.html
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Report this Post05-12-2023 12:40 AM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think one of his key goals is to keep it looking stock, it will still be a big improvement.
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Report this Post05-12-2023 08:47 PM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by MarkS:

Might want to look through this old thread. Not promoting a carb so much as what a 3.4 could do.
https://www.fiero.nl/forum/...060206-2-066575.html


What most people don't realize is that 'Mustang' brand dynos are wildly different because they get 'tuned' by each shop individually. The particular one I went to got his within 5% of dynojet dynos...most are 15% lower... So my 187 rwhp is 95% of what it would have done on a local dynojet (which are pretty standardize for output results). You'd have to go to two local dynos and do your own comparison if you have a Mustang and Dynojet dyno shop(s) around. I had more work into my motor (hence 249 ft*lbs) but at the same time I was restricted by the stock intake neck as that pre-dated my DAWG mod...which is also why my peak rpm was <=4500 rpm...when it should have been at 5200 rpm.

I did go onto remove that restriction but you'll notice my future dyno got lower... Why? They co-inside with putting on bigger, wider, heavier wheels. So I sacrificed "rwhp" in the name of launching and grip on the track. It was worth it because that was how I was measuring 'performance' for my use-case....the oval track.

The bottom line is that a properly built 3.4 can and will do >200 rwhp...as the above dynos, La Fiera and others have proven.

[This message has been edited by lou_dias (edited 05-12-2023).]

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Report this Post05-12-2023 10:28 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:

the splayed valve tech is objectively really nice, it does an excellent job de-shrouding the valves as the valve moves away from the cylinder wall. Most DOHC high flowing motors have the same concept as they all have hemi heads (like a Chrysler hemi engine does with 2 valves, hence the name, hemispherical combustion chamber), and the valves are splayed but in a different plane. I have watched a lot of videos on head flow and de-shrouding the valves massively increases flow on Chevy V8s, as the biggest restriction by far in the head is nowhere in the port, it is when the air needs to flow around and past the valve. Port shape is all about helping the air slip past the valve and into the combustion chamber. You lose somewhere around 20% of flow out of the valve when it is butted up next to the cylinder wall.

On the intake side, the flow around the valve also greatly benefits from getting rid of the tulip shaped part of the valve. Here you can see an image comparing an LZ9 intake valve to a 2.8 intake valve, notice how much flatter the LZ9 valve is


My intake valves VS stock 2.8/3.4.
Yes, the splayed is nice but when I wanted to take that advantage to use it on my stroker I found that the camshaft profile reveled its flaw. When I installed the cam profile specifically made for the displacement, due to the LSA and Overlap the intake and exhaust valves hit each other and locked together. So, as you can see all those DOHC engines have the valve area to use a lot less overlap and less aggressive LSA's but when it comes to the Hemis, they are leaving a lot on the table because they can't get aggressive on LSA's and overlap for the displacement.
I fixed the shrouding problem by widening the bore and voila, problem solved. Same head went from 193CFM to past 220CFM by increasing the bore and making the intake valve 5% bigger and reducing the valve stem by 20%. The junyard 39000/3500 motors everyone uses to upgrade their Fieros cost money, a bunch of time and lots of custom work. I'm with Lou, why spend so much money and more important time when for the same money or a bit more you can put together a 3.4/3400 iron headed package than can outperfom any LZ/LX9? To each their own

This is the perfect example.
https://youtu.be/vdTY9J9crQw

Again, like Zkennings said, I don't care what you use and I respect that. It is your car/engine/project.

[This message has been edited by La fiera (edited 05-12-2023).]

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Report this Post05-14-2023 11:19 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
Removed because It is not my thread, sorry T/A!

[This message has been edited by La fiera (edited 05-15-2023).]

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Report this Post05-16-2023 09:28 AM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:

Removed because It is not my thread, sorry T/A!




NO! I was just going to respond to it, but got caught up in other things and needed to read it more fully.


I'm trying to remember what you put. You had talked about duration and lift of a cam. I'm trying to member what the point was, but something to the effect that there's a sweet spot and too much lift isn't good, but with a 3.4 having more feet (distance) traveled than the 2.8's stroke... I can't remember. Any chance you can put it back?

I've not responded to this thread because it takes more brainpower than arguing on the Politics forum, or shooting the **** in the T/OT, so I've been going to it and contemplating what questions I have. That post was useful ...
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Report this Post05-16-2023 12:40 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:


The junyard 39000/3500 motors everyone uses to upgrade their Fieros cost money, a bunch of time and lots of custom work. I'm with Lou, why spend so much money and more important time when for the same money or a bit more you can put together a 3.4/3400 iron headed package than can outperfom any LZ/LX9? To each their own




I really don't think there is a right answer, some people are comfortable with fab but not engine building, they are totally different skills. You have quite a lot of fab in your motor with the headers and intake that most people that could do a swap could not make. There are cheap and easy ways to swap in the newer motors. Also building a 3.4 or 3400 bottom end with Fiero top end still requires buying a motor which is probably very close in price to any 3X00 motor.

Personally I built a mild 2.8, and I got 132rwhp, it was not any cheaper than the cost to build the LZ9. I picked up my LZ9 for $300 and I could have run it stock as it was in great shape, but I wanted to build it. My LZ9 build isn't any more expensive than building a 2.8 or 3.4, cam, pushrods, machine work, labor, and I am going to get way more power out of it than my 2.8 which was the same effort and cost to build. If I wanted the same power out a 3.4, I would need to put quite a bit more money and experience into all the mods. I have spent very little money on the actual swap part of it all, the most expensive part being the megasquirt and all the wiring and stuff for it. But this would be required for a 2.8/3.4 too if you go really wild to make equivalent power. So really the only extra work with a swap is getting all the lines plumbed up, a couple motor mounts, and an alternator mount, very low effort overall compared to everything else. Most people's swaps (like mine) take time because they improve other areas, for example I fabbed in a new 2x3" crossmember because the stock one is wicked weak, it was not a necessary change.

And it is never mentioned really that if you desired you can swap the 2.8 front motor mount, timing cover, water pump, alternator bracket, and dog bone bracket onto any 3X00 motor and not have to do any fab. All the coolant lines and mounts can be stock, you just need a corvette returnless fuel filter to get the fuel system hooked up, a way to mate the Fiero filter housing to the 3X00 throttle body, and some pretty simple splicing of maybe 10 wires in the harness. However I wanted the recirculating coolant system to remain intact as it is nice new age tech, and I like to engineer things.

I get that you want to encourage people to build their motors vs do swaps, but the top end of the motor being different is not what causes these swaps to take any more or less time than building a stock motor, and especially not if you are starting with a 3.4 or 3X00 bottom anyways and swapping Fiero stuff onto it. It just comes down to what people have time to work on in their busy lives. I am a big fan of your builds and your old racing footage on youtube, but I wanted the most ultimate version of the pushrod 60*V6 to go in my car as it is an evolution of the stock motor which I find very clean in terms of a swap.

I am most likely going to make 260+rwhp with a mild build, the same mild build I did to my 2.8 and got 132rwhp, probably 160+ if I started with a 3.4. The swap part of it is fun and I can re-invent a bunch of things to make the car stronger and easier to work on, the swap part is not super expensive unless you want it to be. To make 260+rwhp with a 3.4 will cost me quite a bit more money and there is a good chance it is less reliable as I am far exceeding what the factory designed it to handle. I will probably get much better mileage with my LZ9 as well than compared the equivalent 3.4 build making the same HP, which matters to me as I want to daily it during the warm NE months.

Can we just end this argument? There are so many ways to achieve a power goal, and different factors make the choice different for different people. There's no need to bash each other's choices, and this is really me responding to all the 3X00 bashing.

What I would love to see is build a motor like Lou's with a roller bottom end but actually put your CNC heads on it with a factory looking intake (because most people that want to stay stock heads do so to retain a factory looking intake, like this current thread) that does not need to be heavily fabricated and get some dyno numbers. If people actually had a blueprint for building a "factory+" motor that didn't break the bank and actually revved out to 6000+, then they would do it, and I am sure you could achieve that.

Lou's motor is great for what he does with it, spectator drags, perfect. Makes great torque down low and punches off the line and out of the corners. Your motor is extremely impressive and built to scream on the racetrack, that's wicked awesome, it is designed to live at high RPMs. But I wanted a motor I can drive every day that is not too extreme and still makes good vacuum at idle that I can also rev out to 7000RPMs with a long usable torque curve and that gets decent gas mileage, all without going super crazy on modifications to the motor and keeping it NA, while also keeping the car looking stock on the exterior. Those are my goals and probably the goals of many others too. Achieve this with a rebuild vs an engine swap and people like me will do it. But I would not know how to do it by myself, but I sure as hell can fab some mounts, brackets, and adapters and throw parts I can buy off the internet into a $300 motor. I feel like this is where the disconnect exists and why so many people chose to swap.
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La fiera
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Report this Post05-16-2023 08:21 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by zkhennings:
I get that you want to encourage people to build their motors vs do swaps, but the top end of the motor being different is not what causes these swaps to take any more or less time than building a stock motor, and especially not if you are starting with a 3.4 or 3X00 bottom anyways and swapping Fiero stuff onto it. It just comes down to what people have time to work on in their busy lives. I am a big fan of your builds and your old racing footage on youtube, but I wanted the most ultimate version of the pushrod 60*V6 to go in my car as it is an evolution of the stock motor which I find very clean in terms of a swap.


That's the problem with writing and reading instead of having a conversation face to face with other parties. I think I came across pushing for building engines instead of swaps and that was not what I wanted to say. I'm a fan of what your are doing with the LZ9 because I haven't seen anyone going as far as you have and what I respect the most is that you are keeping it NA. I apologize for making you feel that I was criticizing your choice of swap. I can design custom parts but I don't have your welding skills or the know-how to do it in Solidworks or 360. I only took 2 years of Mechanical Engineering because I couldn't afford it back in the day. I will be reaching out to you so you can help me make a dxf file for a DIS wheel. And thank you for being a big fan!

Rei

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Report this Post05-16-2023 09:11 PM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
My only qualm about a $300 motor is that it's just a timebomb.

You *should* rebuild them all.

That's why I chose to rebuild a motor on the side similar enough to what was already there so that the swapping aspect is actually quite fast and simple.

[This message has been edited by lou_dias (edited 05-16-2023).]

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La fiera
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Report this Post05-16-2023 09:54 PM Click Here to See the Profile for La fieraSend a Private Message to La fieraEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by 82-T/A [At Work]:
NO! I was just going to respond to it, but got caught up in other things and needed to read it more fully.


I'm trying to remember what you put. You had talked about duration and lift of a cam. I'm trying to member what the point was, but something to the effect that there's a sweet spot and too much lift isn't good, but with a 3.4 having more feet (distance) traveled than the 2.8's stroke... I can't remember. Any chance you can put it back?

I've not responded to this thread because it takes more brainpower than arguing on the Politics forum, or shooting the **** in the T/OT, so I've been going to it and contemplating what questions I have. That post was useful ...


The 2.8L has a rod to stroke ration of 1.91 and the 3.4L yields a 1.72. You may say that its 0.19 difference does not matter right? Well, lets dig deeper.
The difference here is that the two engines share the same rod length at 5.7" inches and have different strokes, 2.99" for the 2.8L and 3.31 for the 3.4L. So, how does that makes a difference on performance? Let's make a scenario, both engines spinning at 6500rpms and lets pay attention at the piston velocity and piston location below deck between the two engines and how these two differences can make or break your project and how different cam timing events should be different between the two engines.
Let's lock the crankshaft degrees for the two engines at 90 degrees and see where the piston is in comparison to that piston speed. For the 2.8L the piston speed at 90 degrees of crank rotation in feet per minute is 5088.1 FPM. The 3.4L due to its longer stroke has the piston traveling at 5633 FPM at that same 6500rpms. That is 545 FPM or 6 MPH faster per down stroke at 90 degrees and at the same 6500rpms. So that means that the space on the 3.4L is bigger and needs to get filled up! And that is a way bigger space compared to the 2.8L!
We can also assume that the 3.4L has the piston lower in the bore at 90 degrees. The 2.8 is at 1.7 inches below TDC while the 3.4L is 1.9 inches below deck which equals a mere 0.2 inch advantage. That mere 0.2 advantage means the 3.4L can use a bit tighter camshaft LSA (assuming it is using the the Fiero heads) and a couple of degrees of overlap which will result in a bit longer cam duration compared to the 2.8L.
You noticed I mentioned LSA and overlap and then duration as a result. Cam duration is the least important factor because if you have the LSA and Overlap right, the Duration will be a mathematical result of LSA and Overlap. So the point is that Duration is not the defining factor of how big a cam should be for a specific engine.
Have you ever wonder why a cam works good on a 2.8L and on a 3.4L the same came fall on it face 700-1100rpms sooner?
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Report this Post05-16-2023 10:17 PM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
No worries I wasn’t taking anything personally, there’s just pros and cons to every choice when it comes to making more power.
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Report this Post05-17-2023 10:00 AM Click Here to See the Profile for lou_diasSend a Private Message to lou_diasEdit/Delete MessageReply w/QuoteDirect Link to This Post
A couple of 'upgrades' I recommend are switching to the '7730 ECM w/DIS so you can get rid of the distributor...
This allowed me to take a 2.8 Firebird intake and port it to 59mm down the whole straight neck and used a bigger throttle-body. This allows a 3.4 to breathe to ~6000 rpm. I had also opened up the ports and cut the gaskets for the larger ports.

In my case, I 3D-printed an adapter and used an L98 V8 throttle-body.

It can be seen here:
https://www.fiero.nl/forum/.../075502-18.html#p705

Ideally someone would weld in the FIERO intake plate and paint it red to look stock...and find a throttle-body that doesn't need an adapter.
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Report this Post05-17-2023 11:41 AM Click Here to See the Profile for zkhenningsSend a Private Message to zkhenningsEdit/Delete MessageReply w/QuoteDirect Link to This Post
Even if you choose to stay with a modified Fiero intake, going to DIS is a nice improvement, 3 coils instead of 1 lets them fire with full power at higher RPMs, and reading a crank sensor over the sensor in the dist is wayyy more precise for spark timing as you aren't dealing with slack in the timing chain and in the gear mesh between dist and cam. Also spark has to jump two gaps with a dist vs 1 with DIS, and you have to contend with more connections that all have the ability to add more resistance to the system further impeding good spark.
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82-T/A [At Work]
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Report this Post05-17-2023 03:21 PM Click Here to See the Profile for 82-T/A [At Work]Send a Private Message to 82-T/A [At Work]Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by La fiera:

The 2.8L has a rod to stroke ratio of 1.91 and the 3.4L yields a 1.72. You may say that its 0.19 difference does not matter right? Well, lets dig deeper.

For the 2.8L the piston speed at 90 degrees of crank rotation in feet per minute is 5088.1 FPM. The 3.4L due to its longer stroke has the piston traveling at 5633 FPM at that same 6500rpms.

That is 545 FPM or 6 MPH faster per down stroke at 90 degrees and at the same 6500rpms. So that means that the space on the 3.4L is bigger and needs to get filled up! And that is a way bigger space compared to the 2.8L!

We can also assume that the 3.4L has the piston lower in the bore at 90 degrees. The 2.8 is at 1.7 inches below TDC while the 3.4L is 1.9 inches below deck which equals a mere 0.2 inch advantage. That mere 0.2 advantage means the 3.4L can use a bit tighter camshaft LSA (assuming it is using the the Fiero heads) and a couple of degrees of overlap which will result in a bit longer cam duration compared to the 2.8L.


This makes perfect sense. So obviously the engine is producing more power because it has a larger displacement and bigger "bang," essentially... but the rotating mass has to work significantly more to produce it. Right?


 
quote
Originally posted by La fiera:
You noticed I mentioned LSA and overlap and then duration as a result. Cam duration is the least important factor because if you have the LSA and Overlap right, the Duration will be a mathematical result of LSA and Overlap. So the point is that Duration is not the defining factor of how big a cam should be for a specific engine.
Have you ever wonder why a cam works good on a 2.8L and on a 3.4L the same came fall on it face 700-1100rpms sooner?


So here's what I wanted to ask... you say that duration is less important. I had to look up what LSA meant because it wasn't immediately obvious to me, so I found this ...
https://www.enginelabs.com/...-power-relationship/

So I understand lobe separation now, to some extent. To be completely fair, when I look at the H260 and H272 cams, I kind of went under the assumption of what people were saying at any given point. Now that I'll be going with a 3.4 iron block and heads (and I do plan to port-match, etc.), what cam do you think would be most appropriate for my configuration?

The idea for me is to go with the 3.4, I'll have the stock intake... I might even have it extrude-honed... but I do plan to do the DAWG mod. I've never welded with aluminum, but I'll probably go that route and do it myself. I already have the bored out throttle body, and hogged out exhaust manifolds, 2" exhaust all the way through with the improved Y-pipe, and everything is ceramic coated to the catalytic converter (which is an Ocelot one).

Again... definitely want to say, I really appreciate all the time and effort. I know you guys aren't getting paid to give me advice, nor is it necessarily fun having to spend your time explaining things... so I really appreciate everyone giving me advice here, I really mean that. This has been extremely helpful.


 
quote
Originally posted by lou_dias:

A couple of 'upgrades' I recommend are switching to the '7730 ECM w/DIS so you can get rid of the distributor...


 
quote
Originally posted by zkhennings:

Even if you choose to stay with a modified Fiero intake, going to DIS is a nice improvement, 3 coils instead of 1 lets them fire with full power at higher RPMs, and reading a crank sensor over the sensor in the dist is wayyy more precise for spark timing as you aren't dealing with slack in the timing chain and in the gear mesh between dist and cam.



Hahah... you guys are going to be mad at me. If you remember... I plan on going with the FAST EZ-EFI 2.0, haha.

I really, really thought about a DIS ignition. Especially since I'm going with a 3.4 and everything already exists for it. To that point, I could literally even just go with the ECM and harness from an F-body. But I'm really sticking firm to my goal about trying to keep the car looking stock. I have a few cars that I'm restoring / building... and will be, and the Fiero... literally the one I have right now in storage, was my very first car. For a long time I thought about doing all kinds of things to it, but I've wanted to bring everything back to stock, including removing the side scoop and replacing it with the little grill. Doesn't mean I don't want more power, but when I lift the engine compartment, I want it to essentially look about as stock as possible, though my goal is to clean up a few things. I'm going to keep the EGR, but with the new ECM I'm going to eliminate it, so I'll just put a blocking plate between the EGR and EGR tube... or might even plane and weld a plug into the EGR. But yeah... I plan to keep the distributor.

Here's a thought that I had though... I am thinking about possibly using the 3.4's crank sensor wheel. I can do this with the new ECM I'm running, and while it will control ignition, I'm going to use the MSD-6EFI to control the spark... my goal is going to figure out where I'm going to hide it.

Another thing I want to possibly do is look to re-routing the wiring harnesses. The idea of suspending the engine harness directly above the belts seems idiotic to me. I think I saw, either La Fiera or zkhennings, one of you had re-routed the entire harness off the backside of the engine, and then ran it along the firewall to get it out of the way. This is probably what I'm going to do to.

Anyway, question I have is... can I use the crank sensor with my ECM, while also having the distributor and coil being controlled by the MSD-6EFI. I'm not sure, it lists an either or... but that could simply be because most people wouldn't have both.
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