I lot of us have been down this road before. Can improvements be made? Sure, but don't expect any substantial gains. For the time, effort, and money, at least change the block to a 3.4 if you want to maintain the stock appearance. I did almost everything you could to the 2.8 and while it was better, I wish I would have just swapped the motor.
I get the idea on Pennocks that people are generally disappointed with their cars and this disappointment is endured for decades. Maybe people just cant get rid of them because they don't rust too bad.
I get the idea on Pennocks that people are generally disappointed with their cars and this disappointment is endured for decades. Maybe people just cant get rid of them because they don't rust too bad.
Or the folks who are pleased with their cars don't chime in with engine upgrade suggestions
porting does help, make sure not to remove the vane in the ports. Porting not only increases flow, but the mirror polish on the combustion chambers and exhaust really does prevent carbon build up. It is not just about hogging it out, but on port reshaping and design. Read up on it, not on this forum though, no offence guys, there are much better guides out there.
Now as far as the hole saw idea doing a perfect port job, I call BS, I have ported ALOT of manifolds and there is just no way a hole saw will do a perfect job, it may remove most of it, but no way it can hit the edges, also the Herb Adams reported an 8HP gain on the manifold porting.
If you want, do what you want. I say to stay focused. Don't get discouraged. Maybe the swaps make for a faster, better machine, but my Fiero came off the assembly line with a 2.8, and until the block cracks or disintegrates, that's what it will have in it. I don't mind spending the time tweaking the original design to coach more performance out of it. I haven't spent anywhere close to what it costs to swap a motor and am completely satisfied with the results. With all the porting and taking your time setting timing correctly, you'll have power on demand....it won't be no sissy setup. Of course, please don't get me wrong. Some day, when i blow up my 2.8, I'll go for the 3800 sc option (or whatever the engine size is, i forget), because that setup is a corvette killer.....I'm just sayin.....
After porting my heads and putting on proper headers and exhaust, my 3.4 with the Fiero intake ran better than my 4.9. When I switched to a Trueleo intake, I killed my velocity and lost the TPI effect and made less power as mentioned earlier.
With my 4.9, I had the Allante intake and Bosch Design 3 injectors from a Lincoln Mark 8 or whatever it's called.
My 4.9 put down 175rwhp/275 ft*lbs. Peak at 4100 rpm...IIRC My 3.4 using 3400 block and cam and Fiero intake put down 187rwhp/249 ft*lbs. Peak at 4100 rpm... After switching to the Trueleo intake: 172 rwhp/ 208 ft*lbs. Peak at 4900 rpm... And this is with the stock 3400 cam.
I'll take a 3.4 done right over a 4.9 any day. If I had a 4cyl, then and only then I'd consider the 4.9 as a viable upgrade to that if it could be done cheap enough. ...and yes, I might switch back to the Fiero (ported) intake, now DAWG-modded, if my compression test checks out good...
[This message has been edited by lou_dias (edited 08-06-2014).]
After porting my heads and putting on proper headers and exhaust, my 3.4 with the Fiero intake ran better than my 4.9. When I switched to a Trueleo intake, I killed my velocity and lost the TPI effect and made less power as mentioned earlier.
With my 4.9, I had the Allante intake and Bosch Design 3 injectors from a Lincoln Mark 8 or whatever it's called.
My 4.9 put down 175rwhp/275 ft*lbs. Peak at 4100 rpm...IIRC My 3.4 using 3400 block and cam and Fiero intake put down 187rwhp/249 ft*lbs. Peak at 4100 rpm... After switching to the Trueleo intake: 172 rwhp/ 208 ft*lbs. Peak at 4900 rpm... And this is with the stock 3400 cam.
I'll take a 3.4 done right over a 4.9 any day. If I had a 4cyl, then and only then I'd consider the 4.9 as a viable upgrade to that if it could be done cheap enough. ...and yes, I might switch back to the Fiero (ported) intake, now DAWG-modded, if my compression test checks out good...
Great information! I really want a 3.4 swap and just make it look absolutely amazing, port it, polish it. I don't understand the mentality that people feel like a V8 is the answer for power. I own a 91' Seville with the 4.9 and it's not impressive at all, plus the gas mileage is like 18MPG when im lucky. Have you since tried an upgraded cam with the 3.4?
Originally posted by zzzhuh: Great information! I really want a 3.4 swap and just make it look absolutely amazing, port it, polish it. I don't understand the mentality that people feel like a V8 is the answer for power. I own a 91' Seville with the 4.9 and it's not impressive at all, plus the gas mileage is like 18MPG when im lucky. Have you since tried an upgraded cam with the 3.4?
A 91 Seville weighs about 700 lbs more than an 86 Fiero GT. It's also got a flat front. The 4.9 in the Fiero will get quite a bit better MPG than in the Seville.
The 3.4 is a good starter swap to go with, but aside from better oiling and a little more power in stock form, you're not really going to get much out of it. It's a downward spiral after 4000 RPM. What I don't understand is the mentality of somehow finding significant meaning in a peak HP number as a measure of performance. What really matters, is area under the curve for torque. HP is simply a mathematical function of torque. If you're thinking of choosing between a heavily built 3.4, or a stock 4.9, the 4.9 will give you better performance, and will probably get the same MPG as a built 3.4, especially if you're also swapping up to a 5 or 6 speed speed manual trans instead of the big heavy 4t80 auto.
Heck, here are a couple dyno charts that are from lou_dias, which prove the point.
3.4 with Trueleo:
4.9:
Unfortunately, they aren't over the same RPM range, so it's a little tough to say how low the 3.4 starts making power, as the graph starts around 3200 RPM, while the 4.9 graph starts at around 1900. Even only comparing the 3000+ RPM values though, you can see the 4.9 is already making about 70 more ft-lbs at 3200 RPM, and stays over 200 ft-lbs until about 4500 RPM. The 3.4 starts really dropping off around 4200, but manages to keep squeezing out a little bit of torque up to 5252 RPM where the HP/torque lines meet. The 4.9 smacks into a wall around 4700 RPM, but keeps the torque up over 200 ft-lbs for about 2500 RPM, while the 3.4 isn't even making it over 200, and from the dyno, doesn't look like it even starts making its power until 3000 RPM.
going from a 2.8 to a built 3.4 is far easier than going to a 4.9.
Here's my dyno with the Fiero intake. It only didn't make power past 4300 because I still had the neck restriction. Also the injectors weren't calibrated right which is why I went real rich down low. I never tuned it past this dyno because I ended up, regrettably in retrospect, switching to the Trueleo intake and doing a '7730 conversion which resulted in my loss of power.
It should have peaked around 4900 like the Trueleo intake did but with even more power.
[This message has been edited by lou_dias (edited 08-06-2014).]
going from a 2.8 to a built 3.4 is far easier than going to a 4.9.
Here's my dyno with the Fiero intake. It only didn't make power past 4300 because I still had the neck restriction. Also the injectors weren't calibrated right which is why I went real rich down low. I never tuned it past this dyno because I ended up, regrettably in retrospect, switching to the Trueleo intake and doing a '7730 conversion which resulted in my loss of power.
It should have peaked around 4900 like the Trueleo intake did but with even more power.
Are the numbers in this dyno chart corrected to be the crank output, versus rear wheel output?
Originally posted by dobey: Are the numbers in this dyno chart corrected to be the crank output, versus rear wheel output?
Those were rear wheel #'s on a Mustang dyno known to be 5% lower that the other dyno you quoted me on. If I was on that Mike Dez Racing dyno, it would have read 196rwhp...
Because of my excessive porting with no cam change and big intake, I lost the TPI effect...like Will said can happen on the previous page... I am seriously considering reverting back to that old ported Fiero intake which has since been DAWG-modded to allow it to breathe past 4300 rpm...
...atleast until I build a new motor with a much bigger cam...
[This message has been edited by lou_dias (edited 08-06-2014).]
Originally posted by zzzhuh: I don't understand the mentality that people feel like a V8 is the answer for power.
Thoughts: Alot of people choose V8s for the sound, some choose old style V8s for simplicity, though with 187 as a perceived good hp number, its easy to get a V8 with more than that.
[This message has been edited by 2.5 (edited 08-06-2014).]
Now as far as the hole saw idea doing a perfect port job, I call BS, I have ported ALOT of manifolds and there is just no way a hole saw will do a perfect job, it may remove most of it, but no way it can hit the edges...
You not happy with my use of the term "perfect" or what?
When the hole saw fits each exhaust manifold port perfectly (no slop, absolutely tight), and removes all metal in its path further into the exhaust log, I think I can be excused in suggesting it does a "perfect" job.
I'm sorry if you've spent hours and hours and hours porting exhaust manifolds, but if you honestly believe you gained a whole lot more performance with your sacrifice... fine.
My buddy has a Hole Saw kit (similar to what's pictured below) which includes a cutter which is the exact same size as the inside of the manifold ports.
You may not wish to hear this, but it takes about ten seconds per port to do a perfect job! I'm not kidding. I'm surprised more people don't use this method.
Yeah as the manifolds curve in you will not get to that with a hole saw, thus it will disrupt air flow, btw I can do both manifolds in about a 1/2 hr. So no, the hole saw is not "perfect" it is "good enough" for most.
Edit to add: It is a good idea, just not for me.
[This message has been edited by sardonyx247 (edited 08-06-2014).]
Yeah as the manifolds curve in you will not get to that with a hole saw, thus it will disrupt air flow...
Not really sure what you're referring to. Here's a couple images from the forum of the blockages in these exhaust manifolds. The hole saw removes this completely.... in ten seconds or less. And because using the hole saw gives precise control over what is being cut, it doesn't remove more than is necessary. So there was no need (with my manifolds) to weld the other side of the flange. No cracks, no leaks, works great.
[This message has been edited by Patrick (edited 08-06-2014).]
Originally posted by 2.5: Thoughts: Alot of people choose V8s for the sound, some choose old style V8s for simplicity, though with 187 as a perceived good hp number, its easy to get a V8 with more than that.
Yeah but getting the V8 into the Fiero IS the problem. When I was making 249 ft*lbs, I did 2 clutch dumps at the track and both times I snapped an axle and the 2nd time it snapped the bearing with it. So the one "benefit" of making less power is I don't have to keep buying axles from Archie... (I'm running the F40 6 speed...) As a guy who races 5 times a year with multiple clutch dumps each time, that's pretty important. Now granted, that's before I shaved the face of the spindles off .3" to improve the spline contact on my HELD rear bump-steer correction arm...but I digress...
Yeah but getting the V8 into the Fiero IS the problem. When I was making 249 ft*lbs, I did 2 clutch dumps at the track and both times I snapped an axle and the 2nd time it snapped the bearing with it. So the one "benefit" of making less power is I don't have to keep buying axles from Archie... (I'm running the F40 6 speed...) As a guy who races 5 times a year with multiple clutch dumps each time, that's pretty important. Now granted, that's before I shaved the face of the spindles off .3" to improve the spline contact on my HELD rear bump-steer correction arm...but I digress...
I'm a little unclear on what you mean with this post exactly. Are you trying to say the V8 is bad because you were making enough power with the V6 to break an axle when dumping the clutch at the track?
A 91 Seville weighs about 700 lbs more than an 86 Fiero GT. It's also got a flat front. The 4.9 in the Fiero will get quite a bit better MPG than in the Seville.
Not sure what you meant by 'flat' but figured I would take some pictures to make sure were on the same page.
From a front view, I can understand how you might perceive this as flat.
But looking at this from a side view, it actually comes to a >.
As far as the 3.4 vs 4.9 you've also got to take into consideration about the price for power. From what I can gather, a 4.9L swap can cost from $2,000 to $3,000 (3.8SC range.) By comparison, the 3.4 can be done for far less ($900-$1200) and still has plenty of after market support that the 4.9L lacks. I do like the look of the 4.9L, especially the way 'Neils88' did his with black a yellow.
IMO I think having a stock look is rather hard to beat. To make people think that a 2.8L stock fiero just beat there ricer is rather fun and entertaining.
Thoughts: Alot of people choose V8s for the sound, some choose old style V8s for simplicity, though with 187 as a perceived good hp number, its easy to get a V8 with more than that.
I can understand that people would enjoy the V 8 rumble, and to be fair it is hard to beat. As far as 'simplicity' though, the 4.9L isn't necessary a carbureted chevy 350.
Originally posted by dobey: I'm a little unclear on what you mean with this post exactly. Are you trying to say the V8 is bad because you were making enough power with the V6 to break an axle when dumping the clutch at the track?
Originally posted by lou_dias: yes, and on an oval track, power isn't everything
On a straight track, power isn't everything. You need the right suspension, tires, and steering setup for it too.
But saying the 4.9 is hard to put in a Fiero because you've spend $3000 building a 3.4 that makes almost as much power, is a bit off. The 4.9 is the easiest V8 swap there is for the Fiero, and if you really want to run a carb instead of the EFI, it's easy enough to do that. It's certainly cheaper than building a 3.4 to make almost, but not quite, the same power, too.
Originally posted by zzzhuh: Not sure what you meant by 'flat' but figured I would take some pictures to make sure were on the same page. From a front view, I can understand how you might perceive this as flat. But looking at this from a side view, it actually comes to a >.
The Fiero coupe is a wedge shape. The Seville is far from it. The later body style when they went to the Northstar, is much better aerodynamically. The 91 Seville has a front that's almost as bad as the 91 S-10 for aerodynamics. The roofline at the rear is also not so great. Plus the weight difference. MPG in a car is a result of many more things than just the engine and how many cylinders it has. Even in the Cadillac though, if you're only getting an 18 MPG average out of it where you live, I'd be looking for what's wrong there, given your 30 MPG claims of a stock Fiero GT in your other thread, and that 18 for the Seville is the EPA estimate for combined MPG.
quote
Originally posted by zzzhuh: As far as the 3.4 vs 4.9 you've also got to take into consideration about the price for power. From what I can gather, a 4.9L swap can cost from $2,000 to $3,000 (3.8SC range.) By comparison, the 3.4 can be done for far less ($900-$1200) and still has plenty of after market support that the 4.9L lacks. I do like the look of the 4.9L, especially the way 'Neils88' did his with black a yellow.
Are you talking about cost of doing the swap yourself, or paying someone to do it? Doing the swap yourself, it should be doable for around $1200. The 4.9 can be picked up pretty cheap, it will bolt straight up to any Fiero transmission, and the wiring isn't that bad since it's an OBD-I engine, or you can even go carbed if you really want to. If you want to get that amount of power out of the 3.4, you're going to have to spend $3000+ to get it done. A few aftermarket bolt-ons isn't going to get you there.
quote
Originally posted by zzzhuh: IMO I think having a stock look is rather hard to beat. To make people think that a 2.8L stock fiero just beat there ricer is rather fun and entertaining.
What are you calling a ricer exactly? The stock 2.8 will pick up and go pretty good in the Fiero as it is. A 3.4 is also pretty far from stock, even with the stock intake. You could just do a stealth install of nitrous, too. A properly built and tuned Japanese car will probably still pull away from you easily enough, even with a built and tuned 3.4.
But yeah, if you want a properly fast car with good MPG, it's best to stay away from the 3.4 and the 4.9 both, and just go for a 3800. Save your money if that's what you want anyway, and do it when you can, instead of spending money on a 3.4 swap right now; especially if your car is running fine.
To Patrick, the side you can't see in the pic usally has a little lip on it, any lip causes a stumble on flow, but just to do it I will try the hole saw method next time I port a manifold to see how it all comes out, and I never once welded a manifold no problems yet, the only time I had the flange come off was when I planned it flat, the weld was too high, not all manifold are created equal that is for sure, I compared 20 of them and they are ALL different.
To every one else a 3.4 can be done under $600 no prob, that is $450 for an engine and then gaskets and fluids. And looks better than ANY engine swap as it says "FIERO" you just cant beat that, power yes, but to say FIERO that is just classic. :P but the 4.9 is the next cheapest swap.
To the OP here is a good guide on porting, it is for a SBC but the same rules apply http://www.lcengineering.co...dard%20Abrasives.pdf They sell a good kit, after you have practice, get some good carbide bits, they cut faster and don't clog as much. But get the hang of it first as they do cut faster. When it comes to the intakes get an aluminum cutting bit, make sure you ARE GOOD at porting first as they cut REALLY fast, very easy to cut a hole, and aluminum clogs bits fast but not the aluminum cutting bits. Best to get a spare head and go to town on it so you get the hang of it.
On a straight track, power isn't everything. You need the right suspension, tires, and steering setup for it too.
But saying the 4.9 is hard to put in a Fiero because you've spend $3000 building a 3.4 that makes almost as much power, is a bit off. The 4.9 is the easiest V8 swap there is for the Fiero, and if you really want to run a carb instead of the EFI, it's easy enough to do that. It's certainly cheaper than building a 3.4 to make almost, but not quite, the same power, too.
We're getting off-topic here. Let me just say that the power band of the 3.4 can be built to be much wider than the 4.9 very cheaply, hence the "area under the curve" does favor it. Just slapping in an HT272 cam with a mild port job is enough to out-run a 4.9 so we aren't talking big dollars here. They both require exhaust work and both my former 4.9 and 3.4 have 2.5" exhausts. Oreif got 205 rwhp from a HT272 cam with a Trueleo intake and 62mm TB and ported stock exhaust.
[This message has been edited by lou_dias (edited 08-07-2014).]
I can understand that people would enjoy the V 8 rumble, and to be fair it is hard to beat. As far as 'simplicity' though, the 4.9L isn't necessary a carbureted chevy 350.
Personally I wouldnt choose the 4.9, but its easier to install than some others is wy it is chosen by some.
[This message has been edited by 2.5 (edited 08-07-2014).]
Yeah but getting the V8 into the Fiero IS the problem. When I was making 249 ft*lbs, I did 2 clutch dumps at the track and both times I snapped an axle and the 2nd time it snapped the bearing with it. So the one "benefit" of making less power is I don't have to keep buying axles from Archie... (I'm running the F40 6 speed...) As a guy who races 5 times a year with multiple clutch dumps each time, that's pretty important. Now granted, that's before I shaved the face of the spindles off .3" to improve the spline contact on my HELD rear bump-steer correction arm...but I digress...
If you fed the clutch instead of dropping it, you wouldn't have this problem.
Originally posted by sardonyx247: To every one else a 3.4 can be done under $600 no prob, that is $450 for an engine and then gaskets and fluids. And looks better than ANY engine swap as it says "FIERO" you just cant beat that, power yes, but to say FIERO that is just classic. :P but the 4.9 is the next cheapest swap.
The 85-86 V6 just had a sticker on top of the intake. I can put that same sticker on any engine.
1.The Seville is far from it. The later body style when they went to the Northstar, is much better aerodynamically. The 91 Seville has a front that's almost as bad as the 91 S-10 for aerodynamics. MPG in a car is a result of many more things than just the engine and how many cylinders it has.
2.I'd be looking for what's wrong there, given your 30 MPG claims of a stock Fiero GT in your other thread, and that 18 for the Seville is the EPA estimate for combined MPG.
3.if you want a properly fast car with good MPG, it's best to stay away from the 3.4 and the 4.9 both, and just go for a 3800.
.
1.Actually, the front fascia of the two designs are very similar. The body on a 91 vs a 93 (northstar introduction) specs. are as stated below.
1991- Width: 72.0 in. Height: 53.2 in. Length: 190.8 in. Curb weight: 3512 lbs.
1993- Width: 76.4 in. Height: 54.0 in. Length: 204.4 in. Curb weight: 3648 lbs.
Judging by your words, the 91 is actually more efficient than the later design. However I do prefer the look of the later years, especially 98-04.
2.My seville does have 194,000 miles on it, so I can't expect it to be as efficient as when it was new. BTW, im still getting those number's for the fiero
3.I agree, I've read several places that doing a 3.4L swap isn't worth the money if the 2.8 is working just fine. I want to save up for a 3.8SC but it's the idea of having more power that get's me giddy.
[This message has been edited by zzzhuh (edited 08-07-2014).]
Originally posted by Will: If you fed the clutch instead of dropping it, you wouldn't have this problem.
With a getrag, even from a rolling start, the tires can spin with a 4.9. Its even worse coming out of a corner. If I have to feather then I'm introducing losses. With the V6, I can put a higher % of my power to the ground. Power is great until you have too much. What I need is more lift out of my 3.4 so that I can pull harder on the back-straightaway at the oval track.
This is my launch, you can already see the car squatting:
This is a split second later:
Above is my launch against most RWD cars. With the 4.9, Mustangs have kept up with me on the launch. You can talk theory but practice tells me otherwise.
