3.4 L32 V6/60... questions... compared to L44 (Page 4/9)
La fiera MAY 14, 11:19 PM
Removed because It is not my thread, sorry T/A!

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

82-T/A [At Work] MAY 16, 09:28 AM

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 ...
zkhennings MAY 16, 12:40 PM

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.
La fiera MAY 16, 08:21 PM

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
lou_dias MAY 16, 09:11 PM
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).]

La fiera MAY 16, 09:54 PM

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?
zkhennings MAY 16, 10:17 PM
No worries I wasn’t taking anything personally, there’s just pros and cons to every choice when it comes to making more power.
lou_dias MAY 17, 10:00 AM
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.
zkhennings MAY 17, 11:41 AM
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.
82-T/A [At Work] MAY 17, 03:21 PM

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.