3500 top-end in 95 f-body

[ForcedFirebird]

dropping the engine would be a good investment with the gains in handling that you would also get... if you could pull it back any further it would also help but there are limits to everything as im sure you are aware of

Driver was able to get a 3400 in his 4th gen fbody by using a tubular k member

i just hope your not looking to get the n/a numbers and the boosted numbers out of the same setup... honestly, a high comp setup would be fine with a turbo but not anywhere near 20psi

Almost the same setup. I'm planning on leaving the 3.4 pistons while N/A (about 11:1CR), and 3400 pistons when it get re-boosted (about 8.8:1CR)

[El_Diablo]

dropping the engine would be a good investment with the gains in handling that you would also get... if you could pull it back any further it would also help but there are limits to everything as im sure you are aware of

i just hope your not looking to get the n/a numbers and the boosted numbers out of the same setup... honestly, a high comp setup would be fine with a turbo but not anywhere near 20psi

[ForcedFirebird]

forcedfirebird -- you wont have the same issue that myself and driver_10 might have, because you have a third gen and the engine not only sits a little bit differently, but your height limiting factor is in the bottom of the hood, which can be changed by going to a SS style or cowl induction.

the limiting factor in the 4th gens is the cowl, or area the windshield sits on top of. the only way to change the height of that, would be to notch or cut the windshield and then move things around -- a much more difficult task than just changing the hood.

While driver_10 used a full 3400 engine and custom motor mounts to drop the engine - I used stock motor mounts and only the 3100 and then 3400 topend, so my motor sits in the stock 3.4 location. WITH THIS SETUP - i have 1/8" clearance between the top of the 3400 plenum with the "3400 sfi" shaved off (had to use my rotozip) and the underside of the cowl - "top of the engine bay"

the 3500 plenum is the same height as the 3400 plenum - WITH THE "3400 SFI" letters on top. when i tried putting the 3400 plenum in before i removed the lettering on top, it scraped the cowl. it would have meant that the motor would have been directly tied to the rest of the car, and i would have negated any effects of motor mounts (think solid mounts...rattling your teeth out, etc).

the height is different - because i am measuring differently than driver_10 is. if you make custom motor mounts (which is something im considering having done) - i could use any plenum i wanted to. the other limiting factor to me right now, is that im using the stock k-member.

there are a lot of differences between everyone else's "3400 setup" and mine - being that i did this myself, when everyone said it wouldnt work, and i had to invent everything as i went, i used what i had on a VERY limited budget.

consequently, i am using the stock 3.4 tune and because of the cam i have in there now (its always run a little off) the engine is just dumping fuel into the motor. i currently have a 10.5:1 Air to Fuel Ratio (rich) running the car and i probably get around 8 mpg. (im not kidding).

on my last dyno - 3400 heads and aftermarket cam - i recorded 184rwhp / 212rwtq. if i could tune (working on it), those numbers would go up... something to look forward to i think lol.

Hey Russel! Yes since this origional post, I have learned the amount of room the 4th gens have. I was under the impression that you guys had a 3 piece manifold like the earlier MPFI's, but since discovered that you have the UIM and MIM molded into one piece.

BUT, as Driver mentioned earlier in this thread, he managed to drop the motor by 1.5", and that should give more than adequite room to do a 3500 upper end swap.

I'm hoping to get 250hp N/A, and put about 20psi on it . With a MegaSquirt tune, custom headers, LS6 springs, ported/polished, 75mm TB, and 1.7 rockers riding on a 262 cam (maybe 272 if lift isn't too excessive), I'm thinking it is possible. At 20psi, I should be able to get over 500hp. The most I have seen out of a 660 is 475hp, and I want to push the limits of the little beast.

The next question, is how am I going to get enough traction?

-John

"3.4/3500 RWD Pioneer"

[94Camaro]

forcedfirebird -- you wont have the same issue that myself and driver_10 might have, because you have a third gen and the engine not only sits a little bit differently, but your height limiting factor is in the bottom of the hood, which can be changed by going to a SS style or cowl induction.

the limiting factor in the 4th gens is the cowl, or area the windshield sits on top of. the only way to change the height of that, would be to notch or cut the windshield and then move things around -- a much more difficult task than just changing the hood.

While driver_10 used a full 3400 engine and custom motor mounts to drop the engine - I used stock motor mounts and only the 3100 and then 3400 topend, so my motor sits in the stock 3.4 location. WITH THIS SETUP - i have 1/8" clearance between the top of the 3400 plenum with the "3400 sfi" shaved off (had to use my rotozip) and the underside of the cowl - "top of the engine bay"

the 3500 plenum is the same height as the 3400 plenum - WITH THE "3400 SFI" letters on top. when i tried putting the 3400 plenum in before i removed the lettering on top, it scraped the cowl. it would have meant that the motor would have been directly tied to the rest of the car, and i would have negated any effects of motor mounts (think solid mounts...rattling your teeth out, etc).

the height is different - because i am measuring differently than driver_10 is. if you make custom motor mounts (which is something im considering having done) - i could use any plenum i wanted to. the other limiting factor to me right now, is that im using the stock k-member.

there are a lot of differences between everyone else's "3400 setup" and mine - being that i did this myself, when everyone said it wouldnt work, and i had to invent everything as i went, i used what i had on a VERY limited budget.

consequently, i am using the stock 3.4 tune and because of the cam i have in there now (its always run a little off) the engine is just dumping fuel into the motor. i currently have a 10.5:1 Air to Fuel Ratio (rich) running the car and i probably get around 8 mpg. (im not kidding).

on my last dyno - 3400 heads and aftermarket cam - i recorded 184rwhp / 212rwtq. if i could tune (working on it), those numbers would go up... something to look forward to i think lol.

[SappySE107]

I believe 1.5" will give you the room to use the 3500 upper. If you aren't doing anything soon, you will have time to see some results on boost porting. I have some setups I am working on and will have it all available soon 3400 vs 3500 top end under boost conditions is less cut and dry like I am seeing the NA setups.

[ForcedFirebird]

Whatever the brake booster takes up. I don't remember what I measured it to but I dont have a camaro with a 3400 to drop it in and test fit.

The booster port was the difference I saw. Driver's 3400 sits 1.5" or so lower than the 3.4 IIRC, that would give him 3" above the MPFI/SFI top end.

I can see a 3x00 swap in my distant future

[SappySE107]

Whatever the brake booster takes up. I don't remember what I measured it to but I dont have a camaro with a 3400 to drop it in and test fit.

[ForcedFirebird]

no, higher than the 3400.

Not by much. What kind of measurement difference did you guys come up with?

[SappySE107]

no, higher than the 3400.

[ForcedFirebird]

The 3500 sticks up higher and unless you lower the entire engine more

Higher than the Gen1 intake? The 3400 is a full 1.5" or more lower than the 3.1/2.8, unsure about the 3.4.

[ForcedFirebird]

Driver wanted to know about the 3500 heads bolted on the 3400.

No, I'm not that drunk but don't want to have a mishap either. I didn't flip the 3400 heads over and have a look-see comp to the 3500's, but I have seen your flow sheets and KNOW the difference . I just took a quick look, grabbed a couple of bolts and set them together to take pics. I can't wait to get some gaskets to match to, any suggestions?

It's just a visual thing, I really didn't know the big difference between the iron and aluminum heads, UNTIL I HAD A PAIR IN MY HANDS!!! Anybody who knows anything about anything, could tell the advances in design, but not everybody cares....

[SappySE107]

The 3500 sticks up higher and unless you lower the entire engine more, it won't clear your hood. Russ measured all that before. The 3500 heads are lot different and we have pictures and flowsheets for them. I bet when you sober up and actually look at the heads you will see some updates to the design.

[ForcedFirebird]

If your running a turbo, the turbo is gonna do most of the work so I dont think the head change would make a big difference. About as much as a a good port, polish, match, and valve job on the 3400 heads. I've never done any of this myself, but it just makes sense.

HUH?


Hey Driver 10!!! The 3500 will fit anyewhere a 3400 fits ...







Although, I have had a few beers tonight and din't want to go and handling the heads too much , but the 3500 heads don't look that advantagious to the 3400. It seems the 3500 upper end has a much better UIM design and larger chambers, but until I sober up a bit, I'm not going to do any measurements/comparisons. However, the question about height has been answered, *thank-you, thank-you very-much*, lmao


EDIT: Please note the accesory bracket bolt holes, they differ between the 3400/3500...

[FiredUpZ28]

If your running a turbo, the turbo is gonna do most of the work so I dont think the head change would make a big difference. About as much as a a good port, polish, match, and valve job on the 3400 heads. I've never done any of this myself, but it just makes sense.

[SappySE107]

Stock 3400 had an auto, not a manual. The stock gen 3 cam is more aggressive than a stock 3.4 iron head cam. Russ is using an aftermarket cam now and really needs some tuning. His results are good, but they certainly could be better with a tune. He was and probably still is running the stock 3.4 chip