Hey guys, I'm on vacation in San Fransico and just now found a internet connection for my laptop. Apparently my previous thread was closed. So for those of you that were interested in the constructive tech side of the post I apologize. For those that were responsible for the thread being closed by your unconstructive bickering, please take it to a non-tech post, it was amusing at first 1 or 2 posts but then it went way too far. So please keep it out of the tech posts.

Anyways on to the original topic of conversation. I considered using a 3.1 in my very first post, and then I looked at using FWD heads, and also a GEN II 3.8, etc. I know I can make it work, but to my knowledge I can't find anyone that has done a 3.4 DOHC transplant into an F-body, let alone turbocharged it.

I've researched the DOHC 3.4 and found that when GM first designed it they made 280hp emissions legal at 7000 RPM. Apparently this engine was ready for production at these numbers, which means that because they had to warranty it and mass produce it at these numbers, the engine was reliable and driveable at this configuration. From what I can find this engine had the same specs that the mass produced W-body had. If 280 hp could be produced at 9.5:1 compression, drop the compression to 8.5:1 and add a turbocharger at 12lbs of boost this would realize over 13:1 compression at full boost. On a 24V motor that could produce some serious HP. There are 300ZX's, 3000GT VR4's, and Supras makeing 700hp on 3.0L DOHC motors. I haven't seen any pushrod V6's making that much HP and still being street legal and driveable.

Now I'm still researching all this so some of my information could be flawed, and if it is please let me know. I figure I still have another few weeks of research ahead of me before I start the project. Plus I'm stil waiting to get the title from the guy I bought the car from b4 I put any $ into it. Otherwise know my luck I'd have the car finished and makeing 700hp and he still has the title to it.

BTW Pat, I measured the engine compartment, and the engine will fit with room to spare. Not much, but still enough.

Step 1 is to purchase the engine and install it and make it driveable, then I'll work on the turbo setup.

Fact/Opinions are welcomed provided their constructive.

Thanks guys

Brian

 

Well first off, I am assuming your going to intercool this car?
If not you may (and probably will) run into a lot of knock with a 13:1 compression ratio.

As well I think It would just be impressive if you found a way to install the 3.4 DOHC in the F-body. If you lead the way many more would try.

Good luck with finding the engine and installing it.
Keep us posted.

 

Well, being a Fwd aluminum engine, you will possibly reduce the weight also. Is this going to be automatic or manual??

I am having problems finding a place/equipment to edit the prom's on the "cross" ecms that look like ODB2, but are still ODB1. You will need to have that done for it to run properly for the turbo issue.


If you happen to go with a 3.8l from the 4th gens, theirs a guy somewhere that installed a ati procharger.

I also have a link somewhere to a guy who claims to have turboed a 94 3.4l engine like we use for the block swaps.

Don't forget custom headers, y-pipe, catback.

 

A real smart buddy all into engines, there is a chart somewhere that give the equasion to find out which motors have the highest rpms, closest to 0 wins

the 2.8 is the closest with a possiable 14000 rpm's, if you could get the parts.

some forumla to do with bore n stroke, like a 355 is a de stroked 383 for more rpms or one of them engines is like that.


just think about a 2.8 that wound up to 10,000 let alone 14,000 rpms. dont need no turbo and wont even need more than 3 gears

 

Yes I'm definately intercooling the car. I'm going to build a custom ram air hood that instead of ramming air into the engine it will ram it through an intercooler. If necessary I might engineer a water injection system or 7th fuel injector that kicks in via a pressure switch (similar to what is done on the turbo daytona's http://www.thedodgegarage.com/turbo_extrainj.html) to take care of detonation. That is of course only if I can't get an ECM to take care of the fuel enrichment for me. If I can't get a GM ECM that is OBD-I and can handle boost on a distributorless ignition system I might go with an aftermarket ECM, but stick with the GM FI sysem.

The car will be automatic. The stock trans is automatic, and I don't believe a T5 can handle the Tq I'm hoping to extract from this beast nor do I want to spend the $ on a MT that will handle the tq. The DOHC aluminum motor weighs around 400lbs so there isn't a real big difference there, but considering the additional weight from the 24v heads it helps that its not cast iron. The exhaust will be true dual (don't ask how I haven't figured that out yet.) and I'll fab the headers myself (thats true hotrodding ).

Gumby, the stock yellowline is 6500 and the redline is 7000 on these DOHC's so I shouldn't have to do too much work to the bottom end except for lower compression forged pistons. To tach up that high on a production engine means the crank and bearings must be pretty tough. I revved my 305 up to 6500-7000 on accident b4 without it blowing up (ironically it was overheating that finally killed it.. but then came the 350) and the redline on that was 5500, so the 3.4 should be able to handle 8500 with some valvetrane work (I think... probably... maybe... I hope).

Thanks for the feedback, keep it coming the more questions I have to research the answers to the better engineered this is going to be. I will be putting up a how to website on this so others can do it to... provided I get everything to work that is.

Brian

 

Check this out i kinda hijacked it from some other dude at the v6 forums 3.4 dohc hope it helps i just picked up a 7749 ecm and a 2 bar map good for 15 psi of boost from the junkyard today so if i want to put a turbo on next year i can. If you do this you have to do alot of reading and spend shat loads of time working on it plus i don't know if the engine will fit between the strut towers? Good luck and if it works i might do it to for now i might get a roller cam 3.4 out of a ventura mini van and use that for my turbo platform.

 

im gonna make a sigestion here. use a grand prix turbo motor. use a standard 2.8 3.1 block for rwd. dump all the guts heads intake pistons cam etc onto the RWD block. or get a 3.4 block and use the same guts from the 3.1 GTP engine and get custom pistons.

you end up with DIS, boost code $8f in a 1227727 ecm becuase itll be coming form the GPT.

then it all pretty straight forward the block will bolt right up. no mods needed. the hardware already exists. and the software and electronics could be swapped from the GPT or a LUmina and then add a circut to the ecm wiring pin C1 batt for the lumina harness its 99% the same. then just use all the GPT hardware. you in business the block are the same except for the mounting tabs. this is the easiet way to go.

need help just email.

 

I would go to that Turbo GNX page that does the Turbo TA conversion on Firebirds and Trans-AMs and go that way. You can then put additional cash into that setup and get into the low 13's. Just a suggestion.

 

to keep the same trans and all you have to stay in the 60* block family. thats rulse out alot of engines. also its cheaper to stay with the same trans etc.

 

Well, I think I've decided on an alternative engine. I don't have the $$ right now to go with a 3.4 DOHC. I do however have a couple of 4.3's lying around that don't have a home. I have a CPI intake manifold (plenum and runners are all built into the intake) I might try to rig the 4.3 with the CPI to the Camaro's existing MPFI computer and wiring harness. I think it'll take some creative engineering, but I believe I can make more HP by turbocharging a bigger displacement engine. As much as I want to build a high-tech high-revving turbo charged V6, I don't have $800 to buy the 3.4 DOHC motor, and that doesn't even include the price of the turbo and materials for fabricating headers, intake, etc. I do however have the 4.3 and a 90* trans for it and I think I can canibalize the TPI, MPFI, and CPI systems I have collecting dust to make a working port FI system for this. I'm gonna check some of the SYTY sites and see if anyone there has left over intakes, plenums, etc to sell. If I can get it all cheap I may engineer a 4.3 Turbo Camaro. It doesn't sound as cool as a DOHC 3.4 but at least I can afford it with out selling any kidneys. Just have to get a 749 ECM, repin it and figure out how I'm gonna make the induction system work.

If anyone has any thoughts let me know...

Thanx
Brian

 

Boost and 13:1 CR LMFAO!! :sillylol: Try it, you MIGHT get up the block..

 

I think he said realized compression, not his mechanical or whatever you wanna call it CR. I don't think 13:1 on an intercooled car is that far out of line. Course, you already know that

 

To clear that up, AmorgetRS is right. The engine's actual CR before boost will be as close to 8.5:1 CR as possible while keeping a .045 quench. The 13:1 is what the engine will realize at full boost of about 8psi. With 93 octane intercooling and richening up the mixture along with a close quench there should be no problem avoiding detonation. I believe the 749 computer has a built in boost retard feature I can use to retard the timing at certain levels of boost.

I have a 350 in my other Camaro and before it went to the machine shop (which is where it is now) ran rather well at 10psi of boost on cast (thats right CAST) pistons. This engine had an 8:1 CR and ran great. The only reason I tore the motor down was because I wanted to raise the CR to 8.5:1, install some forged pistons (cast will only hold up to that much boost for so long) and finish the port work on the heads.

Here's a boost compression ratio calculator: http://www.rbracing-rsr.com/compression.htm

Anyways I hope that cleared everything up.

 

the 749 idea is greta however it wont work with the vortec intake. the injectors are really bizare pwm deals. but i think you could retrofit some regualr sy/ty injector in there no big deal.

 

Well the problem being at the moment that I don't have a fuel rail for this system. I'll have to track one down, then I think I can use a set of injectors from a TPI off of an L98. I believe their 24lb injectors, so they won't be enough for the turbo, but they'll be enough to run the 4.3. Gotta crawl b4 I can walk. Once I get the engine running in the car I'll upgrade the injectors and get the turbo and manifolds. Does anyone know if a set of SYTY headers will fit a Camaro? If not I'll get to have the wondeful pleasure of building them myself (yes thats sarcasm).

 

i think sy/ty header should work post some engine bay pics with turbo location. ill give you my thoughts then

 

OK, I will as soon as I get the motor in. I have to rebuild a 4.3 for my dad's Blazer then I'll get his, so as soon as I get that in I'll post the pics. I have another 4.3 that I already tore down that will be the actual turbo engine, the one from the Blazer is just to get everything to mate up and work. Probably looking at a month b4 I finish the rebuild.