High performance DOHC?

slow'n'steady · Post by **slow'n'steady** » Sun Sep 03, 2006 11:49 pm

EDIT: back story gone... i wont be spending $10K on the fiero, only a couple thousand. you'all must have missed the part about me buying the crotch rocket

Now as some of you know i have the DOHC swap completed and i have almost "everything" i need to do my turbo install (minus A/W intercooler and piping). I was planning on running like 8# daily and may be 10 when i hit the track. Now i am thinkin with that extra money i could buy a spare DOHC short block and have it built to handle say around 16# of boost. What would be needed to achieve this?

i know abouth the SBC rods, but can i use the H beam rods, or what will handle that boost?

What about pistons? any options other than custom ones gettin made?

fuel? what size injectors would i need?

Any info would be great, like i said this is an idea... not saying 100% that i am going to do it, but i would REALLY like to depending on how much is involved. ill be doing the body stuff for sure!![/quote]

donk_316 · Post by **donk_316** » Mon Sep 04, 2006 12:03 am

Invest it and save it for something IMPORTANT. Assume a morgage or two and rent them out.

The Dark Side of Will · Mon Sep 04, 2006 12:07 am

Ditto on the important stuff... Can you go to full-blown college rather than vocational school?

Not that there's anything wrong with vocational school... but if you can hack a 4 year degree, by all means do so.

How old are you?

Post by **eHoward** » Mon Sep 04, 2006 12:16 am

or GOOG calls.

I wouldn't blow 10k on a fiero unless you've got plenty of extra money.

Now you'll know not to tell a background story in TECH if you want your question answered!

donk_316 wrote:Invest it and save it for something IMPORTANT. Assume a morgage or two and rent them out.

product1620 · Post by **product1620** » Mon Sep 04, 2006 12:41 am

wow, im sorry I thought I was in tech, oh well. Yea don't spend your money on the fiero, cause fieros are teh suxxxors, you should spend it on something coool like a skyline or a supppra or an sti or hell anything import cause imports fucking OWN domestic econo boxes like our POS fieros. All hail the mighty import! only spend your money on imports!

BTW when this gets edited out please consider editing out all the other posts that have absofuckinglutely SHIT to do with the questions he asked. K thnx have a nice day! :thumbleft:

donk_316 · Post by **donk_316** » Mon Sep 04, 2006 2:10 am

product1620 wrote:wow, im sorry I thought I was in tech, oh well. Yea don't spend your money on the fiero, cause fieros are teh suxxxors, you should spend it on something coool like a skyline or a supppra or an sti or hell anything import cause imports fucking OWN domestic econo boxes like our POS fieros. All hail the mighty import! only spend your money on imports!

BTW when this gets edited out please consider editing out all the other posts that have absofuckinglutely SHIT to do with the questions he asked. K thnx have a nice day! :thumbleft:

Im sensing... hostility towards imports...

Shaun41178(2) · Post by **Shaun41178(2)** » Mon Sep 04, 2006 10:22 am

probably because he got owned by an import while he was rolling in his fiero with his girlie acting all hard bragging about his low end tq to 30 mph

slow'n'steady · Post by **slow'n'steady** » Mon Sep 04, 2006 11:27 am

oops....

p8ntman442 · Post by **p8ntman442** » Mon Sep 04, 2006 11:52 am

FUCK THE RIDES.

put all that money in a 10 year CD.

come back in 10 years and say THANK YOU P8ntman442 you were so smart.

The Dark Side of Will · Mon Sep 04, 2006 12:18 pm

I think you'd be OK with stock rods for that boost level. I would go with forged pistons, however. Every other kind of 60 degree V6 has a bigger dish than the TDC/DOHC. Look at forged pistons for a pushrod 3.4. Shaun will know more, but I think there is a MFG that makes them.

There are 270/360 degree grooved main bearings available to improve rod oiling. Get those.

SBC rods need to be narrowed to work on the V6 crank. I've heard that they also need to be rekeyed to fit V6 bearings. I don't see why the bearing couldn't be narrowed with the rod, but I haven't looked at the problem in-depth myself *yet*.

Series8217 · Post by **Series8217** » Mon Sep 04, 2006 1:36 pm

One advantage to the SBC rods lies in increasing your redline. GM rates all the 60*V6 rods at 7000 RPM. If you get the right SBC rods they should be good for much more..

stimpy · Post by **stimpy** » Mon Sep 04, 2006 1:44 pm

Spend your money on hookers and crack.

slow'n'steady · Post by **slow'n'steady** » Mon Sep 04, 2006 2:30 pm

OK, so is there a detailed post or something about using the SBC rods in the DOHC? what rods can be used? will stock SBC rods handle it or do i need "performance" rods? also how much do they need to be narrowed and how would i go about explaining to a shop what needs done to them?

will upgrading the rods and pistons be enoungh? or do i need to do something with the block itself?

Aaron · Post by **Aaron** » Mon Sep 04, 2006 2:34 pm

Series8217 wrote:One advantage to the SBC rods lies in increasing your redline. GM rates all the 60*V6 rods at 7000 RPM. If you get the right SBC rods they should be good for much more..

I agree, but we have seen a few DOHCs running past 7k without any problems, though not at the power levels of a turbo DOHC, and not much past 7 (7500, maybe

. I'd like to turn my DOHC to 8, see how long it lasts, but I'm not sure if I'll have the cams to do it.

Furthermore, I don't think he'll need to turn past 7, or be able to on the stock heads/cams/intakes. With a good turbo setup, more power is a twist of the knob away.

The Dark Side of Will · Mon Sep 04, 2006 2:53 pm

slow'n'steady wrote:OK, so is there a detailed post or something about using the SBC rods in the DOHC? what rods can be used? will stock SBC rods handle it or do i need "performance" rods? also how much do they need to be narrowed and how would i go about explaining to a shop what needs done to them?

will upgrading the rods and pistons be enoungh? or do i need to do something with the block itself?

Factory SBC rods are minimally stronger than factory V6 rods, if at all. You definitely need aftermarket Chevy rods. You'll have to specify SMALL JOURNAL Chevy rods. The small block initially had 2.000" rod journals and later stepped up to 2.100" rod journals. You need rods for 2.000" journals. Those are common, don't worry.

I think the block will handle 15 psi without issue. A possibility if you have the scratch to blow on the machine work to install them, would be 4 bolt caps on the center two mains, but I don't think those will be necessary.

product1620 · Post by **product1620** » Mon Sep 04, 2006 3:14 pm

donk_316 wrote:
product1620 wrote:wow, im sorry I thought I was in tech, oh well. Yea don't spend your money on the fiero, cause fieros are teh suxxxors, you should spend it on something coool like a skyline or a supppra or an sti or hell anything import cause imports fucking OWN domestic econo boxes like our POS fieros. All hail the mighty import! only spend your money on imports!

BTW when this gets edited out please consider editing out all the other posts that have absofuckinglutely SHIT to do with the questions he asked. K thnx have a nice day! :thumbleft:
Im sensing... hostility towards imports...

No, but it seems that everyone is cool if you say im droping 15k on a skyline or 30k on an Evo, but if you say your putting some money into the fiero, its a different story; it suddenly turns into noooooo, save your money, invest in your future. He already said he was going to school, give the guy some credit, hes not dropping out of school to become a proffesional street racer. Its his money, let him do with it what he wants, this is TECH; he asked a tech question, not "what do yall think I should do with my money". I have no beef with imports at all; I just don't like the elitist mentality that comes with a lot of their owners.

/end rant

product1620 · Post by **product1620** » Mon Sep 04, 2006 3:17 pm

Shaun41178(2) wrote:probably because he got owned by an import while he was rolling in his fiero with his girlie acting all hard bragging about his low end tq to 30 mph

Yea, thats it shaun; im all about the low end torquezorz! I only hope that one day I can be as cool as you. :salute:

Series8217 · Post by **Series8217** » Mon Sep 04, 2006 8:51 pm

Aaron wrote: I'd like to turn my DOHC to 8, see how long it lasts, but I'm not sure if I'll have the cams to do it.

You're willing to risk your motor to test GM's printed rating of 7000 RPM for the rods? Go for it! :thumbleft:

Aaron · Post by **Aaron** » Mon Sep 04, 2006 9:24 pm

Series8217 wrote:
Aaron wrote: I'd like to turn my DOHC to 8, see how long it lasts, but I'm not sure if I'll have the cams to do it.
You're willing to risk your motor to test GM's printed rating of 7000 RPM for the rods? Go for it! :thumbleft:

Something like that :thumbleft:

I doubt I'll be able to turn it that high though, I simply don't think I'll have the cam, even with timing them.

Kohburn · Post by **Kohburn** » Mon Sep 04, 2006 9:49 pm

if you want to boost the 3.4 dohc - and only run 8-10 psi, then forged pistons is about all you would need internally - spend the rest on the turbo and intercooler

Real Fiero Tech

High performance DOHC?

High performance DOHC?

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