Building a 3.4 P/R

[Pretty Boy]

I'm looking to build a 3.4 camaro block for my fiero and i'm looking to build good power w/o breaking the bank or robbing one. I'm looking for any combo's you guys can give me like stock short block with 3500 heads gives me (14:1's) (((Example not fact))) but those and or like use cam button from SBC on it to help or what little things are good to do to better the over all motor and or help in oiling/lighting it up or things seating better.

My parts i have

3.4 90,000 mile block
P&P iron heads with locks and springs w/mid and upper intake
Set of 3400 heads w/mid and upper intake
2 3/4 TB's
1 3400 TB
stock fiero injectors,3400 injectors,3800sc injectors
Stock roller rockers off a 3400
Crane Cam 272H
Double roller chain for 3.4 P/R
High volume oil pump for 3.4 P/R

[Superdave]

If you posting in the pushrod section you don't have to call it a P/R.. that's assumed.. lol


3400 heads on that 3.4 would give you 13.29:1 SCR (.040 headgaskets), If you use that H272 cam your dynamic compression will be down in the 9's so you really won't have a problem with pump gas. Use the 3400 injectors, Some good headers, tune it and you'll have a healthy combo.

[Pretty Boy]

If you posting in the pushrod section you don't have to call it a P/R.. that's assumed.. lol


3400 heads on that 3.4 would give you 13.29:1 SCR (.040 headgaskets), If you use that H272 cam your dynamic compression will be down in the 9's so you really won't have a problem with pump gas. Use the 3400 injectors, Some good headers, tune it and you'll have a healthy combo.

Ok so 3400 head on my stock 3.4 bottom end and cam gives me like 9:1's? and what if i put 3400 heads 272h cam and DOHC pistons? would that be good to run with pump gas and under 11:1's? is that with in a good quench ratio?

motor idea is close to 10:1-11:1's and good flowing heads with 100shot and my sprint headers and good exhaust

[Superdave]

Ok so 3400 head on my stock 3.4 bottom end and cam gives me like 9:1's? and what if i put 3400 heads 272h cam and DOHC pistons? would that be good to run with pump gas and under 11:1's? is that with in a good quench ratio?

motor idea is close to 10:1-11:1's and good flowing heads with 100shot and my sprint headers and good exhaust

no, 3400 heads with your 3.4 pistons gives you 13.29:1 static compression, the dynamic compression takes into account for the camshaft profile. Good reading here: http://en.wikipedia.org/wiki/Compression_ratio


3.4 block, 3400 heads and 3.4 DOHC pistons would be 14.16:1 with .040 headgaskets giving .050" of quench

[Blacktree]

The Gen-3 heads (3x00) flow much better than the iron heads. So if the high compression ratio doesn't bother you, then go for the aluminum heads.

Also, I think the stock 3400 rocker arms are 1.6:1 ratio? If that's the case, a Crane H272 cam with those rockers will have some pretty radical lift & duration. The stock 3.4 rockers, however, are 1.5:1 ratio.

Also, since you plan to run a pretty aggressive cam & rocker setup, I would strongly suggest a double-roller timing chain.

One more thing: the F-Body 3.4 uses flat-tappet lifters. The added stress of an aggressive camshaft and/or stiff valve springs can wipe out cam lobes in no time. This is a common problem, now that engine oils are being formulated with little to no ZDDP. It is imperative to break in the cam & lifters using an oil that's high in ZDDP. There are specially formulated break-in oils for this purpose. Plus, some brands of engine oil (like Shell Rotella) also have sufficient amounts of ZDDP.

The stock Fiero injectors are rated at 15 lb/hr, which is just barely enough to feed a stock 3.4. The stock 3.4 injectors are rated at 17 lb/hr. And even they may not flow enough for your engine, with all those upgrades. This is just a guess, but I'd say your engine would need 19 lb/hr bare minimum... maybe as much as 24 lb/hr. You can find refurbished injectors on eBay for very reasonable prices. Or you can get new ones from Accel.

[Pretty Boy]

bump for some more info/help and blacktree i do have a double roller timing chain