3.4 valve spring options

[Fedaykin]

so I have a 95 3.4 from a camaro i'm working on... I got a comp cams kit for my valvetrain, new cam, lifters, pushrods, rockers, retainers, springs...

I'm really paranoid about float and heard that stock springs float pretty quickly... I dont think the comp cams springs are that much of an improvement though they are dual spring.

what other options do I have for springs? I'm looking to rev maybe to 7000 after I get the rev limiter removed, that might not be for a while though... and I dont want to have TOO heavy a spring like that guy who runs to 8000 RPM on his cavilier on this forum...

I guess i'm looking to the middle of reliability-wear / performance.

so would a set of crane springs be better or should I think about a mild LSx/LTx spring?

[geoffinbc]

You can install some LSx springs or Comp beehive springs with the correct retainer. What are the specs on the spring you have. I bet they are over 100lbs seat and over 300lbs open it should be fine. But show us the specs and let us know.

[Fedaykin]

CompCams Valve Springs
1993-1995 3.4L V6
Rate: 302 lbs./in.
1.230" OD w/Damper
.821" ID
Seat Load: 91 @ 1.700"
Open Load: 229 @ 1.250"
Coil Bind: 1.260"

[geoffinbc]

What cam is this? With springs like that there is no way in hell a cam matched with it will even approach 7K. Your lucky to get over 6K. Is this the comp 260 Cam?

[Fedaykin]

yeah thats it...

what do you mean wont approach 7000? i'm a valvetrain n00b.

u mean not tuned for much power or benifit over 6000 RPM?

[geoffinbc]

Yea you cant drop in a cam and remove the rev limiter and think it will go to 7000RPM or any RPM for that matter. The design of the cam will dictate what rannge it will operate in and what RPM range it will make power.

So if you are using the Comp 260 cam then dont expect much power over 5500RPM. In that case the springs in the kit are ok.

[Fedaykin]

When i was shopping i just picked a cam that would be better than stock, it IS better than stock right? I basically didnt want to fail emissions either.

but since a cam swap is easy peasy i'll do it again later... just so I know for the future, what cam would I be looking for? a custom grind? you got any specs you could recommend? like I said i'm interested in revving to about 7200 probably... kinda the same as my miata used to be. I was planning on getting a more aggressive cam once I got a turbo in a few years and went after a full performance rebuild.

[geoffinbc]

Eeek 7000+ RPM on a 3.4L iron head aint going to be very easy. You will have to port the intake and heads to really promote breathing.

A cam like this bugger will let you spin nice and fast.

http://www.cranecams.com/?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=CHEVROLET&Year=1995&Engine_Size=2.8-3.1%20L&partNumber=251241&partType=camshaft

However now you have sacraficed alot of streetability.

Your are going to have to run a Crane Dual Valvespring (9983 Or Comp 986/987 dual springs or 26918 beehive springs with Comp retainers.

[Fedaykin]

I've been doing some bench porting of the heads, and polished the combustion chambers, gasket matched the intake manifold...

yeah, I dont know where the project is going yet... i'll have to see once i get it running and decide where it needs to go from there.

when it says minimum RPM 3800... does that mean its just gross below that? I mean... when i'm cruising I dont need a lot of power, so if its just big power drop off that wont be a problem, thats what downshifting is for right? its not gonna stall or something below that is it?

[geoffinbc]

No it wont stall. But it will be lopey as hell at idle. It will need a very custom tuned ECM or a Carb to make it run. It will have little power below 3500 but it still wont be good for cruising because it will proabably be surging up and down. You will be drinking gobs of gas too. Not to mension the mechanical lifters will need adjustment from time to time and it will be much noisier.

Go with a Crane 272 cam. It should let you spin upto 6000RPM which is safe for all stock components. You will have awsome streetable power.

[BillS]

FWIW you will not easily be able to get a cast iron head 3.4 to perform (and still be making power) at 7000 RPM. The breathing is frankly dismal and your better bet would be to go the alloy head route, although the catch 22 is that there is almost no speed equipment available for these better breathing engines.

If you are willing to settle for 6000 rpm, use a cam as suggested, AND you will have to go to a larger throttle body (I ended up with a 62 mm version).

If you really like RPM, you need to look at the OHC version