Lumpiest, bumpiest cams for a 3.2 using stock valve train?

[Tippy]

Cross post from 911 tech forum

I'd like to keep the same springs, retainers, and keepers, but want lumpy sounding cams.

I have a 3.4L flat-top pistoned 3.2 running boost.

It really falls on its face at 6k RPM, and would like a little more powerband. Will not turn over 6750.

Next question, what costs are involved valve train wise going to, say GT2 Evos?

TIA

[Rufian]

Ruf Btr grind, should do it, cheers.

[cgarr]

What cam are you running now? are you at the optimal overlap for top end?

[Tippy]

Originally Posted by Rufian

Ruf Btr grind, should do it, cheers, Stef.

Hello Stef., you have specs?

[Tippy]

Originally Posted by cgarr

What cam are you running now? are you at the optimal overlap for top end?

Hello Craig, just the stock 3.2 ones. I don't remember what I timed them to. You still refurbing rockers and shafts?

[cgarr]

yes, email me at: garrett@iserv.net your mail box is stuffed full and ***** is falling out on the ground.

[stownsen914]

I used an Elgin 310-296 grind on a 2.7L race motor using stock valves and stock early 911S springs, revving to 7500. It's a fairly hot cam with like .490" lift and 270 duration (.050") on intakes and .470" and 255 duration on the exhaust. Not exactly a recommended setup, but I got 60 hours out of the engine with no noticeable issues. I'll be replacing iwth lightweight valves and heavier springs when I tear it apart as insurance and so I can rev it a little higher.

Scott

[Tippy]

Craig, I'll email in a sec.

[Tippy]

Originally Posted by stownsen914

I used an Elgin 310-296 grind on a 2.7L race motor using stock valves and stock early 911S springs, revving to 7500. It's a fairly hot cam with like .490" lift and 270 duration (.050") on intakes and .470" and 255 duration on the exhaust. Not exactly a recommended setup, but I got 60 hours out of the engine with no noticeable issues. I'll be replacing iwth lightweight valves and heavier springs when I tear it apart as insurance and so I can rev it a little higher.

Scott

Are "S" springs the same as 3.2's?

[cgarr]

Check with Dougherty (camgrinder) I have his super cup cams in my 3.4 10.5/1 twin plugged but im running stock intake, not sure if these would work for your setup but this is rev limited to 7200 and powers right up to it quickly.

[Tippy]

Stock valvetrain?

[cgarr]

Yep, good to around 7400


Sent from me

[Bird911]

Hi Craig,
Did you put your engine on a dyno ?
I am also building a 3.4 twin plug, 10.5:1 with the 993SS cams from Dougherty. Seem like the only difference with yours is my intake will be Jenvey ITBs. I also have the stock valve train so I was only hoping for about 6750 max rpm. I'm glad and surprised to see that you go to 7200 -7400 without floating. (I do have ARP rod bolts)
I was curious to know how many HP you get out of this setup.

[Tippy]

Originally Posted by cgarr

Yep, good to around 7400


Sent from me

Wow! Didn't realize that would even work! Hmmm

I'm sticking to 6750 due to the heavy Max Moritz pistons plus boost. Although it'd make power over 7, I'm going to stay shy of that due to advise of Steve Weiner.

[Tippy]

Originally Posted by Bird911

Hi Craig,
Did you put your engine on a dyno ?
I am also building a 3.4 twin plug, 10.5:1 with the 993SS cams from Dougherty. Seem like the only difference with yours is my intake will be Jenvey ITBs. I also have the stock valve train so I was only hoping for about 6750 max rpm. I'm glad and surprised to see that you go to 7200 -7400 without floating. (I do have ARP rod bolts)
I was curious to know how many HP you get out of this setup.

With ITB's I'd run over 7k to take advantage of them!!

[stownsen914]

Originally Posted by Tippy

Are "S" springs the same as 3.2's?

Supposedly they are different, but I could not tell you how. I believe the S springs had a white stripe on them to indicate that they were different.

[cgarr]

Originally Posted by Bird911

Hi Craig,
Did you put your engine on a dyno ?
I am also building a 3.4 twin plug, 10.5:1 with the 993SS cams from Dougherty. Seem like the only difference with yours is my intake will be Jenvey ITBs. I also have the stock valve train so I was only hoping for about 6750 max rpm. I'm glad and surprised to see that you go to 7200 -7400 without floating. (I do have ARP rod bolts)
I was curious to know how many HP you get out of this setup.

I have not had it on a dyno, run a lot of track days and have bounced it off the limiter at times, I could be on the edge so try not to but it does happen at times since it just wants to keep going. I have the older J&E pistons which some are saying can self destruct at times? Other than that I have ARP rod bolts too. It was pretty much how most were building them back in 2005

[Bird911]

Well it's good to know you can get to these RPM levels. With the high cost of building these engines nowadays, my first goal is still long term reliability, power/torque coming second. I will stick with a redline of about 6700-6800. Sorry Tippy !

Understood what you say about the JE pistons. I have the last production run, and the design is really different from a couple of years ago.