Hi everyone, I've been reading for a long time but this is my first post. I have a question about a cam that I found in the back of the garage. It is a Comp Cams Xtreme energy cam, part # 12-246-3. Here are the specs from the website...

Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.487 0.49
Duration At 0.006 Tappet Lift 274 286

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Valve Timing At 0.006
Open Close
Intake 31 63
Exhaust 77 29

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These Specs Are For The Cam Installed At 106 Intake CL
Intake Exhaust
Duration At 0.05 230 236
Lobe Lift 0.325 0.327
Lobe Separation 110

I am wondering how compatible this cam is with TPI? I am also looking into an LT1 intake conversion, would this cam work with an LT1 intake? I guess I should mention that I have Sportsman II heads and headers.

 

It is not even remotely dimly slightly compatible with TPI. It is altogether too much cam to begine with, because it moves the power band up beyond that of the intake; and it is fuel injection hostile besides, because of the low and unsteady vacuum that it will produce.

It runs like a scalded dog in the right motor though. I had it in a 400 with a good set of heads and a big Holley carb on it, it was excellent.

For TPI, you don't want any more than about 220° of intake duration; and if you have that much intake duration, the lobe separation needs to be at least 114°.

If this is for a 350 with a flat tappet cam, look at the XE262-14. Not the regular XE262 which is on 110° lobe separation, but the -14, which is on 114°.

The XE274 would work a whole lot better with the LT1 intake, which doesn't have the acoustic tuning effect and the 3600 RPM peak torque and nothing beyond 4500 that the TPI design forces; although, getting the right engine tune would be a chore. But at WOT it should scream.

 

Thank you for the info. I think you just persuaded me to get the LT1 intake.