New to the board, been a lurker for a while. Lots of good information, thanks in advance.

What do you guys think of this cam. Comp xr274 roller.
236 242 @.050
274 280 adv..
.602 .608 w/1.6 on a 110lsa

Going in a vortec headed 355cu
10.3:1 kB's
topped with an rpm air gap and a 750 double pumper.
Would you chose somthing maybe a little bigger? The motor will be run on pump gas, and im thinking with that little of adv duration and overlap along with high compression its ping ccity? Also how do you think it will idle, slight lope??


thanks
jake

 

Lotta work to those stock heads to install that cam.

For the same money it will take just to allow parts not to crash, you can get far better heads.

Borderline not enough compression.

Good cam for a hot street motor. Yeah, slight lope. Might fool a few people.

 

is this 355 based off an L98? I am just curious, because I am planning on running a cam with similar specs to yours (248/252, .609/.631 @ 1.5:1, 112 LSA) in an L98 based engine (same pistons) but I am wondering if there will be adequate P-V Clearance or if I'll need to flycut the pistons. I'd probably just hold out and wait for a stroker motor to put it in if it won't clear w/o flycutting. The cam is an LT1 cam, solid roller, small base circle. It's much better matched to the enormous heads I'm running than the lil ZZ-409 cam I'm running now.

 

thats way too much lift for vortec heads.

 

Lobe seperation angle (LSA) and overlap are 2 opposite things, but related to eachother.

Assuming duration remains constant, overlap increases as seperation angle decreases. Inversely, as you increase the lobe seperation, you decrease overlap.

As RB said, its a cam for a hot street motor.

 

Most Kb pistons have .26" valve reliefs (which is approx +.1" over stock and is enough for most big cams). You should check the relief depth at least.

Get a set of fastburns or something that will feed that motor the 6700 rpm the cam will run.

As far as the second poster ?
I would not turn any more RPM than the ZZ4 shortblock and it redlines at 5800.

http://www.gmpartsdepot.com/store/pr...Product_ID=456

Max. Recommended RPM ..... 5800

 

Get some better heads or a smaller cam.

Id go with HYD roller xe282 maybe the xe288 depending on the rest of the setup. Better on the valve train, no lash adjustment and still get the power you want.

A guy i work with did the motor in his 97 pickup
(vortec 350) decked, milled the heads, thinner head gasket & flat tops we guess about 10.2 or so compression running the stock cam! he runs midgrade in it and it runs fine even hooked it up to the computer to see if it was pulling timing at all and its not. we figure its do to the fastburn chamber maybe a bit because of the injection also.

You should be able to run a motor with a cam that size and 10:1 on 91 or 92