I'm still trying to understand how cam profiles work and lift etc. I know for a fact that 265 are street friendly with gains, 272 for higher HPs then 280 for full race and highly built motors.

Now my questions is, I saw a weird profile out of the common ones you see. This company build rally engines like there's not tomorrow. I was looking at their cam specs (the cams for eve 9 is discontinued) and I saw unusual specs.

The can specs are: 265 with 12mm lift

Can someone explain to me what are the possible benefits of this cam and why it has a very high profile and what could affect the engine and such.

 

^ the 265, 272, and 280 you speak of is duration. It dictates how long the valve is open. The lift dictates how far open the valve goes. The higher the lift, the more open the valve is. Both affect air flow in a different way as you can imagine.

 

A 265* 12mm lift cam would idle poorly but make a ton of low/mid torque.

Don't take a cams profile by what they say, a Comp 280 cam for an Evo 8 is pretty mild and only has a duration of 264* in. and 265* ex. with 11mm/10.8mm lift.

 

Cam duration is usually quoted at a specified lift usually like .025" or .050" to ensure accurate comparison between cams ie 265 degrees at .050 lift.

FWIW....high lift with only a moderate increase on duration is a mid range type cam. works very well on turbo engines as the short duration and subsequent overlap help keep back pressure from the exhaust ( reversion ) a bit lower in the cylinder and EGT's down. Tougher on valve springs though.

YMMV

 

So is there a way to counter the idle to be street friendly with this type of spec?

Like a combination of pistons and rods for a different compression but keeping it on 2.0L?

 

if its 265* seat to seat, the idle wont be that bad. i really wouldnt worry about it.

 

If its Piper its 265 seat to seat. That would be a mellow cam for a Rally car level powerband (3-5k). The lift is to force as much into the cylinders as you can when its on the wrong side of the restrictor and then focus on the power. That is similar to an S1 with 0.8mm more lift. MIVEC mapping can cure alot of your issues.

Aaron