Camshaft Discussion Thread

[quickangel93]

Ok i would like to get more into detail in learning camshafts and how the degree affects a boosted motor.

Ok flipping though the pages of skunk2 parts catalog i notice that the degree on the turbo cams is smaller than the n/a cams. like you could get 260's, 270's 280's, but for turbo applications they list 220's, 230's. why so low?

Questions:

can i run a 272 cam in a turbo h22 or even 280?

with a proper tune, would i be fine?

wouldnt more degree cam open the valves more to suck more air into the cylinder?


I would appreciate some information on this before i go buying cams.

[CB7lx91]

the higher the cam number the steeper the lift is, which is usually a smaller duration I think. Which is better for high revving n/a's, and a lower number with a longer duration is good for jamming all that compressed air into the cylinder.

[F22Turbo702]

the higher the cam number the steeper the lift is, which is usually a smaller duration I think. Which is better for high revving n/a's, and a lower number with a longer duration is good for jamming all that compressed air into the cylinder.

I'm pretty sure you've got this backwards...

The number on the cam usually corresponds to the advertised duration, 272 degrees, 282 degrees, etc.

long duration= N/A
short duration= Turbo

But, advertised duration has very little to do with what the actual duration is. I've seen many cams labeled "272" and the actual duration measured @0.050" is anywhere from 205-240°.

Skunk2 has one of the best cam profiles for turbo. A lot of B-series guys are running the Pro-1 cams on their turbo motors, and even with the long duration they are making more power than with the old Skunk2 turbo cams.

Cam selection has a lot to do with what setup you're running. I've seen guys swap out 5 sets of cams until they found the most ideal profile for their motor.

Cam selection on a DOHC is much easier than on a SOHC, at least with a DOHC you can shorten the overlap by adjusting the cam gears, with a SOHC the overlap is set when they grind it. Selecting a cam for a SOHC motor is harder than selecting one for a DOHC.

I suggest that you start by checking the specs on the cam cards from some of the major manufacturers, most are available on their websites, and if you're still having trouble selecting a cam grind I would call Debbie from Web Camshafts in Riverside. She knows her shit and can help you select a cam for whatever setup you're running.

So I guess my summarized answer is yes, you could run a "272" or "282" cam on a turbo H22. I'd suggest the Skunk2's H-series Pro-1 for anything under 15psi, anything over that I'd recommend Web Camshaft's Stage 2 grind (grind#689-688-687/689-688-683) or the Skunk2 Pro-2's.

-Kyle

[quickangel93]

I'm pretty sure you've got this backwards...

The number on the cam usually corresponds to the advertised duration, 272 degrees, 282 degrees, etc.

long duration= N/A
short duration= Turbo

But, advertised duration has very little to do with what the actual duration is. I've seen many cams labeled "272" and the actual duration measured @0.050" is anywhere from 205-240°.

Skunk2 has one of the best cam profiles for turbo. A lot of B-series guys are running the Pro-1 cams on their turbo motors, and even with the long duration they are making more power than with the old Skunk2 turbo cams.

Cam selection has a lot to do with what setup you're running. I've seen guys swap out 5 sets of cams until they found the most ideal profile for their motor.

Cam selection on a DOHC is much easier than on a SOHC, at least with a DOHC you can shorten the overlap by adjusting the cam gears, with a SOHC the overlap is set when they grind it. Selecting a cam for a SOHC motor is harder than selecting one for a DOHC.

I suggest that you start by checking the specs on the cam cards from some of the major manufacturers, most are available on their websites, and if you're still having trouble selecting a cam grind I would call Debbie from Web Camshafts in Riverside. She knows her shit and can help you select a cam for whatever setup you're running.

So I guess my summarized answer is yes, you could run a "272" or "282" cam on a turbo H22. I'd suggest the Skunk2's H-series Pro-1 for anything under 15psi, anything over that I'd recommend Web Camshaft's Stage 2 grind (grind#689-688-687/689-688-683) or the Skunk2 Pro-2's.

-Kyle

thanks bro. ill have to give her a call