Comparing cams by the advertised duration
Thread Starter
Registered User
Joined: Mar 2004
Posts: 35
Comparing cams by the advertised duration
I was looking at Comp Cams mechanic roller cams and they seem to have a low advertised duration for the 0.050" duration numbers. However, the advertised duration is listed at a 0.015" tappet lift for solid rollers and at a 0.006" lift for hydraulic rollers. Unfortunately Comp Cams does not provide opening/closing events at 0.050" lift.
Can anyone make an advanced comparison of the following cams:
The infamous CC306:
http://www.compcams.com/Technical/Se...umber=07-306-8
and a much more aggressive 242/248/110 solid roller:
http://www.compcams.com/Technical/Se...umber=12-771-8
According to the advertised duration numbers, CC306 has 74 degrees of overlap while the solid roller only has 63. That's probably because it's measured at a different tappet lift.
I'm wondering how the idle quality and vacuum as well as the peak hp rpm will compare between these cams.
Hopefully this topic is advanced enough and thanks for the response.
Can anyone make an advanced comparison of the following cams:
The infamous CC306:
http://www.compcams.com/Technical/Se...umber=07-306-8
and a much more aggressive 242/248/110 solid roller:
http://www.compcams.com/Technical/Se...umber=12-771-8
According to the advertised duration numbers, CC306 has 74 degrees of overlap while the solid roller only has 63. That's probably because it's measured at a different tappet lift.
I'm wondering how the idle quality and vacuum as well as the peak hp rpm will compare between these cams.
Hopefully this topic is advanced enough and thanks for the response.
Registered User
Joined: Sep 2002
Posts: 655
Re: Comparing cams by the advertised duration
My take from viewing both cam cards is that Grind Number CS XR280 R-10
is edging on race/strip cam territory.
Looking at the .05" lift values, the CS XR280 R-10 is much more aggressive
and will drop the manifold pressure dramatically at idle.
You would probably require a vac. cannister if this camshaft were to be installed
in a daily driver.
The intake valve timing at even 0.015" will bleed off a good bit of cylinder pressure
at idle- low RPM (IVO> EVC).
Static compression will need to be in the 10:1+ range to pick up the slack
These numbers are fairly similar to my CC 292H camshaft. It's not really
meant for a street motor.
My guess is that HP will peak after 5900 RPM depending on your engine config of course.
is edging on race/strip cam territory.
Looking at the .05" lift values, the CS XR280 R-10 is much more aggressive
and will drop the manifold pressure dramatically at idle.
You would probably require a vac. cannister if this camshaft were to be installed
in a daily driver.
The intake valve timing at even 0.015" will bleed off a good bit of cylinder pressure
at idle- low RPM (IVO> EVC).
Static compression will need to be in the 10:1+ range to pick up the slack
These numbers are fairly similar to my CC 292H camshaft. It's not really
meant for a street motor.
My guess is that HP will peak after 5900 RPM depending on your engine config of course.
Last edited by Zero_to_69; Mar 2, 2005 at 07:57 PM.
Banned
Joined: Oct 2002
Posts: 6,518
Re: Comparing cams by the advertised duration
How about this.....
Overlap Area in deg*sq-in
CC306 HR = 13.2
CC771 SR = 16.3 (with a .014/.016 lash)
Overlap at .050
CC306 HR = 13*
CC771 SR = 25*
Idle Vacuum difference probably around 2-3" of Hg less
Bret
Overlap Area in deg*sq-in
CC306 HR = 13.2
CC771 SR = 16.3 (with a .014/.016 lash)
Overlap at .050
CC306 HR = 13*
CC771 SR = 25*
Idle Vacuum difference probably around 2-3" of Hg less
Bret
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
Re: Comparing cams by the advertised duration
Vacuum... at what rpm?
The XR280 is a good cam... been around a while and makes good power when the induction is up to snuff. Should pull ~9-10" Hg in a 350 cid engine with a 900 rpm idle. I'd suspect it'd do 2-3" more in a 383.
IMO, the 280 is a nice cam for a stroker with lots of head ans intake work. Just make sure to watch your dynamic compression. Reducing the quench, which you need to do anyways, will get you part way there.
-Mindgame
The XR280 is a good cam... been around a while and makes good power when the induction is up to snuff. Should pull ~9-10" Hg in a 350 cid engine with a 900 rpm idle. I'd suspect it'd do 2-3" more in a 383.
IMO, the 280 is a nice cam for a stroker with lots of head ans intake work. Just make sure to watch your dynamic compression. Reducing the quench, which you need to do anyways, will get you part way there.
-Mindgame
Thread
Thread Starter
Forum
Replies
Last Post