COMP CAMS, was wrong. Always degree your cam.
Thread Starter
Pro
Joined: Mar 2004
Posts: 508
Likes: 0
From: N.W. CT
COMP CAMS, was wrong. Always degree your cam.
Put a comp cam 08-467-8 in my engine. It was a small base circle grind.
So the cam should has a 4 degree advance ground into it from Comp.
http://www.compcams.com/Cam_Specs/Ca...?csid=209&sb=0
It was suppose to have a 109 intake center line. I ran the degree wheel 5 times and it came back to 113. I called comp and they stated "we check all of are cams".
I advanced the cam on my lower sproket 4 to make up the diffrence. Its good to go now. Im not sure if the small base program on the grinder has the 4 degree advance written on it, just something to keep in mind prior to just throwing a cam in and calling it Christmas.
So the cam should has a 4 degree advance ground into it from Comp.
http://www.compcams.com/Cam_Specs/Ca...?csid=209&sb=0
It was suppose to have a 109 intake center line. I ran the degree wheel 5 times and it came back to 113. I called comp and they stated "we check all of are cams".
I advanced the cam on my lower sproket 4 to make up the diffrence. Its good to go now. Im not sure if the small base program on the grinder has the 4 degree advance written on it, just something to keep in mind prior to just throwing a cam in and calling it Christmas.
Safety Car
Joined: Sep 2001
Posts: 4,160
Likes: 554
From: Glenbeulah Wi
I would suppect that their cam is correct. The crankshaft key, crankshaft, and timing chain set can all influence the position of the cam. You should always degree your cam, it will make sure any errors in any of the components are taken into account and eliminated.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
On another site, I read where the author had a similar problem (I believe it was 3 degrees though) but it turned out NOT to be the cam, but tolerance stack of his engine.
He found out by installing the same cam in another engine and it degreed in correctly. Then he install a DIFFERENT cam in both engines; on the first engine the different cam was, again, 3 degrees off, but in the second engine it was right-on.
Yep, degreeing is the best way. Alas, too few do it.
Jake
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
He found out by installing the same cam in another engine and it degreed in correctly. Then he install a DIFFERENT cam in both engines; on the first engine the different cam was, again, 3 degrees off, but in the second engine it was right-on.
Yep, degreeing is the best way. Alas, too few do it.
Jake
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
Thread Starter
Pro
Joined: Mar 2004
Posts: 508
Likes: 0
From: N.W. CT
On another site, I read where the author had a similar problem (I believe it was 3 degrees though) but it turned out NOT to be the cam, but tolerance stack of his engine.
He found out by installing the same cam in another engine and it degreed in correctly. Then he install a DIFFERENT cam in both engines; on the first engine the different cam was, again, 3 degrees off, but in the second engine it was right-on.
Yep, degreeing is the best way. Alas, too few do it.
Jake
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
He found out by installing the same cam in another engine and it degreed in correctly. Then he install a DIFFERENT cam in both engines; on the first engine the different cam was, again, 3 degrees off, but in the second engine it was right-on.
Yep, degreeing is the best way. Alas, too few do it.
Jake
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
The engine build is coming along. I will post some pics when it is complete.
Jake, congrads on your sons graduation. West Point is second to none. I meet alot of students from Yale, they are book smart but I feel some of them could not find a way out of a cardboard box.
Instructor
Joined: Dec 2004
Posts: 187
Likes: 70
Most all their off-the-shelf grinds have four degrees "built-in". However, I've ordered many custom grinds and if you say you want XYZ cam on a small base circle, that's considered a custom grind. Unless you request the four degrees put into the "custom" cam, they grind it "straight-up" (at least that's been my experience). I've degreed every cam I've installed since 1987,, most were Comp Cams and I've never had a Comp Cam that was off. Well,, no more than what I'd consider within my own margin of error.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
More often than not youll see timing sets that are off rather than cams but it is possible. Always double che k every part. A good machine shop will have whats called a cam doctor and can at least verify a number of specs. Neat little setup
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
I have done a couple that the timing chain set threw the cam timing out of wack. And changing the timing chain set brought everthing back in.
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Drifting
Joined: Dec 2005
Posts: 1,360
Likes: 3
From: NORTHEAST
Lifter bore placement and cam tunnel placement play a big part in valve timing events more so with a roller lifter as you are dealing with direct center lines rater then a flat tappet lifter which does not have the same effect.
We have seen cam tunnels off up to .016 and lifter bores of up to .025 plus. we have gone from .842 to .875 lifter bores and not have them clean up of that tells you anything.
Have never been very impressed with the generals work over the years.
The only true way to blame Comp cams is have the cam check on a cam doctor or equivilant.
We have seen cam tunnels off up to .016 and lifter bores of up to .025 plus. we have gone from .842 to .875 lifter bores and not have them clean up of that tells you anything.
Have never been very impressed with the generals work over the years.
The only true way to blame Comp cams is have the cam check on a cam doctor or equivilant.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
ROFL, I've may have a "cardboard box" candidate (daughter) too; Harvard Class of 2005. Well, not really, since the D.O.D. Terrorist/Intelligence folks gobbled her up right away, but I see your point.
Jake
My son, Ryan M. Cameron, graduated from West Point on 22 May 2010! He was commissioned as a 2nd Lieutenant and I pinned on his first pair of "Butter Bars" PROUDEST DAY OF MY LIFE!!
