Re: Cam Degree Install Question? Long.
[Re: Classof70Chally]
#221260
02/11/09 04:36 PM
02/11/09 04:36 PM
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Joined: Feb 2007
Posts: 5,080 organ
maximum entropy
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installed centerline is 106, which is 4 degrees advanced. if you installed it straight up, it would be at 110 i/c, 4 degrees retarded. you would not be happy. it needs to be at 106.
for what is the good life if not doing things thoughtfully?
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Re: Cam Degree Install Question? Long.
[Re: maximum entropy]
#221262
02/11/09 05:12 PM
02/11/09 05:12 PM
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Joined: Feb 2004
Posts: 3,076 Renton, Wa.
Classof70Chally
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Quote:
installed centerline is 106, which is 4 degrees advanced. if you installed it straight up, it would be at 110 i/c, 4 degrees retarded. you would not be happy. it needs to be at 106.
OK, you might have lost me there but the crank and cam sprockets are lined up at 0-0 and using the degree wheel and doing the check procedure I get 106' which is the centerline value given for the cam. I've heard of advance being "built in" by cam makers if that is what you are referring to? BTW the crank sprocket adjustments are in 2' increments only (not a 'hex-a-just' unit) .
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Re: Cam Degree Install Question? Long.
[Re: Classof70Chally]
#221263
02/11/09 07:17 PM
02/11/09 07:17 PM
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if you're at 106, you're good. like dthemi said, 105 or 105.5 would be good if you have chain drive. i usually go 1/2 degree (105.5)."straight up" on that cam would be 110, whatever the lsa is. if you installed 114 lsa cam at 114, that would be "straight up".
Last edited by maximum entropy; 02/11/09 07:19 PM.
for what is the good life if not doing things thoughtfully?
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Re: Cam Degree Install Question? Long.
[Re: Classof70Chally]
#221264
02/11/09 07:26 PM
02/11/09 07:26 PM
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Sport440
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Comp grinds 4* advance into alot of thier cams. Your cam with the gears 0,s lined up measuring a 106 intake centerline is indeed 4* advanced. If the cam wasnt ground advanced and your timing gears 0,s lined up with a 110 intake cemterline would be Straight up. The term Straight can be confusing. Its more then just lining up the dots or the 0,s of the gears. Its the cam being installed dead center between the intake and exhaust lobes at the pistons TDC between the exhaust and intake stroke. With a 110 lobe sep cam In cam degrees if centered at the pistons TDC it will be 55* away from exhaust lobe peak and 55* away from intake lobe peak. So this cam would be centered and considered Straight up by All the cam manufactures. And because the crank turns double of the cam, 55 cam* equals 110 crank* So a 110 LS cam will centerline if Centered at 110 crank ATDC Putting it at 106* intake centerline would be 4* advanced. If none of the above makes sence dont worry about it. You are indeed 4* advanced now at 106* mike
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Re: Cam Degree Install Question? Long.
[Re: Classof70Chally]
#221270
02/11/09 11:18 PM
02/11/09 11:18 PM
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Joined: Nov 2007
Posts: 21,845 Kirkland, Washington
Pacnorthcuda
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Quote:
It seems to me that the last time I did this I used the .050 before/after max lift also. This time the instructions I was using recommended .010. As far as my saying I installed the cam 'straight up' perhaps my terminology leaves a bit to be desired. What I should have said was something like zero to zero, in other words I just lined up the marks, checked the degree wheel and got a value of 106'.
Steve--it doesn't matter what value .010, .020, .050. 0r even .100 you use as long as its the same on each side of the lobe (small concession for asymetrical lobes of course). When you degree, you can pick several numbers, check them, and you will get the same results within the tolerance/resolution of your system (gauge/pointer/wheel/consistency etc). The last one I did I used three different values and came up with 106.75, 106.75, and 106.5. I figured that to be 106.75, with pretty good confidence. You needn't be concerned if you used .010 or .050
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Re: Cam Degree Install Question? Long.
[Re: Classof70Chally]
#221271
02/11/09 11:30 PM
02/11/09 11:30 PM
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Joined: Jan 2003
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Sport440
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Class of chally you stated it somewhat okay IMO. Lots of people refer to straight up as lining up the dots. Even though its not absolutly correct. In requards to 602 he is refering to another method of degreeing the cam. Not .050 from both sides of the intakes lobe max peak, but opening and closing crank degrees at .050 tappet lift. I feel both ways work just fine. I myself prefer the peak lobe ICL. But I actually will view all 3 numbers. The opening lobe crank* at .050, the peak ICL and the closing crank* at 050 on the intake lobe. As an example I will use your cam with its 224* duration @ .050 If at its intake lobe peak its at 106* ATDC With a 224* duration that means there is 112* of duration above .050 before and after that 106* Intake centerline point. So to find the intake opening point at .050 subtract 106* of ATDC away to get you to TDC from 112* That leaves 6* left that will be BTDC Do the same kind of math for the closing at .050 after 106 CL and you get 74* to BDC + 38* ABDC to =112* So your cam with 224* duration @ .050 installed at a 106 ICL will have the following timing numbers. INT opens at 6* BTDC @ .050 and closes at 38* ABDC @ .050 So theres the 2 ways to degree a cam. Or you can line up some dots or zeros and say its??? depending on the cam and other stuff. mikre
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Re: Cam Degree Install Question? Long.
[Re: Sport440]
#221272
02/11/09 11:46 PM
02/11/09 11:46 PM
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Joined: Feb 2004
Posts: 3,076 Renton, Wa.
Classof70Chally
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Thanks for the input. I guess with somewhere just north of $6K pounded into this 'street' motor I want to make sure I cover all the bases. OOOPS! Hope my wife doesn't see this!
Last edited by Classof70Chally; 02/11/09 11:47 PM.
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