Degreeing Camshaft
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
Degreeing Camshaft
I was watching videos this morning of the procedure for degreeing camshafts. In all cases, only the lobes for #1 hole were checked. Do the others not have to be checked against the camcard and if not, why?
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
A bit confused. The camshaft as seen on the videos(several) only has one way of matching up to the crankshaft - "o" mark on each gear matching. Their only concern seemed to be that the actual measurements they took matched the cam card. But they only measured #1.
Burning Brakes
Joined: Apr 2014
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Degreeing the cam is for checking and setting the position of the cam in relation to the position of the crank. The differences in the individual cylinders (lobes) is ground into the cam and fixed. Set #1 and everything else lines up. (assuming the cam grind is right)
Advanced
Joined: Oct 2014
Posts: 94
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From: Tampa
Now think of everything that can occur in machining the crank, timing chain, gears, and cam that can tweak the position of those dots.
Remember that we are talking about degrees of a circle.
The first part of the degree process is to determine where you are in the relationship of piston tdc vs #1 cam lobe centerline.
If it is exactly where it should be (and it almost never is) then you are confirmed.
If it isnt where you want it, you then have to alter it to move it where it is intended.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
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From: near the thumb in the mitten
With your question directly it is assumed that the cam lobs are machined correctly. In racing for example nascar cam lobs may all be check to be sure it is exactly what builder wants. Degreeing is more about minor correcting of machine tolerances in cam dowel pin placement, timing chain set, crank keyway position to crankpin. The cam is designed to be installed in a certain position relative to TDC of piston. Degreeing is checking that relationship and adjusting or possibly finding a machining error prior to full assembly. On some occasions cam may want to be advanced or retarded a certain amount for performance reasons. Degreeing is necessary to do that accurately. ECM's have to be tuned if cam timing is intensional altered from specifications.
Thread Starter
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
With your question directly it is assumed that the cam lobs are machined correctly. In racing for example nascar cam lobs may all be check to be sure it is exactly what builder wants. Degreeing is more about minor correcting of machine tolerances in cam dowel pin placement, timing chain set, crank keyway position to crankpin. The cam is designed to be installed in a certain position relative to TDC of piston. Degreeing is checking that relationship and adjusting or possibly finding a machining error prior to full assembly. On some occasions cam may want to be advanced or retarded a certain amount for performance reasons. Degreeing is necessary to do that accurately. ECM's have to be tuned if cam timing is intensional altered from specifications.
Thank you! You have now answered the question that I asked.
