Valve Timing VS Centerline

Before I found you guys, I delved hours into Honda B series cam degree videos on YouTube. None of which made any sense in regard to calculating how much the cam gears needed to be adjusted.

(After taking your course, the way you teach it makes sense.)

Alot of what I was watching discussed degreeing using the centerline method.

My two questions are,

1. Is one method more precise than the other?

2. Could you explain how to calculate the amount of degrees the cam gears need to move after getting your measurements vs the spec sheet.

Hi...

I used to use degreeing wheel for dialing camshafts until I figured out how to use center line line method. I double checked it on other cars where camshafts were set by other people and it turned to be as accurate as using the degreeing wheel. From that point I always use centerline method if I know stock camshafts centerlines- it just saves so much time comparing to degreeing wheel.

This is how I do that (Evo 7-8 as example):

I know the stock Evo 7-8 with 4g63 has 109/110 (intake/exhaust) centerlines.

It means that intake camshaft peak valve lift happenes at 109 degrees After Top Dead Center and exhaust camshaft peak valve lifts happenes at 110 degrees Before Top Dead Center.

Now I want to drop in other camshafts with centerlines numbers 107/113.

For intake camshaft 109-107 =2, it means that intake camshaft has to be turned 2 degrees ATDC less than before (in crankshaft degrees). Since 1 degree on adjustable sprocket equals 2 degrees of crankshaft rotation I need to retard intake camshaft just one mark (1mark on sprocket =2 degrees crankshaft) counterclockwise since 4g63 rotates clockwise, from where it was before.

For exhaust camshaft 115-110=5, it means that exhaust camshaft has to be turned 5 degrees BTDC more than before (again in crankshaft degrees). Since 1 degree on adjustable sprocket equals 2 degrees of crankshaft rotation I need to retard exhaust camshaft 2,5 marks (2,5 marks on sprocket = 5 degrees of crankshaft rotation) counterclockwise since 4g63 rotates clockwise, from where it was before...

Needless to say that in stock position (109/110 centerline) both camshafts have to in netural position which isn't retarded or advances in adjustable sprockets- central marks of upper and lower sprocket part have to in in centered location.

It takes just a few minutes to dial them in...

I'm attaching cam card diagram so you can visualize it.