degreeing cam spec question and procedure

[recordsj]

You can measure either, but it's probably easier/more accurate to use the pushrod. To do the valve, you need to know the rocker ratio.

so if i degree the cam, by measuring with a dial gauge the lift of the push rods I just use the published open/close specs?

But if I degree it from the valve I need to do a conversion of the rocker ratio? How do you do the conversion?

 

[Hap Waldrop]

You can measure either, but it's probably easier/more accurate to use the pushrod. To do the valve, you need to know the rocker ratio.

so if i degree the cam, by measuring with a dial gauge the lift of the push rods I just use the published open/close specs?

But if I degree it from the valve I need to do a conversion of the rocker ratio? How do you do the conversion?

Well thats a bit more difficult, as the roackwer ratio of stock roacker seems to bounce around a bit they are somewhere around 1.25 t 1.

Cam lift x rocker arm ratio - valve lash = valve lift

 

[recordsj]

You can measure either, but it's probably easier/more accurate to use the pushrod. To do the valve, you need to know the rocker ratio.

so if i degree the cam, by measuring with a dial gauge the lift of the push rods I just use the published open/close specs?

But if I degree it from the valve I need to do a conversion of the rocker ratio? How do you do the conversion?

Well thats a bit more difficult, as the roackwer ratio of stock roacker seems to bounce around a bit they are somewhere around 1.25 t 1.

Cam lift x rocker arm ratio - valve lash = valve lift

so if i degree the cam, by measuring with a dial gauge the lift of the push rods I just use the published open/close specs?
Inlet valve: opens 18 BTDC
close 50 ABDC
Exhaust valve: opens 58 BBDC
closes 18 ATDC

Would this mean that the degree wheel should be at 18 BTDC when I first see any movement of the dial gauge on the pushrod?

 

[BlueMax]

I’m posting a link for you to read because it’s a lot of typing and it easier for you to see the illustrations of what you’re trying to achieve. The best way to degree a cam shaft is to find the centerline of the camshaft. This link shows you how to achieve that. I assume your trying to attempt to degree a stock cam since a performance camshaft manufacture would have provided the degrees for the IN and EX and your centerline. Locating centerline is the simplest way to degrees your cam. If you can locate centerline of your camshaft within 2 degrees you can consider that with in tolerance, preferably to the advance side. You have a 1500 engine which uses bolts to attach the timing gear to the cam. In order to achieve accuracy with in 2 degrees you will need a vernier cam timing gear. It would be almost impossable achieve this accuracy any other way. Here’s the link that will be informative with illustrations for you to understand what you need to do. It’s called camshaft 101 for the beginner. https://www.circletrack.com/enginetech/ctrp_0805_camshaft_timing/lobe_lift_centerline.html