Help degreeing cam shaft

[Jan Larsson]

Anyone got some simple to follow instructions to degree my new setup (Comp roller cam with roller chain setup)?

Got the degree wheel and do have some details in a couple of books how to do it but if anyone got a good simple step by step instruction that would be much appreciated.

 

[turbofabricator]

That's kinda like asking how to do a vasectomy. :biggrin: The best way to learn how to degree a cam is to watch someone else do it. Comp has a video available that would be a big help. Here is thier link on how to do it. http://www.compcams.com/Technical/Instructions/Files/145.pdf Take your time. As you read the instructions, and fiddle with the stuff, it will all start to sink in. You will need a piston stop, and a dial indicator with a magnetic base, too. Is the engine in the car? Are the heads on? There are different proceedures for with and with out the heads on. It is easier to do with the heads off, but it really doesn't matter. You will also have to fabricate a TDC indicator. I use a 4"-6" piece of coat hangar that I wrap around a short 5/16" bolt and secure it to the front of the block using a timing cover bolt hole.
With the crank keyway at the 1:00 position(near TDC), I try to get the TDC mark as close to my indicator as I can. Then I can re-bend the wire after I find true TDC, and I don't have to loosen the crank bolt and turn the degree wheel to line up. It is pretty confusing "reading" how to do it.

 

[Blown&Injected]

The Intake Center-Line method is easy. A google search will turn up many articles. I suggest you read a few because a few different wordings should help to make it more clear how to do it.

If the new chain is tight, you really don't have to have a piston stop - I had only about a quarter of a degree of movement on my degree wheel as the dial indicator had some dwell time at TDC.

Really do not need to degree a cam - a few degrees either way only moves to power range up or down 75 RPM's or so

 

[NCTURBOS]

I would definitely degree the camshaft. The last couple billet roller camshafts I installed were off quite a bit from the grinder.

Also, if you can't figure it out get someone to help you. I've seen piston-valve contact when it's not done correctly.


K.

 

[Blown&Injected]

WOW, must be some serious lift or way messed up cam. With a 218/212 .498 my valves did not even touch a 1/2" thick bar of clay on top of the piston.

Mine was off 2*'s so it would have moved the power band what? 50 rpm's.

I only degreed it and set it up exactly on the 112 centerline because I was making a photo journal and it looks cool/complicated, and the timing set makes it easy to go + or - oh yeah, and because the off-set on the key for the BHJ balancer was making me think that is introducing a static amount of error into what should otherwise accumulate into an acceptable amount of deviation from perfect specs

 

[NCTURBOS]

WOW, must be some serious lift or way messed up cam. With a 218/212 .498 my valves did not even touch a 1/2" thick bar of clay on top of the piston.

I had a car come up from S.C. a few years ago with a rebuilt motor in it, that upon tear-down all the valve were kissing the pistons. Their thought was to spin the whole crank over to the next tooth or two for the degree... not just spin the crank gear.

Recently just had another one with a .496 lift 206/206 roller that all the intake valves were touching the pistons. (GN1 aluminum heads). Whoever built this one must not have checked anything, as this problem was only just the beginning...

Just goes to show that there's more to an "engine builder" than just turning a few bolts.


K.

 

[Blown&Injected]

In my engine - stock heads with 1.77" valves there is so much room that it is hard to believe somebody could get it so far off that valves would hit.

When lining up the dots, there is just no way it looks right being off even one tooth. I have never had a problem just lining up the dots but I have always just used "off-the-shelf" relatively mild cams.

need to start re-sizing all the pics I took so you can see me degreeing a cam after all my ya don't need to do that talk and find that thread I started

 

[Jan Larsson]

Thanks guys, I've done some reading so will give it a go and see if it all makes sense when I try on my engine :biggrin:

I got the egnine in the engine stand with the heads off. Just put the bottom end together.