Agreed, a few degrees does make a difference & I've seen as much as 6 degrees variance between the tolerances of the crank keyway, timing set & the camshaft. I've also checked many that were within 1 degree, but at least we knew.
You probably can find someone to loan you a degree wheel & an indicator.

 

Looking to see if I can borrow one from somewhere

 

...i just stuck my cam in and went...no problems here.

 

One other thing I recall, when I got my custom ground Comp Cam, in addition to being 2 degrees retarded, the Optispark drive pin was about .050" longer than the stock pin. I ground it down to the correct length and checked the fit in the Optispark drive coupling with Prussian Blueing to make sure it wasn't bottoming out.

Chris

 

In my opinion, it's all part of blueprinting. If you are doing a complete and typically expensive build, then it shouldn't be overlooked because you could have tolerance stackups on all the custom parts (or a downright mistake), on the other hand if you are doing a mild cam swap on an otherwise near stock engine, then it might make less of a difference if it is off a smidge. Over the years, I've found that there's been a little something wrong with about 30% of the parts I've bought. It's best to give it all a close look and make any corrections you need to then just having blind faith that it's all perfect. That goes for machine work, too.

 

Every single motor I have had built or built myself has had the cam degreed. It is a intergal part of a good performance motor build.

 

Dyno Don went to install a customers Lunati cam in a motor and it was off by 7 degrees. Not uncommon to find a cam off a couple of degrees.

I have the DynoSim motor simulation program. Using this program and changing the degrees can make say a 20hp difference. With my new combination and using the Comp Cams XFI218 cam I found that a 3 degree retard works the best. The program shows no more than a 5HP loss down low but a 15hp gain in the upper rpms from being installed at 0 degrees.

 

A guy who does cams for a living told me that your average off the shelf grind (cast core) is not uncommon to see 2-6º off of the advertised duration . Less with a billet grind that is CNC'd, but there is always variation.

Put it like this: Your typical HOTcam is a 220/230. How does a 214/236 sound? Maybe a 226/224?

Just food for thought, and might be worth checking for your own information. It also might be the reason some cars "like" different cams more than others .

First step is to get someone who knows what the heck they are doing, and your next steps will be to get a billet core and have it Cam Doctored.

Ryan

 

I find it almost impossible to believe that a company like comp would "average" off on advertised duration.

Isn't most of the machinery that makes this stuff completely computer controlled. IE, punch #'s in, insert core, and machine grinds away?

I can see an occasional screw up due to input error (you get a cam card, so that shouldn't be an issue if you check) or a machine being a bit off in tolerance..

But average off the shelf being off 2-6*? Uuuuh.

 

I degreed my cam and the intake opening was right on. I decided to check the intake closing and found it was off 5* (late). I checked and rechecked and was confident in my readings. I then checked #6 cylinder because it was easy to do and found that the lobes were out of phase with #1 by about 5*. I then checked all the other cylinders and the range of variability between cylinders was 6*. I got a new cam and it was within 1*.

The moral of the story is: DEGREE YOUR CAM, DON'T TAKE ANYTHING FOR GRANTED!!!!!!!

Jim

 

Who offers that service? I think a Cam Doctor would be far easier and more reliable method of checking the cam but who has a Cam Doctor? Also, you still need to check it in the motor because the cam isnt the only machined part that could throw off timing.

 

So does anyone have a degree'ing kit I can rent off them? Summit's $80 kit is backordered to March 5th...

Also, don't you need a solid roller lifter to do this, even w/ the heads off the car?

 

No, you don't need a solid roller if you're doing it with the heads off. I just took one of my old GM roller lifters, popped out the spring clip and reversed the pushrod seat so that it stuck up above the lifter body and made a nice flat surface to get a read with the dial indicator.

You really don't need the whole kit to do this. I just use a degree wheel and a dial indicator with a magnetic base and various indicator fixtures that I have around the shop to set it up square to the lifter. I bet you can buy the degree wheel at most any speed shop around WPB, and you can get a dial indicator, mag base and other fixtures pretty cheap at Harbor Freight. I think there's one of their retail stores in Riviera Beach. This is the kind of stuff you need to own if you plan to keep working on cars and if you take care of it, it will last you a lifetime.

Chris
Chris

 

True, just checked Harbor's site and they have a magnetic base and decent dial indicator for about $20.

Just need to fab up a piston stop and see about picking up a degree wheel locally.

Since my heads are off it's going to be a bitch to swap cams w/ no compression to fight against to remove the hub and crank. I need to see about getting a flywheel locking tool.

Thanks cehan Do you ever visit pbfbody?

 

The term "degreeing" has diffferent meanings depending on context. It can mean just checking, to be sure the cam is ground correctly and that the install was done correctly or it can mean setting the ICL to a specification. Obviously, to do the latter you need an adjustable timing set, not a stock or stock type LT1 set. IF you trust that the cam was manufactured correctly and that you installed it correctly, you could argue that it's redundant on an LT1 with a stock timing set. But in theory, it should still be checked. As far as my own point of view, it has evolved and now I would say check it no matter what. Obviously, with an adjustable timing set it becomes more important to check to see that you are getting it installed where you want it.

Rich