I am getting ready to install my new LE2 HC package with a cam spec'd by Bret Bauer. My question is, do I have to degree the cam? or is it ok as is to install straight up in my otherwise stock LT1?

Thanks in advance

 

You should degree the cam, check piston to valve clearance, and pushrod length.

 

You should 100% absolutely check / degree the cam when installing.

Don't half *** like most people do, this is one of those things that separates the fast cars from the "I wonder why my car is slow" cars.

 

That was my plan, but didn't want to do something for nothing.
Thanks for the quick response.

 

Is there a guide or something how to degree a cam without removing the heads?

 

Most camshaft degreeing kits will at the minimum come with instructions on how to do it.

Most will also come w/ a video.

 

For sure degree it. First time I ever degreed a camshaft, I did it the ICL method, with the heads on, engine in car, and it took no more than 40 minutes, start to finish, including building a spacer(Could use washers?) to hold the degree wheel out far enough that it wont hit the accessory bracket.

When I did mine, I was within 3/4 of 1* each time I checked it, at .005, .010, and .020 before and after peak lift on the intake lobe for number one.

 

Two other questions;

1) I'm planning on using a stock LT-1 timing set, which does not have alternative keyways cut into it to retard or advance the cam, is it essential to use an aftermarket cam gear to be able to make changes to the timing if problems are found when degreeing the cam?

2) With that said, if there is a discepency in the final cam timing other than that which is identified on the cam card, what steps are typicaly taken to fix the issue? I guess the timing set installation would be my first suspect and then possiblley the actual timing set as manufactured. Opinions?

 

Be careful when you advance or retard the cam. First.... what year is your car (vented or unvented Opti)? It throws the ignition and injector timing off, because of the way the nose of the cam drives the vented Opti. If you offset the cam sprocket, you change the position of the cam relative to the crank, and that means the Opti low resolution pulse signals are no longer correct relative to the crank rotation. With the unvented Opti, the cam sprocket drives the Opti via the splined shaft, so it has a different impact when you move the sprocket relative to the cam.

 

Bryan @ PCMforless stated otherwise on this note.

I moved my cam 2* over to *correct* it. He stated this would not be a problem, and my tuning was not adjusted for it.

Based on my results, I'd say he was correct.

 

If the cam timing is off, wouldn't you want to offset the cam sprocket relative to the crank sprocket to correct for that? Now if you adjust the cam timing by using an adjustable cam sprocket, I agree that you will throw off the low res pulse signals, but if you use an offset key in the crank sprocket, if seems to me that the ignition timing relationship to the cam position will not be affected and you will bring the cam to its correct relative position with the crankshaft.

When I degreed my cam, I found it to be 2* retarded so I installed a 2* offset crankshaft sprocket key which brought the cam timing spot on. And, just as Javier said, PCMforless agreed that this was the proper method to correct the cam timing.

 

As an experiment, I tried the following timing sets on my LE2.2 setup. The experiment was to see if the inconsistency was in the cam grinds, the timing sets or both;

$68 GM Racing Single .220 roller chain - dead on
$90 Jegs Billet double roller w/torrington - 3Deg retarded
$34 Cloyes Street Roller - 4Deg Retarded
$40 Stock GM Vortec Roller - dead on
$105 ProGear Billet/Heat treated/black Oxide Coated .250 Single Roller - 6 Deg Retarded. (nicest looking/fitting piece BTW)

Moral of the story: Degree your camshaft, I used the crank gear to dial mine in. We had no issues tuning it afterwards either.

*CompCams website is one source for directions*

 

On the Pro Gear did you make sure it was on the correct keyway on the crank gear? I've switched to these because I have never had one off when all the other ones are off.

The cams can be ground with the correct ICL in them and usually when you check the timing the part that is off is the timing chain, NOT the cam.

Degreeing the cam is doing it right, it's more to check that the install, cam and TIMING chain are correct. There is tolerance stacking in ° here so it's very easy for something to be off.

Bret

 

I was real surprised how far it read off. I grabbed our machinist to verify what I was seeing. He said I was crazy, that we never have these come in more than 1-1.5 degrees off AT MOST. He checked and rechecked again, looked at me and said, " I guess I owe you that beer!" That said, we now use these in almost every build that is a street or street strip build. The A.S.A., A.R.C.A. and NASCAR Racecar series crate engines all get the GM Race unit. They are spec'd that way and seam very durable. Even after the springs and rings have given out, the chains are still tight. FWIW.

Travis

 

Good to know it's not the norm for you either! I would just call them up and get a replacement I'm sure they would want to know about that over at Avon.

Bret