I've got the heads/cam in but still have a ways to go (mount opti, intake etc) but a friend of mine asked "Did you degree the cam?" and I was like huh? Can you degree the hot cam or any cam for that matter on the LT1? I figured since it had the dowel pin, and once the timing is set correctly, you can only install it one way. Am I wrong on this?

 

If you use the Cloyes timing set you can do it.I would leave it straight up.

 

So I DO have to degree the cam??!??? I'm using the LT4 HD timing chain set. I pretty much put the cam in the way the other one cam out. Do I need to pull the car back apart??!???!

 

No you dont have to.The only advantage is increasing high and low eand torque depending which way you go.Like I said,I would leave it at factory spec.

 

as long as the dots were lined up you have it in straight up which means your fine

i am planning to degree my hot cam as well and from a time stand point it is well worth the 30 min. it takes to do it

 

The ignition timing will be off if the cam is not installed "straight up", with the dots aligned. That's because the distributor (Opti) is driven off the cam dowel. You can still "degree the cam" in the sense of checking to see if it's ground correctly, but don't try to install it anything other than straight up unless you want to do major alterations to the timing tables.

Most LT1 cams have 4 degrees of advance ground into the cam, BTW.

Rich Krause

 

There appears to be some confusion as to what constitutes 'degreeing a cam'. It has little to do with bolting in the cam 'straight up'. What is being accomplished is insuring the correct valve opening to piston position relationship .

The intent/purpose of degreeing is to eliminate/correct any tolerances machined into relevant parts in the crank/cam drive mechanism. This includes: keyway in crank and crank gear, cam gear to cam locating points, and yes any tolerances ground into cam itself. BTW, if the crank to cam relationship is 'off', without checking cam by itself, outside of engine, it would not be possible to determine how much of total error is in cam and how much is in crank/cam drive mechanism. Chances are, the cam itself will be ground respectfully close. Yes, anytime, one changes the cam to crank relationship, it will affect opti timing. However, if this relationship is off, (via the drive mechanism) you will CORRECTING, not hurting opti timing by the degreeing procedure, because, if the cam is off, so is the opti. How one alters/corrects this out of time dilema in an LTx engine, is restricted to an offset crank keyway. The traditional sbc can be altered via keyway, as well as offst bushing for the cam gear drive dowel. Not saying the opti drive pin is guaranteed accurate, but in the case of the LTx engine, it is probably better to maintain the oem cam to opti relationship.

SHOULD this procedure be performed? Well, it is a good idea to at least check the crank/cam relationship in any performance application. If the engine is worth the cam change, it deserves to have the timing relationship checked as well. SHOULD the problem be corrected? Well, that depends on how far off it is. If it is a couple of degrees, ??. Will it matter? With track times the recipient, sure. But in your average performance street vehicle, one probably won't feel the diff.

 

I agree with arnie that 'degreeing' = 'verifying'
[not advancing/retarding] cam timing..

 

No need to do this on these cars, unless the crank gear you used has multiple positions and you are not sure if you put it on correctly. What I did with the Cloyes double is just compare the crank gears of the two sets, and the dots, to see which one I was supposed to use. The stock position for the crank gear is simply the rectangular slot.

Line up the dots with #1 at TDC and thats it. Just make sure your gears are 6/12, if they are off by even 1 tooth it should be obvious, and that is probably somewhere between 8-15º (count the teeth and you can figure it out), regardless of how far off it is it will have a major impact on the powerband.

 

Actually, Iwas attempting to convey that 'degreeing' is the actual correction of the error, verifying is verifying. If you interpreted the post otherwise, then I misled you.

Doc, how are 'these' cars any different than any other sbc?

 

There is nothing to screw up if you follow the ABC directions, if you put the chain on correctly you are go for launch.

If you dont trust that your cam is correct, go for it. For Hotcam I dont see the need to worry, the only bad Hotcam story I've ever heard was a bad lobe. If the cam somehow is off by a single degree, what are you going to do, send it back over that? A Hotcam wont make that much power to begin with, much less will it be much different if its off by a degree. If you put the chain on incorrectly and its off 15º then you have a problem.

 

Like I referred to, above. Nothin' special 'bout the LTx. What you just stated above, applies to ANY sbc.

If you don't trust that your cam is correct, go for it.

Maybe you missed the point I stated above. Quote: "Chances are, the cam itself will be ground respectfully close". The reason for degreeeing is usually NOT the cam grinding.

If the cam somehow is off by a single degree, what are you going to do, send it back over that?

Hell no, if the assembly ( I'm stressing assembly btw) was off by a degree, leave it alone. 'Course you won't know if it is off by JUST a degree if one doesn't take the time to check it, which is part of blueprinting procedure where I come from. Again, not the cam, it's the cam drive mechanism in particular.

If you put the chain on incorrectly and its off 15º then you have a problem.

Nothin' to do with poor assembly, Doc. Sounds like the practice of degreeing cam assemblies has become a lost science. However, doesn't mean it is any less important or necessary to check/correct in performance applications. Appears we need to agree that we certainly disagree.

edit: spelling