Degreed Cam, ITS OFF, Now What?

I went ahead today and degreed my camshaft, and it is off. It is off by two degrees. How do I go about correcting this now? Please fill me in guys!

How many times did you measure? Was it the same each time? I find it difficult to make measureanments more precise than 1-2 degree. I wouldn't assume it's off unless it is consistently at least 1-2 degrees off in the same direction. 1-2 degrees off from spec, assuming it's really off, is pretty small. If you want to correct it in an LT1 you will need an adjustable timing set and an electric water pump. You will also need to change the igntion timing to compensate for the cam adjustment. Alternatively, you would need to track down where the error is, not easy when dealing with such a small amount. If it were me, I'd leave it alone.

Rich

How many times did you measure? Was it the same each time? I find it difficult to make measureanments more precise than 1-2 degree. I wouldn't assume it's off unless it is consistently at least 1-2 degrees off in the same direction. 1-2 degrees off from spec, assuming it's really off, is pretty small. If you want to correct it in an LT1 you will need an adjustable timing set and an electric water pump. You will also need to change the igntion timing to compensate for the cam adjustment. Alternatively, you would need to track down where the error is, not easy when dealing with such a small amount. If it were me, I'd leave it alone.

Rich

I mesured it about 15 times, and they all came up 2 degrees off in the same direction. I have a brand new cloyes timing chain installed, and would hate to have to buy an adjustable timing chain, whom I dont even know manufactures one for the lt1. I already have an electric water pump. Someone told me that I can run a offset crank keyway? As for compensating fot the ignition timing, wouldnt I be correcting the ignition timing, as if it were installed right now, it would be off?

Cloyes makes a Hex-a-just for the LT1. It is a double roller and the part number is 9-3145A.

I use that set almost exclusively, it is much easier than drilling the cam sprocket and playing around with different degree bushings.

cant use adjustable...im running a non vented setup..

cant use adjustable...im running a non vented setup..

Ah I missed that.

now my only choice is to run a offset crank key, but I dont know which I need 1.) Long 1 3/8" or 2.) 3/4" short

Does the cam check 2* advanced or retarded?

If advanced, that's probably not all bad. With miles, the chain will stretch a little and retard the cam slightly.

If the cam is from Bret, you might consider checking with him before you buy any parts to change the cam's location. He's away from the shop, but I think he's still checking email. He's due back in time to attend Cup qualifying at Watkins Glen Friday.

If it's not a cam from Bret, I agree with Rich; leave it where it is, especially if it's advanced.

My $.02

Does the cam check 2* advanced or retarded?

If advanced, that's probably not all bad. With miles, the chain will stretch a little and retard the cam slightly.

If the cam is from Bret, you might consider checking with him before you buy any parts to change the cam's location. He's away from the shop, but I think he's still checking email. He's due back in time to attend Cup qualifying at Watkins Glen Friday.

If it's not a cam from Bret, I agree with Rich; leave it where it is, especially if it's advanced.

My $.02

Yes it is a Bret Cam. I have tried to get a hold of him, but have had no luck. I sent him e-mails, no replies yet. Its checking in at 108, not 106. So Im guessing its retarded, because it needs to be advanced 2°..

Ya won't be able to tell a 2* change by SOTP. It won't kill it anyway ya go. Like was said if it's advanced it's a good thing

My way of thinking it should be 108* on your set up.

Ya don't want to get into the brain damage of changing the timing map in the computer and the injector timing.

Larry,

This one needs to be at 106 and not 108. Trust me on that one....

Diego,

I've talked with Lloyd when you asked him and the key and bushing are good ways to go in your case. I agree with Nick also, I only use a Hex-A-Just or a Progear TC, and obviously not non-vented optis.

I did finally just get your e-mail though.

Bret

Two degrees off on the igntion timing needs to be corrected. Two degrees on the fuel is inconsequential (pun intended).

Rich

Larry,

This one needs to be at 106 and not 108. Trust me on that one....

Diego,

I've talked with Lloyd when you asked him and the key and bushing are good ways to go in your case. I agree with Nick also, I only use a Hex-A-Just or a Progear TC, and obviously not non-vented optis.

I did finally just get your e-mail though.

Bret

Ya gonna have to change the timing and fuel map in the computer if ya move the cam.(been there) The right way is to send it back and have it re made to the right spect.

Larry, from my understanding, the cam timing right now is off, and we are correcting it, not altering it. If the dowel is off, so is the dowel hole, so when we move the dowel pin to the correct location, we are also moving the dowel hole in the correct position as well. Also from my understanding and research, we are putting everything in "sync" with eachothere, putting everything back to OEM specs how GM designed, and how the opti senses the crank position. I understand, that if we were at OEM specs and we altered (either advanced or retarded) the setup, then we might have to adjust certain tables in the pcm. But at the current moment, all we are doing is getting everything back to standard, am I not correct?

Larry, from my understanding, the cam timing right now is off, and we are correcting it, not altering it. If the dowel is off, so is the dowel hole, so when we move the dowel pin to the correct location, we are also moving the dowel hole in the correct position as well. Also from my understanding and research, we are putting everything in "sync" with eachothere, putting everything back to OEM specs how GM designed, and how the opti senses the crank position. I understand, that if we were at OEM specs and we altered (either advanced or retarded) the setup, then we might have to adjust certain tables in the pcm. But at the current moment, all we are doing is getting everything back to standard, am I not correct?


Okkkkaaaa

I think I may have figured out the problem...I was finding TDC, but not TRUE TDC. I am going to redo it when I get home with the correct tdc tool, not just the dial...Could this be the culprit?

I think I may have figured out the problem...I was finding TDC, but not TRUE TDC. I am going to redo it when I get home with the correct tdc tool, not just the dial...Could this be the culprit?

Yep.

Comp Cams Intake Centerline method is pretty good, especially using a hard stop.

http://www.compcams.com/Technical/Instructions/Files/145.pdf

Make darn sure you have a problem before you try to "fix" it.

Good luck!

The hard stop is the only way to accurately find TDC, this should help you out a ton!

Bret