can someone tell me how to degree a cam. im getting most of my stuff ready for this project and i need to kknow how to do it. or even if someone has a link that will tell me how. that would be great also

or if someone wants to come down here and do it for me (free of charge) that would be ok to.

 

Keep in mind that for all practical purposes, the cam in an LT1 must be installed "straight up". The proicedure for degreeing it though is the same as any other pushrod OHV engine. A good description can be found in Comp Cams catalog or on their web site. http://www.compcams.com/catalog/022.html

They also have a nice video: http://www.compcams.com/store/mercha...oduct_Code=191

BTW: this is not easy to do in a 4th gen with the motor installed!

Rich Krause

 

Yeah, degreeing a cam in an LT1 should only be used to check the cam to the spec card.

If you want the cam degreed differently you should have it ground in.

 

yes the engine will be in the car so i guess im in for it. but im going to do one next wed. the engine is out of that car. so it needs to go striaght up huh. and yes it will be a custom grind. i want a 230 236 but i want the lift as if it had 1.6s on it. so it should have a 544 lift but want it ground to where its has that lift with 1.5s so i can put 1.6s on it. that would give me a 580 lift on the exhaust. and im think about making it a 230 240 adding 4 degrees on the exhuast side.

what do you think that would do.

 

LOL i wouldn't mess with that stuff unless you want it to run like a piece of poop! Why don't you just get it ground differently and stick 1.6rr's on it? Or just live with the specs it has until you get them.

 

im curious what makes you think it will run like crap.

 

Degreeing the cam in an LT1 as Kevin mentioned is only good for verifying the cam was ground correctly.

Using offset bushings or offset crank key will result in the optispark being off in relation to the crank. Then that will affect your timing and your injector firing.

Makes for difficult if not impossible to tune. Professional tuners have commented on this.

If you want, verify the cam is ground correctly with a degreeing kit and if not ground correctly then return it and have one custom ground AND Verified at the manufacturer. It costs a little more but it ensures you get what you want.

DaveW

 

Hate to bring the dead posts up, but i didnt want to start a new one. So, if my intake centerline is at 101 and supposed to be on a 108, I must get the retard ground into the cam? Cant use bushings or anything else?

I have the LT4 Extreme Duty chain with an oversize crank sprocket.

The motor is out of the car and no heads on it yet. Whats the proper way to degree this sucker in? i have a stop on the deck surface of the block for TDC. that link that rich gave doesnt really help hehe.

it would amaze me if the cam is that far off since the cams are made by CNC.

Anyways, if it does prove to be still off that much even with trying my old stock chain , then must i send the cam back to comp and have them grind in the 7 degrees of retard?

 

Perhaps because you didn't turn to page 23 to finish the degreeing instructions? I have never done one, but all the needed info is there.

 

The piston can't really be at TDC with a stop there. The stop is only there to figure out where TDC is, then you remove the stop and put the piston at TDC.

Since the cam pin drives the distributor on 95+ cars, you cannot change the cam phasing without disrupting the ignition timing. That's the main reason why you have to have it ground in. However, you might possibly be able to have a pre-'95 cam gear machined to allow you to adjust the cam timing using traditional offset bushings. But then you'd have to run the older style optispark and timing cover.

-Dave C. '97 Z28

 

Since this thread was resurrected, I'll make a couple comments regarding the often misrepresented and misunderstood term 'cam degreeing'.

Checking cam timing, (or cam timing to piston relationship) and degreeing a cam are not one and the same. From my POV, checking the cam to crank timing is just what it says. Degreeing is actually doin' somethin' about it, NOT just checking the timing.

OK, some say don't change/correct the crank to cam relationship, cuz it will change the opti/injector timing. Yes, it will. Note I stated CHANGE, not UPSET. How do you know it is correct the way it is now? When you check (NOT DEGREE) cam timing, (in an assembled engine) you are NOT just checking how accurate the cam was ground, or more important in this discussion, the cam timing to crank relationship. If you were, and the cam to dowel relationship were correct, then ya, you will change (for the worse) the opti/injector timing. Like I stated, you are not. You are actually checking the entire assembly. You are checking the crank key slot, the crank gear, the cam gear, the cam gear to cam connection, cam timing to dowel relationship, and FINALLY the cam timing itself. Different components (the ones listed) can be off any amount, but if they cancel out each other, and the cam to crank relatonship winds up dead nuts, who cares? Well, in the pre LT1 era, one wouldn't need to care. You see, now, even if the cam to crank timing relationship were acceptable, the opti/injector timing could STILL be off, IF the cam dowel is out of location, although it is unlikely, using the dowel to locate from, when grinding the lobes.

Bottom line here, I check the crank to cam timing relationship, and if it is off, degree it by any means feasible. You see, I'm banking that the error (or errors) in the assembly are in any of the components other than the cam to dowel relationship. If I am correct in my assessment, I'm home free, for I am not now upsetting the opti timing to crank relationship, but correcting it. If not, and this can be verified with timing light on the hub/dampner crank and a known stationary point, similar to pre pcm days, I'll need to alter the dowel to opti position whatever amount showed up with the timing lite.

Alot of work to correct cam timing? What would the effort to result ratio be? This is one of those cases where good judgment needs to be exercised. If the (assembly) timing is off a degree, no, not worth the time. But, if it is off 3-4*, I believe it to be worth the effort. Now tell me, did someone actually understand me here?

 

degreeing or checking, all semantics. Same difference imo.

hows 7 degrees off on the ICL for ya? LOL!

no wonder the car was a bitch to start and why it wouldnt run. and why there was no top end.

 

Degreeing is intended to correct the timing relationship of crank to cam, not to correct improperly ground cam. When degreeing, IF the cam itself is correct, the intake and exhaust obviously will be off similar amount. Anything done to correct a improperly ground cam will help one (int. or exh.) and hurt the other.

It would amaze me if the cam is that far off since the cams are made by CNC.

The cnc operation should not be off. The equipment will spit out based on what is programed in. Sounds like a human error to me.

Anyways, if it does prove to be still off that much even with trying my old stock chain , then must i send the cam back to comp and have them grind in the 7 degrees of retard?

As noted above, new chain, old chain, the entire cam timing (int. open/close and exh. open/close) will be off similar amount, with the correct exh./int. timing relationship.

I wouldn't monkey around doctoring that cam, I'd request a replacement. The quality control apparently broke down. I hope CC makes good. Language filter must be broke, aye?

 

I already sent it back to comp. Bastards made me pay shipping for their mistake. what kind of **** is that?

As you probably know, with the intake centerline being off, the exhaust and/or lsa must also be off too.....

 

Ok guys I guess I did not completely understand this.

I just went with a solid roller Comp cams and when I installed it straight up the centerline was 110. They said it should be 108 so since I used a Cloyes true roller chain I advanced the bottom crank gear 2degress. Checked the cam again and the #s were dead on it. I have changed many cams in this motor and I have never had 1 cam dial in straight up. so are you guys telling me that I should go back and put it straight up? I tune the car myself so if tell me your opinions on what to do. Also if your saying that its just changing the igniton timing then why can't you just slot the opti bolt holes and adjust the timing that way or do it in the tune?