How to Guide: Degreeing Cams on 6G72 w/ Pictures

[familyMAN]

Good point. I understand what you are saying. I'm stating "zero" as to the cam card recommendation. You would think webcam would have a reason to set them to 110.

I'm even more motivated to try different settings now on either dyno or VD.

[RealMcCoy]

Take a look at the BC Cam Card, the note states set to "0" and then tune from there for best result, well 0 is 109.5 in/106.5 ex for us....BC could have reccomended 1XX in/ex but that wouldn't be zero (0) on our cars...Just to clear up any confusion here is the math from the BC Cam card to show the BC cam "0" is the same as our cars ((180+7+31)/2)=109 CL intake ; ((180+1+33)/2)=107 CL ex...

Agreed, but other cam grinders may not be on the same center... If they're using new blanks, they could put the centerline wherever they wanted.

If they wanted 110 centers. They could just use N/A blanks and grind them 1/2 degree off... I wouldn't assume ALL cams are on stock centers.

[Italo Grasso]

Agreed, but other cam grinders may not be on the same center... If they're using new blanks, they could put the centerline wherever they wanted.

If they wanted 110 centers. They could just use N/A blanks and grind them 1/2 degree off... I wouldn't assume ALL cams are on stock centers.

Ummm. CL can be moved where ever you like and the only reason for a cam manufacturer to move it on this application is if they assume the buyer does not have adj cam gears..either way ( wether you move the CL with adj cam gears or by grinding) it still is not the zero for our cars unless it is at 109...106....

[oohnoo]

I could be wrong but I think your missing the fact that the cams themselves could be off, that's why you degree them finding the center of the cab lobes, not "ASSUMING" they are cut correctly. I remember Ray saying that BC cams are junk and that he's never had nothing but trouble tuning with them and removes them from any car he builds. I attached the cam card for mine.

Take a look at the BC Cam Card, the note states set to "0" and then tune from there for best result, well 0 is 109.5 in/106.5 ex for us....BC could have reccomended 1XX in/ex but that wouldn't be zero (0) on our cars...Just to clear up any confusion here is the math from the BC Cam card to show the BC cam "0" is the same as our cars ((180+7+31)/2)=109 CL intake ; ((180+1+33)/2)=107 CL ex...

[Italo Grasso]

I could be wrong but I think your missing the fact that the cams themselves could be off, that's why you degree them finding the center of the cab lobes, not "ASSUMING" they are cut correctly. I remember Ray saying that BC cams are junk and that he's never had nothing but trouble tuning with them and removes them from any car he builds. I attached the cam card for mine.

Hey bob, doesn't really matter how off the cams are..if you degree any cam to our zero..109/106 then you have a reference point inwhich you can adv or retard them to what ever you want..right now your cams are degreed to a recommended 110 intake and exhaust you could easily move them back to zero with a little math...degreeing just gives you a refrence point until you tune for best results..my brother is running these BC 272
after we degreed them and they seem to be kicking ass..

[RealMcCoy]

Ummm. CL can be moved where ever you like and the only reason for a cam manufacturer to move it on this application is if they assume the buyer does not have adj cam gears..either way ( wether you move the CL with adj cam gears or by grinding) it still is not the zero for our cars unless it is at 109...106....

The centerline is wherever the cam grinder puts it... What came in the car originally is inconsequential and irrelevant. Having four cams, we actually have the luxury of deviating from the manufactured settings... If I buy a cam for an LS motor that's on 108 centers, I'm certainly not going to cry about it not being on the factory 114 degree centers, I'm going install it and degree it to where the cam grinder says it belongs, and hope they know what they are doing...

[Italo Grasso]

The centerline is wherever the cam grinder puts it... What came in the car originally is inconsequential and irrelevant. Having four cams, we actually have the luxury of deviating from the manufactured settings... If I buy a cam for an LS motor that's on 108 centers, I'm certainly not going to cry about it not being on the factory 114 degree centers, I'm going install it and degree it to where the cam grinder says it belongs, and hope they know what they are doing...

Sorry i disagree..for this discussion the original cam Cl's is very consequential and relevant as the discussion is about best perfomance with +1-3 cam settings from (zero)109/106. Consider this example, if you were to install the recomended 110 cam CL from the cam manufacturer then move them +1 -3 the resultant CL's would not be what chris has tested to yield best perfomance in all cams he has tested. Do you agree? So Now regarding your LS example I would agree that having the manufacturer move the CL's during grinding is critical for LSA/overlap..etc...as the in/ex on that single cam shaft is fixed, but it would be silly to think that the recommend install CL is always the best perfomance...i would bet that if you put that on a dyno and retard/adv the cam as you tune you will find the sweet spot depending on your setup and where you want your peak power output..

[J. Fast]

I think you and McCoy are saying the same thing Grasso. If you set to 110 centerlines you will not have the same valve timing as if you set your cams to stock centerlines and then adjusted the valve timing to +1, -3. You both are reitierating that MFR and OEM specified centerlines may not always be were you want peak power output. We're free to change the centerlines as a matter of preference and performance.

You did make a valid point regarding what works for one may not work for all. If I recall Chris is also not running a traditional I to E lift ratio so his results are also going to be skewed from the norm. Each setup is unique.

When it comes down to it you really cant make any blanket statements about what cam timing is ideal becase the real intention of the adjustment is to control the air to fuel ratio. That all changes when you increase or decrease temperature, humidity, and barometric pressure.

[RealMcCoy]

The setting that yields the highest peak power may not be the best setting for midrange and low end torque.... Using Bob's street cams as an example: They are ground for 110deg centers... Be it wrong or right, that is where the cam grinder manufactured them... If you put them in a stock car, with stock gears with stock deck height, they would very likely be very close to the manufactured settings of 110 degrees. So what does the stock cam's settings have to do with that whatsoever...? If Bob decides to try moving them around to see what gains can be had, he knows where they are. If he wants to try 108/103, he knows he can just move his exhaust cams back 7 and his intakes up 2... Why would anyone care about how far you moved them, if you aren't using cams with stock centers?

I think we're saying pretty much the same thing, we just have a different perspective on the significance of the factory settings... In my opinion, if you want to work with cams that have stock centerlines, buy cams with stock centerlines... Otherwise just know the specs of your cams, and adjust accordingly if you want to deviate from the manufactured specs.

[Ninja Performance]

So Bob,
You used the Adjustable cam gears set at 0 to degree the cams and find out how "off" they were either due to the manufacturer or the mill on the heads etc? Then added that difference to the adjustable gears?

If so, I am still wondering if the gears are perfect, if they are not 0 when set to 0, then I wonder how "off" the cams would have been if you used OE cam gears to find where they needed to be set.

Not that it would matter.
Just would be interesting to know.

-Chris