Importance of Degreeing in your Camshaft

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Truckedup
Guru
Guru
Posts: 2728
Joined: Mon Jan 21, 2013 2:41 pm
Location: Finger Lakes

Re: Importance of Degreeing in your Camshaft

Post by Truckedup »

So you all use X degrees at .050 lift and not lobe centerline?
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
statsystems
Guru
Guru
Posts: 1508
Joined: Sun Apr 03, 2016 1:17 am
Location:

Re: Importance of Degreeing in your Camshaft

Post by statsystems »

I don't. I centerline cams because you can have a cam that will centerline in different places with the same at .050 reading.
Truckedup
Guru
Guru
Posts: 2728
Joined: Mon Jan 21, 2013 2:41 pm
Location: Finger Lakes

Re: Importance of Degreeing in your Camshaft

Post by Truckedup »

statsystems wrote: Sun Jul 08, 2018 2:22 pm I don't. I centerline cams because you can have a cam that will centerline in different places with the same at .050 reading.
I use centerline on the race bikes for the same reason...And it just seems a better reference point to me ...
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire
User avatar
woody b
Guru
Guru
Posts: 2030
Joined: Thu Jun 27, 2013 6:58 pm
Location:

Re: Importance of Degreeing in your Camshaft

Post by woody b »

I had a couple belt drives marked 1 tooth off a few years ago.
I used to be a people person, but people ruined it.
plovett
Expert
Expert
Posts: 871
Joined: Sat Dec 30, 2006 3:49 pm
Location: Kansas City

Re: Importance of Degreeing in your Camshaft

Post by plovett »

Walter R. Malik wrote: Sun Jul 08, 2018 11:42 am
plovett wrote: Sun Jul 08, 2018 11:27 am I've only degreed a few cams. All of them were off from where I wanted them when installed dot to dot. I had one that I had to advance 8 degrees to get it close to where I wanted it! I think it's important to check.....even though it is true I am just guessing at the best installed location.

JMO,
paulie
Checking where the camshaft is timed is important to know, especially with all the tolerance stack-ups which are there.
One reason is because it may not be NEAR where you would like it to be; (whether right or wrong) you know where it is.
Yes. At least you have a known reference point.
swampbuggy
Guru
Guru
Posts: 1572
Joined: Mon Apr 04, 2011 8:54 pm
Location: central Florida

Re: Importance of Degreeing in your Camshaft

Post by swampbuggy »

Locating "ABSOLUTE" top dead center of the number 1 piston has to be step number one !!! :wink: Mark H.
geraldtson
Member
Member
Posts: 129
Joined: Tue Feb 10, 2015 9:50 pm
Location:

Re: Importance of Degreeing in your Camshaft

Post by geraldtson »

Don't get complacent. Degree it. Come troubleshooting time you'll be glad you did.I have just about give up on reliable or honest cam SELLERS. If you find one that works for you, you should appreciate them and stick with them. To many are just after your credit card number and know that most of the time your not gonna check it and don't have time to do the whole return deal. Last three SBC in a row ( two custom and one shelf) were all off beyond reason. I'm not concerned about price at all but if i specifically ask for 8620 billet and no pressed on cast distributor gear and seller says thats what i'll get, it really hurts when you open the box and find out they lied on both counts.
I do however believe there are probably a couple of good sources here that frequent this forum that care about what they make and or sale!
Someone once said "9 times out of 10" camshaft will be fine but it's the one time you don't degree it you'll regret it!! Degree it.
Walter R. Malik
Guru
Guru
Posts: 6340
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

Re: Importance of Degreeing in your Camshaft

Post by Walter R. Malik »

Here's one I will never forget ... a BUICK 430 V8 flat tappet cam which was exactly 3 camshaft degrees, (6 crank degrees), off between engine banks. And, then that large southern California camshaft company would not give me a cash refund but, would send me another cam.
That newer cam was also off 3 cam degrees the same way, obviously they didn't KNOW the correct lifter bore "bank to bank" angle ... sent that one back and they would merely give me a credit for a different cam, insinuating that I didn't know what I was doing. Apparently, big block Buick cams from them had merely been installed "Dot to Dot" with supposedly one side advanced 3 degrees and the other side retarded 3 degrees.

I then got a cam from TA Performance and "lo & behold" it was correct.

I have never done business with that first camshaft company again ... after 30 years, they still have my credit.
http://www.rmcompetition.com
Specialty engine building at its finest.
GerryP
Member
Member
Posts: 75
Joined: Tue Apr 06, 2010 10:26 am
Location:

Re: Importance of Degreeing in your Camshaft

Post by GerryP »

Walter R. Malik wrote: Sun Jul 08, 2018 7:27 pm Here's one I will never forget ... after 30 years, they still have my credit.
You, sir, know how to hold a grudge. My wife would like to talk with you. :-}
geraldtson
Member
Member
Posts: 129
Joined: Tue Feb 10, 2015 9:50 pm
Location:

Re: Importance of Degreeing in your Camshaft

Post by geraldtson »

Just returned a SBC cam to camshaft company in california. 1st thing i told them when ordering camshaft was if the base circle came in at .850 i was gonna send it back.Thats not what i wanted but what i was trying to get away from. He said it would probably come in somewhere around .930 or so. Sounded fine to me. Took it out of box and it measured .856. I called they said no problem i could have store credit for another cam. I said no and sent it back for full refund because i could sense i was digging myself a hole. Think i may have just got the wrong guy on phone. Some will listen some dont care.
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: Importance of Degreeing in your Camshaft

Post by MadBill »

CGT wrote: Sun Jul 08, 2018 1:42 pm
MadBill wrote: Sun Jul 08, 2018 1:10 pm Be very interested to know how far off a Jones index recommendation has been for you CGT, and the specific effects of optimizing it.
The most drastic of mine was a i believe 231 234 108 roller in a 383 chevy. Recommend icl 104. It ran good there, and if you never tested any other position you wouldnt have known there was 30+hp moving back to 108. It interestingly enough, lost a bunch of power retarding it back even further to 112.
Wow!
A theory that I find plausible is that the closer to 'ideal' a cam's ground-in events are, the bigger the effect of sub-optimal indexing, because rather than one or two events being bettered by the change but the others worsened thus cancelling each other, with the optimum cam everything gets worse either way from the happy spot. Thus if +/- say 4 degrees doesn't do much, chances are the cam specs are less than ideal.
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
statsystems
Guru
Guru
Posts: 1508
Joined: Sun Apr 03, 2016 1:17 am
Location:

Re: Importance of Degreeing in your Camshaft

Post by statsystems »

MadBill wrote: Sun Jul 08, 2018 10:41 pm
CGT wrote: Sun Jul 08, 2018 1:42 pm
MadBill wrote: Sun Jul 08, 2018 1:10 pm Be very interested to know how far off a Jones index recommendation has been for you CGT, and the specific effects of optimizing it.
The most drastic of mine was a i believe 231 234 108 roller in a 383 chevy. Recommend icl 104. It ran good there, and if you never tested any other position you wouldnt have known there was 30+hp moving back to 108. It interestingly enough, lost a bunch of power retarding it back even further to 112.
Wow!
A theory that I find plausible is that the closer to 'ideal' a cam's ground-in events are, the bigger the effect of sub-optimal indexing, because rather than one or two events being bettered by the change but the others worsened thus cancelling each other, with the optimum cam everything gets worse either way from the happy spot. Thus if +/- say 4 degrees doesn't do much, chances are the cam specs are less than ideal.
I totally agree. If you move a cam 2 degrees either way and you pick up power the grind is wrong and you are leaving power on the table. Seen this on the dyno and the track so many times I can't count them all.
BigBro74
Expert
Expert
Posts: 555
Joined: Mon Sep 06, 2010 7:48 pm
Location: Mid Illinois cornfields

Re: Importance of Degreeing in your Camshaft

Post by BigBro74 »

I have seen the timing sets be wayyyyy off a bunch of times- the cams are usually (but not always) much closer. The timing sets made me never want to just put a cam in on the Marks without checking again
Warp Speed
Guru
Guru
Posts: 3264
Joined: Wed Jun 25, 2008 1:46 pm
Location: NC

Re: Importance of Degreeing in your Camshaft

Post by Warp Speed »

statsystems wrote: Sun Jul 08, 2018 10:49 pm
MadBill wrote: Sun Jul 08, 2018 10:41 pm
CGT wrote: Sun Jul 08, 2018 1:42 pm
The most drastic of mine was a i believe 231 234 108 roller in a 383 chevy. Recommend icl 104. It ran good there, and if you never tested any other position you wouldnt have known there was 30+hp moving back to 108. It interestingly enough, lost a bunch of power retarding it back even further to 112.
Wow!
A theory that I find plausible is that the closer to 'ideal' a cam's ground-in events are, the bigger the effect of sub-optimal indexing, because rather than one or two events being bettered by the change but the others worsened thus cancelling each other, with the optimum cam everything gets worse either way from the happy spot. Thus if +/- say 4 degrees doesn't do much, chances are the cam specs are less than ideal.
I totally agree. If you move a cam 2 degrees either way and you pick up power the grind is wrong and you are leaving power on the table. Seen this on the dyno and the track so many times I can't count them all.
That depends on where in the rpm range you want the power. Typically, you want the most power between the peaks. Some combos/people will favor more low end, below peak torque. Others will give up some peak torque for added power due to the rpm being run. When a cam is optimum between the peaks, moving it forward typically increase torque below peak (earlier intake closing event) while maybe adding a little peak torque at the expense of peak power. In this scenario, you may actually improve some after peak power due to the earlier opening exhaust, even though it lost at peak. Moving it farther forward can increase output below peak torque, but peak torque will start to drop also, while peak power is dropping fast.
Kinda the opposite retarding. You will start to loose peak torque in exchange for peak power. Moving farther the engine will quit gaining power, but still lose torque. Eventually both will fall.
Ken_Parkman
Expert
Expert
Posts: 660
Joined: Sun Jan 02, 2005 11:30 pm
Location: Ontario, Canada

Re: Importance of Degreeing in your Camshaft

Post by Ken_Parkman »

Had one come to me where the car could not run the number. Had been through 3 owners because it could not run the number. Finally pulled the engine to find out what was wrong, and found the cam 23 degrees out, but the dots were lined up. This engine config had no piston to valve clearance issues. Fixed the cam timing and it was running on the class record.

The troubleshooting comment is so true. Chasing underperforming combo's I've made tooling to check the cam timing in the car - it's a real pain.

I ALWAYS check, and am perfectly happy when it is a waste of time.
Post Reply