How important is degreeing a cam?
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 7,391
Likes: 3
From: Chandler AZ
How important is degreeing a cam?
Why can't you just slap it in with a 0 offset bushing and go from there then time it to factory settings? Is it hit and miss? Are manufacturers occasionally really that far off?... or is degreeing a cam just to check and make sure? Do higher lift cams require different base timing settings? What does retarding the cam (up to 4 degrees with bushings) do to horsepower/torque curves? Let the learning begin :yesnod:
Melting Slicks
Joined: Aug 2001
Posts: 2,047
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Re: How important is degreeing a cam? (billreid1@***.net)
Bill, advancing the cam from a "centerline" of 110 degrees to 108 degrees will increase your low end torque. Conversely if you retard the cam from 110 degrees to 112, it'll increase peak power a little. I would never believe anything on a cam card unless I verified it myself. It seems tooooo easy to print numbers on a piece of paper or card.. and it takes waaaaay too long to tear down a motor. Double checking is the way to go. From my experience, I bought a ZZ9x cam from TPIS a couple years ago for an LT1 car. While it was apart, I verified the intake valve centerline to be off 3 degrees from what the card said! Does 3 degrees make that much difference? You bet. The whole dyno curve would be shifted substantially. But then again.. ask yourself, how did they determine what centerline was appropriate? Then throw in lobe separation angle. It goes on and on. There's no easy answer. I'd recommend posting in the "Engine Mods" section with a crazy title. You'll get tons of responses!
Go Fast
Joined: Jan 2002
Posts: 1,691
Likes: 92
From: Colorado Springs CO
Re: How important is degreeing a cam? (EricVonHa)
EricVonHa, I'm going to be installing a hot cam in my LT1 when it warms up. I have been thinking of degreeing the cam to verify the setting. Unfortunately I can never understand how to do it even after reading it in a magazine. I consider myself fairly engine smart but cant get the degree procedure down. Is there somewhere I can go to learn how to do it? Thanks
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[Modified by Bgreenard, 12:20 AM 2/16/2002]
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[Modified by Bgreenard, 12:20 AM 2/16/2002]
Race Director
Joined: Sep 2000
Posts: 17,298
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From: The Top of Utah
Re: How important is degreeing a cam? (billreid1@***.net)
If you're going to install the cam, "as ground", you don't need a bushing.
Ninty nine percent of the cams installed, never get "degreed". Probably 95 % don't need it. But unless you degree it YOU will never know what you have. Would you install main and rod bearings without verifying the clearences? It is the builder/installer who is ultimately responsible for the suitability of the parts used in a project.
Ninty nine percent of the cams installed, never get "degreed". Probably 95 % don't need it. But unless you degree it YOU will never know what you have. Would you install main and rod bearings without verifying the clearences? It is the builder/installer who is ultimately responsible for the suitability of the parts used in a project.
Melting Slicks
Joined: Aug 2001
Posts: 2,047
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Re: How important is degreeing a cam? (Bgreenard)
For info on doing "the procedure", I'd hunt around on various Cam company web pages (Crane, Comp, Isky). I could fax you a couple pages that I have from a Comp Cams install guide from many years ago. All of my math has been handwritten on the pages from years of building stuff and using the same old documentation.. It's ugly, but I think it's still legible. Using a good "dial indicator" with a very strong magnet base is a good idea. Buying a cheapo from Summit racing or other will only cause you frustration. You know what they say.. you get what you pay for. One thing that I would swear by that I've really never seen purposefully written into any "how to" documentation in degreeing cams is that no matter whether you're starting a sequence, make sure that the motor is turned over one complete full revolution to take out any timing chain slack and allow the lifter to settle in it's natural travel pattern. I can't say that you'll be "off" if you don't go a full rev, but it only makes sense.. Let me know, I'd be glad to copy it and fax it.
