Advance Keys

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Bad Sport

Bad Sport

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OK, so I have another 360 I'm toying with. I have never used the offset keys, but am wondering if/what the advantages are.

I have a Cloyes timing set with no provision to advance or retard timing.

SO, what are the performance advantages.

This will be a stock bore 360 (about 9:1 or a tad better compression), Speed Pro pistons, Comp XE268 cam, LD340 intake, factory J heads with a mild porting just for clean up,--carb undecided--.......
 
I've heard in the past that Mopars run better with the camshaft advanced a couple degrees. That's all I know. It sounded to me like it's one of those things that require a dyno and a lot of your time to maximize the gain from your cam. I don't even know how much one would gain or lose by advancing or retarding the cam. It's way above and beyond my level of the hobby.
 
Leadfoot said:
I've heard in the past that Mopars run better with the camshaft advanced a couple degrees. That's all I know. It sounded to me like it's one of those things that require a dyno and a lot of your time to maximize the gain from your cam. I don't even know how much one would gain or lose by advancing or retarding the cam. It's way above and beyond my level of the hobby.
Click to expand...

LOL, mine too, that's why I'm pickin' some brains.

I do intend to degree the cam (which will be a learning experience), I'm trying to throw something together while my other block get's some machining etc.

The Dart has become a little boring with the teen in there. :D
 
I ran my last 340 with the cam installed straight up on a 106 centerline. I advanced the cam 4 degrees to 102, it picked up noticeably in lower rpm just off idle. It revved ALOT quicker. I have another 340 in an aspen I have apart now doing a cam change and just ordered an offset cam key to advance it 4 degree.
 
from what i have read. advancing the cam 2-4 degrees shifts torque from the high end to the low end, but does not make more torque total. but it might not be a lot but must be enough to make it worth the trouble. i have done 3 engines to 2 and 4 degrees, good out come. BUT DO NOT TRY 6 degrees!!!!!!
 
I have had to us 6* key to get 2* advance...........and thats why you should degree Every Cam you install!

If this is your first time degree in a cam, make sure your not rushed and have plenty of time to perform the task. Its not hard but can be confussing some times.
 
moe7404 said:
from what i have read. advancing the cam 2-4 degrees shifts torque from the high end to the low end, but does not make more torque total. but it might not be a lot but must be enough to make it worth the trouble. i have done 3 engines to 2 and 4 degrees, good out come. BUT DO NOT TRY 6 degrees!!!!!!
Click to expand...

That's what I was wondering.
 
Years ago I built a 340 and was instructed to advance the cam 4 degrees. Bottom end torque was increased but I was not satisfied with the upper rpm pull. I went to "straight up" timing (dot to dot) and the car ran much better. I've always run the timing chains dot to dot ever since. Just my experience....
 
318willrun said:
Years ago I built a 340 and was instructed to advance the cam 4 degrees. Bottom end torque was increased but I was not satisfied with the upper rpm pull. I went to "straight up" timing (dot to dot) and the car ran much better. I've always run the timing chains dot to dot ever since. Just my experience....
Click to expand...

I usually do as well, although with the horror stories of cams being so far out in degree, I need to grab a set I guess just so I have the ability to correct it.
 
Differences in timing chain sets can also cause them to be off. A few yrs. ago I rounded up 4 timing chain sets and did a test on all of them and none degreed the exact same. The worst (a Mopar perf) was 3 degrees off from the best. Every time I've degreed a cam and a Cloyes set was used they were within 1 degree which is perfectly acceptable.

With the description you provided I'd run the cam as designed which is 106 installed center. A general rule of thumb is every 2 degrees you advance the cam you move the peak rpm torque down 200 rpm.
 
Bad Sport said:
OK, so I have another 360 I'm toying with. I have never used the offset keys, but am wondering if/what the advantages are.

I have a Cloyes timing set with no provision to advance or retard timing.

SO, what are the performance advantages.

This will be a stock bore 360 (about 9:1 or a tad better compression), Speed Pro pistons, Comp XE268 cam, LD340 intake, factory J heads with a mild porting just for clean up,--carb undecided--.......
Click to expand...

Low end torque, better if advanced.... Retarded = top end power (that came,not needed ,Bruce... A sweet combination.. The valve job ,is the most important thing here...(unless doing more than a bowl port,or working more than .520" lift)....
 
In my opinion, you pick a cam that's right for what you want from the engine and matching the other components. Then degreeing the cam would be for verifying the cam is in where it should be in relation to the crankshaft, regardless of accuracy of machining on the block, cam, or timing set. Degreeing allows the builder to verify it's in where it's supposed to be. You can advance or retard the cam's intake centerline by adjusting the keyways, but IMO that means you probably have the wrong cam. It's way too general to say "they all run better with a couple degrees advance". They don't. I haven't had to use keyways to "fix" cam timing since I stopped using MP cams. Many of those ones DO want to be run advanced even when you can get them into the recommended ICL. Many also look like they've been ground by a blind monkey having a bad Friday.
The short answer - if you want low end torque - use a cam that closes the intake valve early enough to develop good cylinder pressure at low rpms. Then degree it to make sure the ICL is where it's supposed to be. If you run the right cam, from a decent manufacturer, you won't need keyways unless the timing set or crank were poorly manifactured. And if you buy a decent timing set (Summit billet is one of my favorites for quality, adjustability, and value) then you can use the timing set to correct any issues degreeing finds.
 
Abodybomber said:
The valve job ,is the most important thing here...(unless doing more than a bowl port,or working more than .520" lift)....
Click to expand...

Competition valve job has been done on the heads. I ordered all of my porting stuff today.

I just want to clean things up a bit to help flow.
 
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