Advancing/ Retarding Camshaft

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dustermaniac

dustermaniac

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Just wondering what the benefits or disadvantages are in advancing or retarding Camshaft. I am going to be swapping out the camshaft /lifters and was wondering if this would be beneficial for more lower end. mid range torque. The bushings I am looking at are in degrees of 0,2,4,6,8. Any assistance on this is most helpful. Comp Cam Camshaft, Hydraulic Flat Tappet, Advertised Duration 272/272, Lift .454/.454,
 
That's a great simple deal with Lunati. I'll just add that if you feel you need to move a cam more than 6°, you really bought the wrong cam.
 
I got a 273 that someone before me put a cam in and have low compression(think they
put in the low compression pistions when they rebuilt it) Anyway, couldn't get it to ping
no matter how much I advanced the timing so I took the timing chain off, counted sprockets, figured 1 tooth is about 8 degrees. Advanced the timing by one tooth. The compression is now a little better and it runs better than it did. Verified advance when I put the timing light on it - had to turn timing back about 8 degress. I read somewhere that if you have to advance your timing more than 8 degrees - your cam is too big.
Also read somewhere that if you advance your timing, your basically moving your power
curve also. So if you advance it - if your old power curve started at 4k, it might now be
around 3-3.5k.. In my case, think my cam is too big and I don't want to risk bending valves by advancing any more than 1 tooth.
 
moper said:
That's a great simple deal with Lunati. I'll just add that if you feel you need to move a cam more than 6°, you really bought the wrong cam.
Click to expand...

I would have to 2nt all of that.

Berlins, you advanced it one "tooth".......and it ran.......better!!!! how big of cam is it?
 
The shape of the curve is determined by the cam grind.

Advancing shifts the power band sooner (lower) and retarding shifts it later (higher).

Advancing gives you more off the line, where retarding gives more at the top of the rpm band.
 
Cudafever said:
I would have to 2nt all of that.

Berlins, you advanced it one "tooth".......and it ran.......better!!!! how big of cam is it?
Click to expand...

one tooth is like 15 degree's isn't it?? lol

krazykuda said:
The shape of the curve is determined by the cam grind.

Advancing shifts the power band sooner (lower) and retarding shifts it later (higher).

Advancing gives you more off the line, where retarding gives more at the top of the rpm band.
Click to expand...

bang on kuda!
 
I don't know how big the cam is - someone rebuilt the motor and put some sort of hydraulic cam in there. As for the timing I counted the number of teeth on the big
cam gear and divided it by 360 - came out each tooth was close to 8 degrees. For
some reason thing there were 47 teeth on cam gear(360/47=7.**) I was hoping to see some numbers on the front of the cam when I had it apart but didn't see anything.
 
I've heard it said "if you have to advance your cam timing it's too small / if you have to retard it, it's too large" that said I had a Aussie GM 308 with a mid sized cam set to 6 degrees advance with a blue printed Quadrajet and good headers. Overall top end didn't change that much but mid range was great. A lot of guy's that were into all out top end were shocked by the real world power of this basic engine. Many thought it had 150 + more HP than it did just because of the power it made at 4,500 - 5,000 RPM. An open road trip saw guy's with 400 + HP 327/350 Chev's and 3.55:1 gears complaining I was driving too fast! You just need everything to work well together to make realworld usable power.

Marty
 
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