0.500" Lift With An Austentemper Cam & PAC 1201's

T

TTipe

Snake Skinner
Joined
Jul 25, 2008
The data which I received from the cam supplier does not support 450 lbs of spring pressure on an austentemper cam. Then I have folks who have been around these cars for years telling me this combination will live without incident based on the integrity of the cam. I set my car up based on a 500lb spring load capacity (and a safety factor hopefully) with an austentemper cam and I'm ready to go billet (sucks). I'm not looking forward to tearing into my new engine to change cams. Is anyone doing this successfully because if so the supplier data has be to wrong? Any advice is good. Thanks
 
I am using the same set up no Billet Cam and have no ill effects yet , My has about 450 lbs on the nose of the cam with 1201 PAC`s
 
I don't know what your installed height is but mine at 1.775 with PAC 1201's is right at 410 on the nose with a 505 lift austemper cam.
 
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m233roller said:
I don't know what your installed height is but mine at 1.775 with PAC 1201's is right at 410 on the nose with a 505 lift austemper cam.
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The supplier (guess who) told me that with austentemper they want to keep spring pressure under 500lbs as a general rule. However I made a second call and the "technical expert" gave me 455 lbs on the nose and they weren't sure that this was continuous cycling value. Who knows what their target value range is? My new GN1 heads came with Kmotion 750 springs which could have wiped out my engine just the way I think they messed up my friend's engine. I was fortunate that I have not run mine yet.
 
TurboTdr3.8 said:
Going on 2 years
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I'm checking out a solution that reduces spring pressure (down to 370 psi) with no lifter bounce (bumble bee). I was told Kmotion 750 is too brittle. They just work harden and fail! Pac 1201x is better (more ductile) and you can see it going into failure. Obviously it puts more load on the cam. 370 psi on an austentemper cam and no lifter bounce could be a wonderful opportunity.
 
Comp 941 and non to moderate aggressive lobes has worked for years. I've been over .530" lift and no problems under 6000rpm. Actually have the same 941's on one engine I had first used 10 years ago. Been on at least 3 different engines. The slowest of them trapped 126mph in the quarter with a loose converter .


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This got me thinking:

Is the quality of the springs we're getting today the same quality we got from the same manufacturers a few years ago?
K Motion used to be an excellent spring,but now I hear they have problems?

BTW,it sounds like TTipe was talking to Mike Jones at Jones Cam Designs.
 
The Radius Kid said:
This got me thinking:

Is the quality of the springs we're getting today the same quality we got from the same manufacturers a few years ago?
K Motion used to be an excellent spring,but now I hear they have problems?

BTW,it sounds like TTipe was talking to Mike Jones at Jones Cam Designs.
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I don't remember K Motion ever being a quality spring. I think if anything they remained the same and the quality of the rest of the valve train parts has gotten better.
AG.
 
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