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How many runs on your PAC valve springs

Endangered Species

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How many passes are you getting out of your PAC valve Springs?

I have pac-1347 triple springs with 80 passes on them running a 800-785 cam. Was thinking about going with a smaller cam 733-700 and was contemplating running these springs if they all check out okay.

Thanks
 
I run the unpolished 1225 springs. Cam is 285/292,.800". I swapped them at 200 passes. We checked them against the new set . We have a pretty sophisticated checker. The old ones were 100% as good as the new set. This time I'm going 300 passes between removing them. The on the car checker shows good.
Doug
 
Thanks Doug! That's what I was thinking but I wanted to here from some experienced racers.
I had bought a new cam last year from Crane, it's 800-815 and Rob from Crane wanted 350 on the seat and 840 open for springs, so that means I would have to buy new springs.
I think I'm going to shelf the cam and buy the smaller one... then run the springs I have.
(my funds are running a little tight)

Thanks again brother
 
Thanks Doug! That's what I was thinking but I wanted to here from some experienced racers.
I had bought a new cam last year from Crane, it's 800-815 and Rob from Crane wanted 350 on the seat and 840 open for springs, so that means I would have to buy new springs.
I think I'm going to shelf the cam and buy the smaller one... then run the springs I have.
(my funds are running a little tight)

Thanks again brother
 
Plenty of room to shim that spring .070" safely. The spring rate for 1347 is .685#/". So every .010" you tighten them up gains you 6.85#/" .050"shim should easily fit at. 820". Plus you have lash. That would give you around .090" running to coil bind .
258/903 pressure at 2.020" installed. I run mine at .065" running clearance to bind including lash
Doug
 
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Great point! You got me thinking... I will play around with shims and see what numbers I'm getting. I may be able to get away with what I have.
I was just thinking if I went with the 700 lift cam that has a duration only 2 degrees less than the 800 it would be easier on the springs and valves?
I was going to reuse the entire cylinder head assembly on this motor. So the valves and locks have about 50 passes on them and the springs have 80 passes... not sure on the Ti retainers

If my budget hadn't taken a hit, the plan was going to just replace it all... However if I want a prayer of getting out this year I need to shed some cost. Unfortunately the valve train isn't some place to cut cost. ESPECIALLY on a Hemi. LOL

Thanks again for all your help!
 
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