Double check - Mixed opinions on PR length and preload
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TECH Enthusiast
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From: Detroit, MI - Camp Pendleton, CA
Double check - Mixed opinions on PR length and preload I found alot of great info searching on lifter preload and push rods length but am getting some mixed opinions. My setup:
F14-Futral Camshaft - 232"/234" .598"/.598" 112LSA
98 block not decked
-4cc flycut pistons
Stock Ported heads - Milled .025
Stock rockers
.042" graphite gaskets
Gaterman OE lifters (ebay)
I got a pushrod checker and came out with 7.25 zero valve lash. I had the stock 7.4s in and the valves were definately opening with tightening to spec. Obviously the 7.4's are too long. I cant find specs on the lifter preload but I would imagine .060-.100. The most likely canidate would be a 7.35 if I were to add .100 preload. Would I be correct in this setup? Thanks guys -Alex
PS- These lifters are new and feel like they are almost solid lifters. I took a screw driver to see if I could compress an old one and they wouldnt budge, is this normal? It just has me thinking.If I were to add lifter preload, it almost seems as if it would open the valve instead of compressing the lifter.
F14-Futral Camshaft - 232"/234" .598"/.598" 112LSA
98 block not decked
-4cc flycut pistons
Stock Ported heads - Milled .025
Stock rockers
.042" graphite gaskets
Gaterman OE lifters (ebay)
I got a pushrod checker and came out with 7.25 zero valve lash. I had the stock 7.4s in and the valves were definately opening with tightening to spec. Obviously the 7.4's are too long. I cant find specs on the lifter preload but I would imagine .060-.100. The most likely canidate would be a 7.35 if I were to add .100 preload. Would I be correct in this setup? Thanks guys -Alex
PS- These lifters are new and feel like they are almost solid lifters. I took a screw driver to see if I could compress an old one and they wouldnt budge, is this normal? It just has me thinking.If I were to add lifter preload, it almost seems as if it would open the valve instead of compressing the lifter.
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
If your measurement was correct 7.325 Comp cam would be the likely candidate.
BUT, first contact the lifter manufacturer and ask what is the recommended preload range, then base your decision on that.
BUT, first contact the lifter manufacturer and ask what is the recommended preload range, then base your decision on that.
