pushrod length: unusual
pushrod length: unusual I noticed most people go with 7.3~7.4" pushrods with performance cams. I measured mine and to achieve .08~.1" preload I need a 7.525" pushrod. The block was milled .015 and the heads .005. I have Yella Terra rockers that are shimmed .042. The cam is 232/240, .575/.585.
Considering the milling I find it strange that I need such a long pushrod. Could I be doing something wrong? I converted the lifters to solid and made sure the cup was in the same place.
Considering the milling I find it strange that I need such a long pushrod. Could I be doing something wrong? I converted the lifters to solid and made sure the cup was in the same place.
You verified the lifter was sitting on the base circle of the camshaft as well? What tool or method are you using to find that number?
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I converted a lifter into a solid lifter by gutting it and milling a spacer to go inside under the cup.
I made sure the cup was in the same position relative to the lifter body.
I made an adjustable pushrod using an old 5/16 SBC pushrod that I threaded.
I installed everything on the base circle and adjusted the pushrod until I had zero lash.
I pulled the rockers and measured the pushrod. I measured 7.425". If I add 0.080" for preload I get 7.5".
I made sure the cup was in the same position relative to the lifter body.
I made an adjustable pushrod using an old 5/16 SBC pushrod that I threaded.
I installed everything on the base circle and adjusted the pushrod until I had zero lash.
I pulled the rockers and measured the pushrod. I measured 7.425". If I add 0.080" for preload I get 7.5".
Remember, when you order a 7.400" 5/16"pushrod, tip to tip it will measure about 7.417" or so. That's gauge length. So take off the .017-.020" from your tip to tip length, and your zero lash will be right at 7.400" (round to nearest .025" which is the standard length increment). Then add your preload. From your measurement, I'd go 7.475" which will measure tip to tip about 7.495".
What heads are you running?
What heads are you running?
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Remember, when you order a 7.400" 5/16"pushrod, tip to tip it will measure about 7.417" or so. That's gauge length. So take off the .017-.020" from your tip to tip length, and your zero lash will be right at 7.400" (round to nearest .025" which is the standard length increment). Then add your preload. From your measurement, I'd go 7.475" which will measure tip to tip about 7.495".
What heads are you running?
What heads are you running?
Heads = L92 on LS2 block with Manley Race Master valves and PAC1518 springs set at 1.8" seat height. I didn't have to shim the seats which I found strange.
Maybe the valves are longer than stock causing the pushrod to be longer. I know that w/o the Yella Terra shims, the wear pattern on the valve tip is not good. So I had to raise the rocker slightly to get a narrow and centered pattern.
Longer valves = shorter pushrod though.
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POWERBOND - ASP - AND MORE!
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COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
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Nice work serpentnoir.
Matt, thanks for the 0.017-0.020 info. I was wondering why some of my measurements weren't quite adding up and forgot about that
Matt, thanks for the 0.017-0.020 info. I was wondering why some of my measurements weren't quite adding up and forgot about that
