Who runs 7.425" pushrods?
#1
Who runs 7.425" pushrods?
I heard that to quiet down your valvetrain you can run a 7.425 pushrod. This ofcourse is if your cam isn't humongous. This probably applies to the .570-.590ish lift cams out there I would assume. Anyone see any results from running the longer pushrod as opposed to the 7.4?
#2
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It has nothing to do with cam size, its about accomplishing the correct preload. Since the stock rockers are non adjustable preload has to be set by either shimming the rockers (pain in the ***) or getting the right pr length (need to invest in a length checker) If your worried about it and want to get it right invest in calipers and a measuring pr that way you can get pretty close to the correct plunger depth.
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Cam size means nothing. It is the base circle of the cam that determines the preload. I run them because I wanted more thanthe .040 preload that most people end up with when they use 7.4's. I measured mine with a PR length checker and the 7.425 gave me .065 preload.
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aus1320 (02-11-2023), Homer_Simpson (03-18-2023)
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I just fired my car up tonight after installing a set of patriot ls6 heads and their 226/226-585/585 cam along with 7.425 pushrods and HS rockers and the valve train is VERY quiet! I used the comp cams adjustable pushrod to measure the lifter preload and I also checked the swipe pattern of a few different length pushrods and the 7.425's were right on the money!
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#9
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If running fixed fulcrum rockers (stock, Yella Terra, Harland Sharp) pushrod length will not affect your wipe pattern, only the lifter preload. If you want to figure out the correct preload, buy a $20 adjustable pushrod and take the measurements. Its the best and most accurate way to do this. Make sure your wipe pattern is correct first, then measure for pushrod length.
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Originally Posted by greatwhitess
Cam size means nothing. It is the base circle of the cam that determines the preload. I run them because I wanted more thanthe .040 preload that most people end up with when they use 7.4's. I measured mine with a PR length checker and the 7.425 gave me .065 preload.
Werd. That's why I run 7.45's.
#11
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Originally Posted by quiet_storm98
so what about if your heads are milled?? does that make a difference in what pushrod length you should use?? for instance i have some tea 5.3 heads that are milled 0.15 so i am wondering what length of pushrod i need.
#13
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Stock lifters have up to .100 preload on stock cams so no issues.
With a TR230 7.425 is the way to go.
XE/XE-R and in between (TR lobes) like the extra .025 on cam only.
With a TR230 7.425 is the way to go.
XE/XE-R and in between (TR lobes) like the extra .025 on cam only.
#17
Cam size means nothing. It is the base circle of the cam that determines the preload. I run them because I wanted more thanthe .040 preload that most people end up with when they use 7.4's. I measured mine with a PR length checker and the 7.425 gave me .065 preload.
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G Atsma (02-11-2023)
#19
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How times have changed!
I still remember WAAAY back in the day, on a SBC you backed off the rocker arm nut until it clicked, then went down just a quarter turn.
Pump-up alleviated. NOT prevented, just put off a few more RPM.....
I still remember WAAAY back in the day, on a SBC you backed off the rocker arm nut until it clicked, then went down just a quarter turn.
Pump-up alleviated. NOT prevented, just put off a few more RPM.....