Push Rod Length: Shorter vs Longer

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Walter R. Malik
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Re: Push Rod Length: Shorter vs Longer

Post by Walter R. Malik »

skinny z wrote: Sat Nov 27, 2021 8:32 pm When your calculated push rod length falls between two standard measurements, do you go longer or shorter?
Say I find 7.385" is ideal. So is it 7.375 or 7.40" ?
This is a hydraulic roller with .575" lift via 1.6 rockers.
Whichever would allow the better geometry on the pushrod side.
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Re: Push Rod Length: Shorter vs Longer

Post by skinny z »

Walter R. Malik wrote: Mon Nov 29, 2021 8:32 pm
skinny z wrote: Sat Nov 27, 2021 8:32 pm When your calculated push rod length falls between two standard measurements, do you go longer or shorter?
Say I find 7.385" is ideal. So is it 7.375 or 7.40" ?
This is a hydraulic roller with .575" lift via 1.6 rockers.
Whichever would allow the better geometry on the pushrod side.
I'll look into this should this same scenario come up with my own project.
This was for a poster on another forum and I think that deal is sealed. But eventually, I'll be working on my own pile of parts. Again.
Kevin
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Re: Push Rod Length: Shorter vs Longer

Post by steve cowan »

I was recently reading where Larry tested on dyno and track
More hp with Sweep pattern on pushrod side but potentially more guide wear.
Obviously application specific,
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Re: Push Rod Length: Shorter vs Longer

Post by skinny z »

steve cowan wrote: Tue Nov 30, 2021 3:21 pm
More hp with Sweep pattern on pushrod side but potentially more guide wear.
Guide wear is precisely the issue.
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Re: Push Rod Length: Shorter vs Longer

Post by steve cowan »

Personally I get pushrod length with heavy spring I am using, I find big difference in checking spring and heavy roller spring
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Re: Push Rod Length: Shorter vs Longer

Post by skinny z »

steve cowan wrote: Tue Nov 30, 2021 3:29 pm Personally I get pushrod length with heavy spring I am using, I find big difference in checking spring and heavy roller spring
Same here.
Even 140 lbs on the seat makes a difference.
Kevin
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