vintage chromoly

iTrader: (3)

Hello all.
Working on an engine project.
512 merlin block
Springs will have 195 closed and 540 open psi.
55 MM Mech roller with .700" lift.
Jesel shaft mount rocker arms.
6000 rpm max.

What size pushrods?
Diameter?
Wall thickness?

I intend to consult bob as he's providing the cam, lifters and springs but just a bit bored and doing some research.

Thanks all,
Rob

mike tkach

iTrader: (3)

i have been useing the 3/8 dia pushrods with .135 wall from trend performance.they have just about any length in stock.i think bob sells a .120 wall pushrod that will be almost the same.let us know what bob sais.

mike tkach

iTrader: (3)

the spring seems a little light for a solid roller.i am running that on my hyd roller 588s.

vintage chromoly

iTrader: (3)

Hey mike. I will post what bob says.

On a side note, the engine had a .720 lift cam and had .842 crower solid lifters and 3/8 .080 walled CV (which I believe are made by trend) pushrods in it. It had the 55MM cam and they spun it to 7500+ rpm.

vintage chromoly

iTrader: (3)

Springs are what Bob specified.

Craney

iTrader: (2)

I got my push rods from Bob and they were Manton push rods.

vintage chromoly

iTrader: (3)

From the research I've been doing, it appears that the diameter affects the deflection and the wall thickness affects the compression of the pushrod.

It's hard for me to imagine a pushrod being compressed but easy to imagine the delection.

mike tkach

iTrader: (3)

it stands to reason that the thicker wall would also help with the deflection.i would love to see a comparison with an .080 wall vs .135 wall on a spintron.

14 apache

iTrader: (1)

I did a set up similar to that 714 lift and 195psi maybe a little lighter at 6000 worked perfect. 3/8 .080 maybe .120 wall pushrods I forgot.

How many people run the valve spring oilers not the rocker arm ones?

This was with std camshaft and .842 lifters

Black Baja

iTrader: (2)

55mm cam and larger lifter wheel doesn't need as much spring. Sorta like a gear reduction/ a lot less pressure angle.