Correct push rod length question....

[isaiah3g]

So I have 2 motors with similar builds...

32/28 valves ported, 310 cam, billet flywheel, 40 though longer rod,flat top piston, billet lifters, hl380 tilly on alchohol, 1.3 roller rockers.

Here's the question,
One motor started as hemi, the other non.

Would the hemi block one need 5.440 (hemi length) push rods or are the 5.200 ones better to use?

Just looking for the better setup. I've heard that the pushrods stay with the block no matter the head swap.

Someone hep meh!

 

[OND]

isaiah, with the valve half way open the rocker arm needs to be in the center of the valve stem or lash cap....does that make sense ?

 

[isaiah3g]

Absolutely makes sense.

So I will check the positioning on them and check back later on!

Have....eh....3 motors to build for minibike mania in april.

 

[ole4]

Whose billet lifters are you using? Isky's billet lifters are .180 longer than stock so pushrods need to be shorter, however other mods can alter length as well. Was head milled? Base circle of cam could be smaller than stock, both would change length requirements. On a build where a lot is changed sometimes it is easiest to either make some pushrods from pieces of mild steel rod and use some checking springs or some springs from a hardware store that will fit the retainer but are easy to compress. you could start with stock pushrods and check where the rocker wipes the tip of the valve to see if your length is OK or too long/short. Once you figure out the correct length you can buy the long build it yourself pushrods from ISKY. The old raceseng rockers had shims to fine tune rocker geometry don't know which kind you have.