[butchfig8]

grew up with john Deere 2 cyl, 1950's, learned to weld at 7, south east asia at 19, eng uw madison, race fig 8, build wrecks, looking for fishing partners.
Looking for answers about 350 chevy pistons.
Have new pistons, what is the secret for pressing wrist pins & piston onto rods,
a couple i have done seam tight

[cobalt327]

Originally Posted by butchfig8

what is the secret for pressing wrist pins & piston onto rods,
a couple i have done seam tight

My machine shop uses heat to expand the pin end of the rod so the pin fits relatively easily into position. This has to be done in a deliberate fashion- if you don't get the pin positioned correctly, you have to press it back out and start over.

If you're doing it cold , you need to have the correct fixtures to avoid damaging the piston or pin/rod assembly. Frankly, I wouldn't advise this.

[eloc431962]

Welcome to the site.


Cole

[zildjian4life218]

I have pressed a few in myself with a 6 ton press. They were only 305 pistons so no big deal if i messed up. A few were tight afterwards but my machinist said as long as you can move them by hand it will be ok. Like stated above I wouldn't advise doing it yourself. I always run float pins if i have the choice.

Machine shops have a special fixture to hold the rod and piston so all the force is exerted on the rod and not the piston. The idea is the pin spins freely in the piston pin bores but is tight on the small end of the rod. So when you press the pin into the rod you want to be pressing against the rod not the side of the piston(if that makes any sense).

If they are stock cast pistons with stock rods that will be in a low rpm beater sure whatever try it, but anything mildly performance oriented spend the extra money to have the machinist do it. They will know what feels like a good fit or if its taking too much force.

Like cobalt said some places heat up the small end of the rod so it expands then it can be easily slid into position.