SBC piston pins

I'm, standing here at the press,push the pins out at room temperature? Same for pressing in new pins? Thanks

 

No. Pushing in the new pins if they are press fit needs the pin end of the rod expanded by heat. This is best accomplished with a special devive found in automotive machine shops.

 

i press them apart using a fixture i made to support the piston so i don't mess anything up...even though i probably won't be re-using the pistons. i use heat on the small end of the rod and the pins cool to slip them together. you have to work fast , you only have seconds! the heat from a propane torch is enough

the book "how to rebuild a SBC" by david Vizard has a good description on how to do this

 

Most machine shops use a small "oven" with a temp gauge to heat the small end of the rod to expand it to drop the pin in. If it's done right the color of the rod doesn't change much, maybe has a straw color to it. If you heat them more than they are needed they turn blue or ???. Might be ok, might not.
Larry T

 

Straw color is about 400 degrees I think.

 

Put the pins in the freezer, warm the rods in the oven, I use a toaster oven in the
garage. There is a special lube for the pins to keep them from galling the pistons and rods, high temp stuff.

 

On installation you need a special fixture to install the pins in as you have to end up with the rod on the center of the pin when pin is in center of piston.The jig bolts to the bench when you use the correct tooling as you only get one chance.Get a shop to change over and align the rods rod orientation is critical 4 l/h 4 r/h.Think this through before you tackle it.Shops use a rod oven to heat rods and pins are at room temp.The rods have to be aligned after pin installation.The pins don't require a press fit when rods are hot. My2¢
Hope this helps

Tig.