[LeMans70Sport]

I was wondering if that can be done at home with a newly purchased 12 ton press or is it better left for a machinist? I don't want to break a piston or rod of course so I was wondering what kind of clearances I should be looking for.

Thanks,
Steve

[Jack Gifford]

Just my opinion- "Don't try this at home!"

[Ken K]

You don't want to use a press. It's better to use a rod furnace. They go right in that way. If you get one that did not go in all the way and end up using a press, you can feel it binding up, it will loosen up after the engine is run. If you use a rod furnace, the pistons move freely. The factory heated them up, you can see the discoloration on the small end of the rod.

[PONTIAC DUDE]

Never Press piston pins on.

Some pistons are not level to the outside flat inside the piston and can offset the pin on insertion causing bind issues. Piston distortion in the pin area, along with possible cracking that might not be detected can occur.
Any binding of the rod in the piston can also cause rod bearing failure.

I make money all the time from people trying to press on thier own pistons and then end up having them come, order another piston or pistons and heat them on.

Also be careful pressing them off. Make sure the rod isn't in a bind in relation to the piston. I have seen bent rods from removing them improperly.

[LeMans70Sport]

I'll have them presses on at the machine shop. Good information. Thanks for the replies.

[flamedabone]

Just my .02..

I try to do EVERY possible thing myself, from alignments to headers. I even build my own thermostat housings...but I leave pressing pistons to my machinist. He charges 2 dollars each and uses a Sunnex rod oven that looks like it came from the 1930s..

You will hardly even notice 16 bucks tacked on to your machine shop bill.

-Abone.

[Tom Vaught]

The Ford Motor Company can buy the best equipment and they have a small rod furnace at the Research Engine Build-Up Lab. They heat the rod SLIGHTLY and chill the pins in liquid Nitrogen. Works like a champ. USE GOOD GLOVES when installing the parts.

Tom V.

[b-man]

I used to do my own at work. A large arbor press, a torch to carefully heat the rod and a dewar of liquid nitrogen to shrink the pin. A few drops of oil helps too.

I had a tool made out of aluminum round stock that was about .020" smaller in diameter than the piston pin and about 5" long, with a 1/2" long pilot feature that fit inside the pin on one end.

I supported the piston on a couple of aluminum blocks right next to the pin, the piston has flat areas right there. As long as you watch what you're doing it's pretty easy, the arbor press has a long handle and you can 'feel' the pin go in as it's being pressed, unlike using a hydraulic press. Never hurt one.

I used to build industrial machinery, we had plenty of tools and a full machine shop and weld shop on site.