Piston Challenge

OldStan · Post by **OldStan** » Wed Nov 04, 2015 2:10 pm

I'm stripping down a spare CL77 engine I bought a while back. I've split the case and most of the inside is in good shape, but removing these pistons is going to be a challenge. I don't think soaking it in anything will help! Obviously I'm not worried about saving the pistons. I wonder if drilling in a ring around just inside wall will make it possible to break? Anyone tried that? I'd like to save the crank and case if possible.

G-Man · Post by **G-Man** » Wed Nov 04, 2015 3:17 pm

OldStan

My 2 cents. Take a Dremel cutting disk just below he flange of the liner. Cut both flanges off. Heat the barrel up and slide the barrel off the liners.

Cut the liners off the pistons with a pair of vertical cuts.

Minimal force but scrap liners and pistons.

G

OldStan · Post by **OldStan** » Wed Nov 04, 2015 4:12 pm

Good thought, although I've tried to remove a barrel with the heat of my little propane torch and it just wasn't enough.

I decided to mess around with it and pulled out my air chisel. One piston the impact loosened it enough that it would come out. The other one (first photo) it broke the top out of the piston, then I chipped away until clear down one side of the piston and it came loose. That piston the pin is frozen in the rod, so once I get the rest of the piston off the pin (one side the piston is gone) I'll soak it and see if I can get it freed up.

G-Man · Post by **G-Man** » Thu Nov 05, 2015 1:04 am

Oldstan

Sounds like you have some useful kit in the form of the air chisel.

For heating things up, I have some fire bricks and insulating blanket. It makes a big difference for heat loss.

Good luck!

G

LOUD MOUSE · Post by **LOUD MOUSE** » Thu Nov 05, 2015 5:49 am

I'd say you did a good job with the tools you have.
The several I've had I used a 3/8" drill on front and rear of the piston then used my air hammer.
The pin I usually like you soak it then hold the rod in my vise then using a brass hammer I knock the pin out of the rod.
At present I'm at about 50/50 on finding a usable rod after this. .....................lm

OldStan wrote:Good thought, although I've tried to remove a barrel with the heat of my little propane torch and it just wasn't enough.

I decided to mess around with it and pulled out my air chisel. One piston the impact loosened it enough that it would come out. The other one (first photo) it broke the top out of the piston, then I chipped away until clear down one side of the piston and it came loose. That piston the pin is frozen in the rod, so once I get the rest of the piston off the pin (one side the piston is gone) I'll soak it and see if I can get it freed up.

OldStan · Post by **OldStan** » Thu Nov 05, 2015 10:22 pm

Soaked the pin overnight in Evaporust and was able to turn it. Used WD40 and it turned easily. I cut the piston in half. The hole for pin was half gone on one side so it fell off, cleaned up that end of the pin and it slid right out of the rod. Bore of the rods are good, I've been lucky so far, three engines with seized pistons (this was the worst one), all rods in good shape.

G-Man · Post by **G-Man** » Fri Nov 06, 2015 3:25 am

OldStan

A good result. Did the bottom end stay free from water?

G

OldStan wrote:Soaked the pin overnight in Evaporust and was able to turn it. Used WD40 and it turned easily. I cut the piston in half. The hole for pin was half gone on one side so it fell off, cleaned up that end of the pin and it slid right out of the rod. Bore of the rods are good, I've been lucky so far, three engines with seized pistons (this was the worst one), all rods in good shape.