Getting Pistons into the Barrel without breaking the Rings

Steverinomeiste · Post by **Steverinomeiste** » Sat Jul 05, 2014 3:39 pm

Hi Everyone:
I'm not having any luck finding a thread, I know it's out there, on compressing the rings and slipping the pistons into the barrel without damaging them.
Thank You for your help.
Steve

Spokes · Post by **Spokes** » Sat Jul 05, 2014 7:50 pm

I hope I'm not the only member to chime in. Please remember I'm a rogue technician at times.

I oil the cylinder with motor oil, any clean oil works. I carefully lower the jugs to the 1st ring. I compress the top ring with my fingers on one side until the ring slips in. I move to the opposite piston and repeat.

I do the same technique back & forth until the pistons slide into the cylinders.

Do not force any ring. Use light pressure on the cylinder if need be.

I have done this technique on seven engines. I did ruin one ring by forcing the cylinder down. So my technique is not with out risk.

Steverinomeiste · Post by **Steverinomeiste** » Sat Jul 05, 2014 11:23 pm

Thank You Chip
I followed your instructions and all went smoothly. Thank You.

ByTheLake · Post by **ByTheLake** » Sun Jul 06, 2014 4:17 am

Chip isn't a rogue in this case. For small bikes like our Benly, I've found it easier to install the pistons through the top, one at a time, with their inboard wrist pin clips already installed. I then lower the cylinder over the studs with the pistons protruding from the bottom just enough to slide the wrist pins through the piston and connecting rod. Then the outboard clips are installed and the cylinder is lowered the rest of the way.

I swear that I learned this from something Sam wrote, but he says that he's not guilty of this malpractice.

Spokes · Post by **Spokes** » Sun Jul 06, 2014 5:12 am

Installing the pistons in the cylinder from the top and then connecting the rods from the bottom sounds interesting.

I have two engines in the process of being rebuilt. I'm going to try the technique for kicks & grins.

Thanks Kevin.

ByTheLake · Post by **ByTheLake** » Sun Jul 06, 2014 5:59 am

Spokes wrote:Installing the pistons in the cylinder from the top and then connecting the rods from the bottom sounds interesting.

I have two engines in the process of being rebuilt. I'm going to try the technique for kicks & grins.

As long as you don't forget to install the inboard wrist pin clips in the pistons, it's easy. I have one small piston ring compressor, so this method allowed me to use the ring compressor and tap the pistons into the cylinders one at a time.

Nige1100s · Post by **Nige1100s** » Tue Jul 08, 2014 9:19 am

I have used zip ties as ring compressors but last time I put the pistons in the barrels (jugs if you must) from the bottom and pulled the gudgeon pins in using a length oft stud.

Steverinomeiste · Post by **Steverinomeiste** » Sun Jul 13, 2014 8:26 pm

Thank You for your help. I've got the Barrel Seated and I am now assembling the head which should prove to be very interesting experience.