piston ring expander/compressor

[rjcthree]

Engine builders - what / how did you fit your piston rings to pistons and pistons to cylinders?

The 5 1/8" piston ring compressor is somewhat hard to find!

Rick - days from building.

[Radomir]

Here's an example:

http://www.skygeek.com/ats-7500.html

This is the whole set.. you can just buy one ring and those "pliers" and that'll do..

[Vern]

The circular band type works OK for one engine. It would be a drag if you used them everyday. Available for approx $15-20 online. Size is used on tractors/big trucks.

[robpar]

The tool shown in the link is a very good ring compressor, a bit pricey if you are only going to do this once. Rent, Beg, Borrow?

I built a lot of engine while an auto mechanic and I have used the cheap coil band type, which work but you have to be careful and there is an up and down to them. Even being careful those pesky rings can get out. If you have not used those coil ring compressors and can not borrow one of the good ones than considering the cost of a cylinder should a ring scratch the bore it might still be cheap.

Bob Parry

[Lionclaw]

Rick, did your pistons come separate from your cylinders? Is it generally considered a good idea to take them out to inspect, or do most people just put in the pin and bolt the jug on?

[rjcthree]

I ordered a simple band-type compressor and a pliers-type expander. Should be fine.

Andy: Pistons, rings, cylinder are all separate. Cyls are painted, base to head, Lyc grey. Oddly, they did not come with rocker covers - the parts manual is wrong on that one, but they came with a whole bunch of orings (and I'm trying to figure out the logic of which ones) and two kinds of wristpin buttons.

I will be measuring everything pertinent, directly or indirectly. For instance, if the bore is right, the ring gap should be too, at specified positions.

Nothing mysterious in the boxes or about the parts. Bunch of $$$ though. Just doing my part to keep the economy going before somebody figures out how to take it from me.

Rick 90432

[Lionclaw]

Darn, I was hoping all the work would be done for me.

I read in Lycoming's FAQ on cylinder kits that the assembly arrives "loaded". I interpreted that to mean it was all assembled and ready to be installed.


http://www.lycoming.textron.com/supp.../Key%20FAQ.pdf

[rjcthree]

Loaded with valves, springs, seats, keepers, studs . . . but not pistons.

The oil drainback fitting is installed, btw.

Pushrod shroud seals included- both T mod and not. Cyl base oring not. Three orings I don't recognize - and I have the Lyc seal kit - are also included. Weird. And for the life of me, I cannot find a partslist of cyl kit or seal kit that is ACCURATE. For instance, the cyl kit in the parts breakdown would have you believe rockers are included - I pointed this out in black and white to the Lycoming folks at OSH this year, they agreed, but just shrugged it off. Getting from the parts supercession manual is not possible - as the parts count doesn't match. Oh, and the mag drive cushions aren't included anywhere.

I have some confidence all the stuff is there, but come this weekend, we will find out. I'm going to at least build the block this weekend.

Rick

[az_gila]

Originally Posted by rjcthree

...

Oh, and the mag drive cushions aren't included anywhere.

I have some confidence all the stuff is there, but come this weekend, we will find out. I'm going to at least build the block this weekend.

Rick

...that in the "A" series, only O-360-A4A and -A4J models use magneto drive cushions.

Which model will yours be equivalent to?

[rjcthree]

Mag drive cushions for the Bendix D3000 on a O-320-H2AD - LW-12136 x 2 - may not be the current number, I don't have supercession manual with me at work . It also takes a retainer, 68875.

By 'didn't come with anything' I meant that they were not part of the seal kit nor part of the hardware kit that came with the overhauled mag, which seems like a miss. New zip ties came with the kit, but not drive cushions?

Rick