"Lapping" the Piston and sleeve?

[dwilfong]

I use Brownell's garnet lapping compound 1000 grit mixed with a little WD40 to make a paste.It takes some time to do it but you can see on the piston and in the sleeve where it mates.

When used with the liner squeezer you can make a very good seal.

You must reassemble the eng to check seal because it will change when you tighten down the head.

David:

The fit shouldn't change when you tighten the head if the button/liner fit is correct and the liner/case fit is correct. I spend a little time lapping the top flange of the liner to the case to help with this.

The compound that you use is the same that I have used for 20 years and is the best that I have found also.

Marty

I have noticed that when using the liner squeezer that the fit changes when you tighten the head.

The fit sames to loosen up so I always reassemble the eng and check the fit before I lap.

I think this is due to the way the liner pinches the sleeve. I have also noticed that if I true up the top of the sleeve before I assemble it is not as bad.

I never thought about lapping the liner to the case and button to liner.

Yes the button dose get tight after pinching sleeve.

Thanks for the tip.

David

Not to BUTT in here but...... Think about what pinching does..is the liner really round after that?

Not if you don't do it to much in one spot

If you do it a small amount at a time and rotate the sleeve it pretty round. You cant pinch it all at once and in one spot.

You get the feel for it. It kinda like tightening a bolt after may years of turning a wrench you know how tight tight is.

I always tell new mechanics, YOU DON'T HAVE TO KILL IT, IT'S ALL READY DEAD!!!!

 

[mark voorhies]

I use Brownell's garnet lapping compound 1000 grit mixed with a little WD40 to make a paste.It takes some time to do it but you can see on the piston and in the sleeve where it mates.

When used with the liner squeezer you can make a very good seal.

You must reassemble the eng to check seal because it will change when you tighten down the head.

David:

The fit shouldn't change when you tighten the head if the button/liner fit is correct and the liner/case fit is correct. I spend a little time lapping the top flange of the liner to the case to help with this.

The compound that you use is the same that I have used for 20 years and is the best that I have found also.

Marty

I have noticed that when using the liner squeezer that the fit changes when you tighten the head.

The fit sames to loosen up so I always reassemble the eng and check the fit before I lap.

I think this is due to the way the liner pinches the sleeve. I have also noticed that if I true up the top of the sleeve before I assemble it is not as bad.

I never thought about lapping the liner to the case and button to liner.

Yes the button dose get tight after pinching sleeve.

Thanks for the tip.

David

Not to BUTT in here but...... Think about what pinching does..is the liner really round after that?

Norm,

You tell me, within hundred thou., yes, within ten thou.? how much tolerance do we need?

It does make a worn out P/L work again, with a good fit.

 

[Norm Doerr]

I use Brownell's garnet lapping compound 1000 grit mixed with a little WD40 to make a paste.It takes some time to do it but you can see on the piston and in the sleeve where it mates.

When used with the liner squeezer you can make a very good seal.

You must reassemble the eng to check seal because it will change when you tighten down the head.

David:

The fit shouldn't change when you tighten the head if the button/liner fit is correct and the liner/case fit is correct. I spend a little time lapping the top flange of the liner to the case to help with this.

The compound that you use is the same that I have used for 20 years and is the best that I have found also.

Marty

I have noticed that when using the liner squeezer that the fit changes when you tighten the head.

The fit sames to loosen up so I always reassemble the eng and check the fit before I lap.

I think this is due to the way the liner pinches the sleeve. I have also noticed that if I true up the top of the sleeve before I assemble it is not as bad.

I never thought about lapping the liner to the case and button to liner.

Yes the button dose get tight after pinching sleeve.

Thanks for the tip.

David

Not to BUTT in here but...... Think about what pinching does..is the liner really round after that?

Norm,

You tell me, within hundred thou., yes, within ten thou.? how much tolerance do we need?

It does make a worn out P/L work again, with a good fit.

You mean less than a thou? a hundreth of a thou I assume? I will give it a shot and see what happens. I have seen some folks do it in the past with "not so good" results. Could be they may have not done it correctly so I abandoned the idea and went a different route.

 

[Chris Wood]

that is because they don't TAKE THERE TIME.. as is with most stuff.

chris

 

[Norm Doerr]

that is because they don't TAKE THERE TIME.. as is with most stuff.
chris

Bingo!!!! and don't want to learn!

 

[Chris Wood]

you got it norm, want to buy it all READY TO GO lol.

truth be told they work great.. it is like anything else.. they are a TOOL.. not a end all be all

chris

 

[Norm Doerr]

you got it norm, want to buy it all READY TO GO lol.
truth be told they work great.. it is like anything else.. they are a TOOL.. not a end all be all

chris

I have one in the shop