GS 1000 - Piston Sleeve sticking up to high?

[odl777]

Hello All,
I have a 1978 gs 1000E; it has approximately 50K on the clock. So I decided to overbore to 1100 (Ebay cuznimage). I had a friend bore the cylinders and they look really good! However we both noticed the sleeve on #4 is sticking up slightly higher from the cylinder surface than the rest of the sleeves, enough so that I can get a good grab with my finger nail.

What should I do? The sleeve is no longer loose enough that it will slide down easily...my friend said he really clamped it down when boring. Maybe what he was missing was a lil heat? Could a machine shop get this back in line for me? The cylinder has already been bored.

Thank you!

Mark

 

[Steve]

The engine-building crew will chime in shortly, but I would guess that placing the block upside-down in an oven and warming it up so the block will slide down over the sleeve would work. What I don't know is what temperature it would take to do that.

.

 

[JamesWhut?]

I hope your friend didn't make the liner out of round when he "really clamped it down"...

Steve's idea is the easiest, cheapest fix. 200~300 degrees should be good enough. To be honest though, the compression of the cylinder studs when all assembled squeezes everything back in line (which is why engines can get away with lose cylinder walls). Esp. after torquing after that first heat cycle sorts everything out.

 

[Nessism]

Your friend boring the cylinder most likely used too much pressure on the boring bar and/or hone and the cylinder heated up and now has slid up. The liner will go back down easily using a press. The heating thing as mentioned by Steve may work, but another liner may pop up during the process. You could try heating then removing the cylinder and tapping the offending liner down with a wood block or similar. Supporting the cylinder on a couple 2x4's might help during this process.

BTW, those cruiseimage big bore kits are remarkably cheap. Looking forward to your review.

 

[Steve]

The heating thing as mentioned by Steve may work, but another liner may pop up during the process.

Which is why I suggested turning the whole assembly upside-down.

When heated, the block will expand and drop over any liners that are not flush with its top (now on the bottom) surface.

Allow it to cool before turning it over, of course.

.

 

[odl777]

WOW! thank you everyone!!! Great information and such a quick response!!!! I am going to ask a friend if he still has his press otherwise its to the oven with these bad boys.

When I took the cylinders I noticed number 4 sleeve was slightly protruding. I was hoping that when he bored them it would slide back down the cm or so its is sticking up. Unfortunately this did not occur.

Is it possible that it could have got some dirt in between the sleeve and the block...which is keeping it form easily sliding back down?

Thank you all!!!!

Mark

 

[JamesWhut?]

not likely. Mostly it slid up when being cut or even might have been like that from the factory if it managed to seal and passed QC.

 

[Steve]

I noticed number 4 sleeve was slightly protruding. I was hoping that when he bored them it would slide back down the cm or so its is sticking up.

Quick question: Which one of the bolded statements is true? :-k

I would not call a centimeter of protrusion "slight".

In fact, I think that most engine builders would not allow a millimeter, let alone a centimeter to stick out.

.

 

[odl777]

I havent actually measured it..but I can get a pretty good bite on it when scraping my fingernail across the surface. so maybe more like a Millimeter so. I can tell you it is visible when just looking at it. Ill try to get a pic

 

[Steve]

A centimeter is almost half an inch.

.

 

[JamesWhut?]

Metric system fail.

 

[Steve]

Metric system fail.

No, metric system comprehension fail.

.

 

[odl777]

Good point! I'm not sure what I was thinking when I wrote that. I guess I wasn't haha.

 

[chuck hahn]

They will normally stick up 2 or 3 thousands. heating the steel sleeve during boring wont normally extract it unless the hone hooked up and it was jerked up.

To be sure they are seated tightly to the shoulder in the jugs, I would remove them and clean the seats and the under sides of the sleeves shoulder. To do this, place the jugs in the oven at 350 sitting on the head side. Periodically reach in with a rag and grip the bottoms and see if they will move. once they move, remove the jugs and take out the sleeves. let them air cool..DO NOT hit them with water etc ect.

Once they are cooled you can handle the parts to clean well.

Reassembly.. Stick the sleeves in the fridge for about an hr before you prep the jugs. this will CONTRACT the steel. Next, place the jugs back in the oven at 350 for the same amount of time it took for the sleeves to get loosened. This will EXPAND the aluminum. Place the jugs up on some 4X4s ( or whatever will allow the sleeves to dangle freely from the bottom ) and seat them. Next, place something very flat across the top of the sleeves to hold them down and let it all cool.

The whole process is nothing more than a expansion Versus contraction fitting together thing.

 

[odl777]

Thank you Chuck! Nice write up! I am gonna try this tomorrow when the wife is at work

 

[JamesWhut?]

Try Steve's technique first. Don't "overfix".

 

[chuck hahn]

James..crud will gather between the sleeves and the jugs, so its not an "over fix" to disassemble and be sure its absolutely correct. The only thing that basically holds them in when the engine is hot is the fact the head is bolted on holding them in place.

 

[JamesWhut?]

You're asking a novice to execute a fairly complex, precision fit operation. What is simple for you isn't for others. He's as likely to break something else as fix the original problem.

 

[Nessism]

I wouldn't disassemble the sleeve unless pushing it back down doesn't work. There is almost no way for crud to get between the sleeve and the cylinder anyway unless the sleeve is completely removed.

First choice on the repair technique is to press the sleeve back down cold. If a press isn't available, I'd heat the cylinder gently, and tap the liner back down using a piece of wood. Last resort is remove the liner and clean.

 

[chuck hahn]

Or the oring at the bottom has failed...then all sorts of crud DOES migrate around the outer edges of the sleeves Ed. Ive taken what otherwise looked like perfectly clean head tops apart and there was crap sitting in there.

And James..its about as complex and precise as making a PBJ sandwich.