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I will cover the stones with thick layer of duct tape and thick layer of felt over that. Ill probably make holes in stone carriers to fix felt with wire.
My engine is still to be disassembled and then inspected. I'm not sure, if I really have get the cylinders honed. The 3.0l crank is already in stock and waiting to be installed.
If the cylinders are all good it's probably worth having them lapped at least. I think Lindsey sell a shim to cover the score on the rear main seal surface on the crank.
Thanks, I will do it this weekend. IVe read a lot of literature on the topic and longer silicon paste lapping should do no harm.. In fact it can even save piston rings a bit since the rounder silicon particle in block get, the better for the rings.
I used same procedure on my 87 S. Rings seated very fast and compression is within 2lbs on all four. As long as the pads stay on you are golden. If they come off and the stones hit the bore........well then you are in a sad place ..
I stitched the pads together at the back with a leather awl and heavy thread. There is quite alot of friction working to take the pads off.
Good luck!
I will put few stitches on the back side too, didn't find strong enough thread yet. I have glued the first ply of felt directly to stones and tried to remove it by force, no-go. Hot glue really works well with felt, but still, safety first.
I have made the lapping tool out of standard spring loaded drill honing tool, and since the tool had its stones glued on the carriers with hot glue, I figured this kind of glue should be strong enough bond to stone and carriers, so I tested similar glue on felt where it also gave excellent result, two pieces of felt glued together with hot glue are inseparable, no way of tearing them apart at room temperature.
Then I glued first ply of felt to all available surface and on it I glued another ply, but I only glued the second ply on the sides and not on the face side. This was done for failsafe in case the glue or felt let go, it would first fail at the weaker link and second ply would protect stone from landing on cylinder.
The bond however was so strong, I could do at least 5 more cylinders with the tool, perfectly stable.
I used Pattex hot glue sticks.
Then I took the AN-30 paste and snce the paste is very dense, diluted it a bit With Krown oil (gun&fine machine oil), to form a thick fluid instead of paste which is too thick to work with. I added aprox 10~15% of oil.
Then I applied this mixture to a cylinder (one at a time)
Then I oiled and applied AN-30 mixture on faces of felt tool, set the timer to 1:30 and started the laping procedure with powerful hand drill (boschhammer). Regular drill is too weak.
I tried to stay at about 200RPM and stroked it at a relatively fast speed (for hand lapping) about one to two strokes per second, did not use anything for stop at bottom of cylinder, shape of bottom end gives good feedback about when your strokes are too deep.
Pad pressure was set on the stiffer side, but when stiffness is set over a certain point or AN-30 paste is too thick, pads begin to vibrate in the bore, so pressure should be set to a point where this doesn't occur and sliding is smooth.
After the 1:30 I finished with a slow stroke pass at same speed then remove the paste from cylinder with clean cotton rag then cleaned it agan with another rag soaked in cleaning gasoline, lightly oiled it and that is it.
I will wash it with hot pressure washer before assembly, to really remove any trace of the paste from the block.
03-13-2015, 03:34 PM
Felt is glued on the stones and carriers with hot gun glue. Very stable.
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