djkak
I've never heard of this happening without the head gaskets getting blown out. Even if it's only a few thousandths, the movement against the heads is just enough to cause a head gasket to leak and once they do if you don't shut the bike down almost instantly, they blow out. S&S had some issues with their cylinders doing this a few years back. I don't know if they put out a recall, but if you had one come loose, S&S would pay for the shop work at one of their licensed dealers. Cycle Visions did a complete top end for a bro of mine and S&S picked up the tab. Ok, I'm wandering a bit. The point is, I don't see how the liner could move without the heads moving as well. IMHO Anyway, since the liners are press fit, I can see it happening if they aren't being staked properly.
B B
You’re right Spiderman, when the liner shifts reducing the clamp load on the head gasket fire ring, the game is over. The head continues to be supported by the aluminum cylinder, but the clamp load on the fire ring is lost as the liner moves down the cylinder into the crankcase.
The liners are cast into the aluminum cylinder at the Foundry when the cylinder blank is made. I am sure that bonding the iron liner into an aluminum cylinder is a delicate process that requires careful preparation and precise temperature control; maybe some incense and a wicked chant; possibly a mask and a little dance; don’t know exactly. A press fit alone between the aluminum cylinder and iron liner would not be adequate, especially over the long term because of the different expansion rates of these materials.
Regarding S&S, when the EVO Sidewinder kits first came out, the head gaskets were not sourced through a large, mainstream Vendor like James. For several months S&S supplied head gaskets made out of a red fiber material which did not have a steel fire ring. Instead of a fire ring, S&S machined a step into the head gasket surface, allowing the cylinder liner to protrude above the gasket surface approximately 0.010” (10 thou). The step was intended to apply additional clamp load to the gasket around the cylinder’s liner.
These red gaskets would fail almost immediately and the folks with these machines were forced to run them until S&S came up with a better gasket (sounds familiar). The next iteration of head gasket was a Teflon coated, fire ring equipped gasket that I believe was supplied by James. This gasket was the answer and took care of the leakers.
For years S&S continued to manufacture the cylinders with the liner protruding above the gasket surface, they may still make them that way; I haven’t looked in a while. Over time the protruding liner was eventually forced down through the cylinder and into the crankcase. After seeing the first couple of machines come back with this condition, I began cutting the top of the liner off flush with the head gasket surface prior to installing the cylinders. This would buy additional time before the liner finally let go. I probably saw a half a dozen 96” EVO Sidewinders with loose liners; I have never seen an EVO Sidewinder built prior to 1997 with more than 30,000 miles that has not had issues with loose cylinder liners.
A Foundry issue would explain the 110’s head gasket leakage but you would think that there would be issues with the other cylinders as well; especially if the problem extends across a broad date range.
I’m going to lay in the weeds a little longer and wait for someone to confirm that they have experienced some movement with a cylinder liner; hopefully with some good photos.
Again Spiderman, I hope your situation at home remains stable, with you and your family out of harm’s way.
djkak
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Topic: 110 Cylinder Liner Movement (Read 16003 times)