Liners/Nikasil

[spork2367]

I'm talking with a company about the possibility of replating pistons and liners. Their concern was keeping the liners round for honing. How were the liners originally held for honing? Would a fixture block with a light press fit, that simulated the fit in the block, be sufficient?

[A26B]

It depends on the device you would use to hold it while honing, i.e. 2 jaw vise or 3 jaw chuck. The 3 jaw being best but also the most complex. FOr either style, I would recommend soft jaws that have been bored to the same I.d. as the upper ( largest) diameter of the cylinder sleeve.

For a 2-jaw fixture, the jaws could be cut from a single block of aluminum, say 10"x10"x2", then cut in half. Leave them "floating" to align with the sleeve.

For a 3-jaw chuck, make a set of blank soft jaws that will bolt to the chuck. Then chuck up a slug at the rear of the chuck jaws & bore the 3 mounted soft jaws to the correct dia.

It's not going to take much clamping force to hold the sleeve for honing and no more than necessary should be used. The sleeves are a "slip-fit" into the block, not even a light "tap-fit". So it's not necessary to clamp the sleeve tightly to simulate installed conditions.

The real force on the sleeve comes axially from the clamp force applied when the cylinder heads are installed. Consequently, the sleeves would need to be installed and a torque-plate used to duplicate the installed conditions, then honed.

It's going to require a diamond hone to cut nikasil.

[spork2367]

Originally Posted by A26B

It depends on the device you would use to hold it while honing, i.e. 2 jaw vise or 3 jaw chuck. The 3 jaw being best but also the most complex. FOr either style, I would recommend soft jaws that have been bored to the same I.d. as the upper ( largest) diameter of the cylinder sleeve.

For a 2-jaw fixture, the jaws could be cut from a single block of aluminum, say 10"x10"x2", then cut in half. Leave them "floating" to align with the sleeve.

For a 3-jaw chuck, make a set of blank soft jaws that will bolt to the chuck. Then chuck up a slug at the rear of the chuck jaws & bore the 3 mounted soft jaws to the correct dia.

It's not going to take much clamping force to hold the sleeve for honing and no more than necessary should be used. The sleeves are a "slip-fit" into the block, not even a light "tap-fit". So it's not necessary to clamp the sleeve tightly to simulate installed conditions.

The real force on the sleeve comes axially from the clamp force applied when the cylinder heads are installed. Consequently, the sleeves would need to be installed and a torque-plate used to duplicate the installed conditions, then honed.

It's going to require a diamond hone to cut nikasil.

I've installed one set of sleeves, so I realize they are a tight slip-fit. The company I called was worried about holding them and keeping them round. I think a block of aluminum bored for a tight slip fit, like the block, with a torque plate on top would be the ticket. They they can clamp or hold the block however they want.

[rkreigh]

I'd stick em the block and use the torque plate to hone them

anyone need some stock liners to experiment with?