TOPIC:

I'd appreciate opinions on this, or even better if someone has done it before.

I have a damaged set of MTC "J" engine 10.5:1 72mm bore pistons. And a good set of Wiseco for the same application. I hate the circlips (pain in the ass) and the groves have been scored from a previous installation. 

I want to use the MTC pins and buttons in the Wiseco pistons. No fit problem since both are 17mm for a 72mm bore.

Two issues:

One is the MTC wristpin is shorter to fit the buttons. I'm not really worried about that since the wristpin bores on both pistons are very similar in length and thickness. So if the shorter pins are good in MTC they should be good in Wiseco. 

The big question is wristpin oiling. The MTC has a simple hole drilled though the bottom of the boss for splash oiling, and a passage from the oil ring groove to the top of the pin for a scraping oil feed.

The Wiseco pistons only have two gullys ground into the length of the bore for splash oiling from inside and out. 

My question is will the teflon button obstruct the splash oil from the outside? With the clips in they kinda make a dam at the outboard side of the gullys anyway. So I'm wondering if the inside splash is more than enough. At the same time, with the clips gone there's actually a passage by the buttons through the circlip install hole, to the circlip groove, and to the gullys. 

I'm probably over analyzing. And I also have an option to increase splash oil from the bottom by drilling a hole in the boss.

There should be no issues doing as you plan and if you are concerned about the oiling then just drill the Wiseco piston boss to match the MTC's
Most wrist pins are a tight fit in the pistons anyway with the pin and little end being the pivot.
 

wrote:

There should be no issues doing as you plan and if you are concerned about the oiling then just drill the Wiseco piston boss to match the MTC's
Most wrist pins are a tight fit in the pistons anyway with the pin and little end being the pivot.

 

Yeah. I'm thinking the same thing. Maybe flip a coin on drilling the holes. The MTC pins are about 5mm shorter to make room for the buttons. I don't think that should be an issue either.