showmerc.com

Well one day not to long ago my Hyper .21 finally died and I decided to let Mitch take a shot at Resizing the Sleeve....

He had been talking about doing this for quite some time so he finally gave it a shot on some of his old sleeves. I had seen one of his engines run that he resized and I knew immediately that I had to have mine done. I figured what the heck my sleeve is already shot so if he destroys it or it comes back as a lame duck, so what! I gave him 2 sets of pistons and sleeves and told him good luck because you could basically push the piston all the way through the sleeve on both of them I figured there would be no way he could fix either of them.

Well a couple days went by and I met him at the local LHS to get my parts back. He explained to me a little bit how he made a special mandrel to squeeze the sleeve perfectly all the way around while keeping it perfectly round at the same time. He said it took a couple days to make the mandrel for the Hyper sleeve because sleeve's tend to vary a bit from company to company and he didnt have on for the Hyper yet. As he was talking to me I was playing around with the P/S and I couldnt believe how tight the piston got toward the top! It would basically get stuck about 3/8 of an inch from the top of the sleeve which if you think about it is a little tighter than when a P/S set is new...

Well I finally got it home and installed it back in my block. I knew ahead of time that I would have to Re-break in the P/S so I ran about 3 tanks of fuel through it at slow speed. I kept a close eye on the temps which ranged from 190 to 230, the outside air temp was around 78 and I had the engine fairly rich. Well to make an already long story short I leaned it back out to normal settings by the 5th tank and I couldnt believe the power! I would have to say that a pinched sleeve would easily rival an brand new one. Many people have seen my truck run since I had this done 3 months ago and its still going strong, as a matter of fact I just recently ran it at a bash and mitch himself said he couldnt believe the sleeve was holding up.

Bottom line, If you have $12.00 and your engine sucks because its worn out let mitch pinch the sleeve. Better than payin $40.00 to $80.00 for a new one. Visit MotoMitch Website.

I don't have an old picture to show how the piston would go all the way through but as you can see from this pic the piston gets tight way before it gets to the old wear line.