cutting piston liners to larger dimensions.

Hi guys, a quick question

Can you simply machine out liners to accept bigger pistons? Possibly considering going from 4.280 to 4.310 and wondered if it could be done by machining out our set of liners to accept bigger pistons.

I wasn't sure in case of finish treatments etc and cutting through them causing the liners to be softer to heat etc.

Hopefully this hasn't sounded a stupid question, but one I wanted to ask before possibly going about it.

Many thanks

 

Did that once years ago, they cut HARD! Worked though but wouldn,t do it again

 

KB used to do all of mine, till the price went up near what I sell new TFX sleeves for today.

 

I have had our local machine shop cut many 4.187" sleeves to 4.310".....I had them done in block....a little higher price as they had to make several passes with the boring bar....but works out just fine....check the OD on your sleeve register before you do this....I know KB stage 10 blocks came with 2 outer sleeve register options...4.515"/4.535" stepped (for smaller fuel bores) or 4.615"/4.635" stepped (for larger alcohol bores) - most engine builders seem to agree that the smaller OD sleeve is too thin for the 4.310" bore....not sure about other brand blocks...

 

Great, it seems this is standard practice with a lot of racers.

Just got off the phone to the piston company and they are making me some slightly oversized pistons. Best get the liners out and get machining!

Thanks everyone for your help!

 

Should talk to who is going to bore them, may want to bore them in the block.

 

Make sure your liners are at least 4.600 O.D. before boring.

The 4.5 O.D. are too thin at that bore.

Heat the block before removing them, too.

Way easier and better for the block.

Torque the mains, first, tho.

 

Finish them in the block.

They should be finish honed IN the block, we've made our own sleeves before and just left some stock in them for the finish hone.

Since you dont have far to go, from a 4.280 to 4.310 is only .030 I wouldnt even take them out, just let your machine shop do it. The guy I deal with has some pretty aggressive stones that will take .030 out in no time at all.