fatjoe10

Honestly, I really wanna stay with the 87.25mm piston choice, but the block I'm using is so out of round and scored that they said +.25mm may not cure it. The 2nd block I'm building will get a very light finish hone but no overbore and will run OEM factory pistons with an APC coating to tighten up the clearance. I'm running 2 mules here :P

Slowcrash_101

Lets look at things with logic, an unmolested bore is 87mm the FRM liner is .5mm his piston is .5mm over. When the cylinder is bored out .5 over there won't be .2mm which is the boring service limit, but rather you will have ended up removing the FRM sleeve entirely. If the bores are that messed up, you might as well sleeve the block, at that point FRM pistons become a moot point unless you can find FRM sleeves.

Charper732

I didnt realize he said 87.5...thought it was .25

so yeah, that block will literally be a boat anchor with no liner at all...

Car Analogy

Which brings up a question I've wondered, why doesn't anyone make FRM sleeves?

Slowcrash_101

They do, they're not cheap though.

fatjoe10

There is also the option of Nikasil plating the block after sleeving, but as correctly pointed out, it is very expensive. There are a couple of folks running Nikasil plated liners in the 2ZZ engine, which also has this MMC material problem.

fatjoe10

fatjoe10

So I came across a block that could be bored to 87.25mm, so I placed an order for the corresponding Nippon Racing pistons. Obviously these are nowhere as nice as the OEM units, but I'm curious to see how far these can be pushed before destruction. The PZX piston has been APC coated on the skirts and thermal coated on the crown. That piston will be running in a different mule.

jackmugen02

WPC Treatment is another option, you can read a few articles on Moto IQ about it.

fatjoe10

Very nice information! I would be interested in WPC for engine bearings. Thank you so much!