1gr-fe 2015 Tacoma Overbore Cylinders?

Got hold of a disrespected 2015 Taco with 93k. Shit the bed around 98k. Super low compression in cylinders 2 & 4. Around 40/60psi from compression test in each, and would only hold about 25/35psi in a leak-down test. There is enough wear/warp on the cylinder walls that a hone won't fix the problem. Can only speculate what caused it. My guess is the previous owner must have ran it dry, flooded it, or it chewed up something mighty nasty. Maybe all three.

Does anyone have experience with machining the 1gr-fe? The steel sleeves in the block seem quite thin, so not sure. Is it possible to overbore that block 0.020'' with those sleeves? Are they just going to crack after a few hundred heat cycles?

 

I know of 1 guy that has built 1GR.
You might ask over here.

https://www.tacomaworld.com/threads/torspd-nevr.203482/page-2#post-4530164

 

nice man! I'll check it out. Just herd from my machine shop. They sonic tested the block and found that at the thinnest point the sleeves were about 114 thou. so going 20 over will be fine...hopefully.