2jz piston to wall clearance.

I know this has been discussed 100's of times, but I can't find a specific answer. Im busy building a 2jz, the motor was originally built for drifting, I did not originally build this motor, but as far as logic takes me, drift cars spend a lot of time on the limiter under boost and piston to wall clearances are a bit larger than usual. The motor is currently at 86.5, I bought the motor with a single melted piston due to a clogged injector. I spoke to CP and they'll sell me a single new piston and a set of rings. They're 8.5:1 off the shelf pistons. Now, the cylinder walls didn't have any scoring so Im just sending the motor to be torque plate honed in the bores. When do piston to wall clearances become too big? Im putting the engine into a street car now and Im aware that it might be a little noisey on cold start, but could I have any adverse affects? I guaged the piston to wall clearances to be at about .135mm (0.00531inches) in cylinders 1-3 and further back they get larger, where the largest is at .162mm (0.00637 inches). Will this motor be safe run after the re-hone? I'll be sure to give it plenty of time to warm up before I drive it. But how big is too big?

Well, normally CP recommend 0.09mm for these positions but if the engine is going to see lots of abuse such as drag racing or drift it would be wise to stay on a safe side up to 0.13mm. Anything more than that is too much in my opinion... Going too much on the piston to wall clearance can cause blow by and faster wearing off the piston skirt.

So I expected to see accelerated wear, but would it he safe to use this engine in a "daily driver/canyon carver"? How accelerated is accelerated wear, can I reliably see 5 years of use from it? We're hoping to make 600whp from it. If I monitor oil usage from it and notice an increase in oil usage to excessive amounts, Ill rebuild it again and go to 87mm bore and new pistons, but should I fork out the money for a whole new set of pistons, boring and honing now, or could I drive it and use it normally for time being, with the occasional top speed run and roll race.

So I expected to see accelerated wear, but would it he safe to use this engine in a "daily driver/canyon carver"? How accelerated is accelerated wear, can I reliably see 5 years of use from it? We're hoping to make 600whp from it. If I monitor oil usage from it and notice an increase in oil usage to excessive amounts, Ill rebuild it again and go to 87mm bore and new pistons, but should I fork out the money for a whole new set of pistons, boring and honing now, or could I drive it and use it normally for time being, with the occasional top speed run and roll race.

It will be safe- nothing is going to blow up or anything like that but eventually you are going to end up with very high oil consumption. By the way, if you are re-honing the cylinder walls you better off to get new piston rings for all pistons and do proper engine brake in procedure. It will help you to seal cylinders much better and postpone increased oil consumption for a long time.

That was the plan from the start, to start with a complete new ring pack and just run it until I see that it would be time for a new set of pistons. Thank you for the insight.