Question For Engine Builders

[boostn0199]

I have two std rb25 blocks with one of them comp 155 across all except for cyl 6 which has a stuffed ring. Is it possible to take the whole piston assemble from cyl 6 on tge other block and just stick it in with no machining or anything.

[Shoota_77]

You can but....

The best way to do it is by pullng all of the pistons out out the donor motor and measuring them, then measure the bore and pick the piston with the closest piston to bore clearance as per standard specs. Ideally I'd never recommend doing the as while it's all apart for another $600 and a hone you can put a set of brand new pistons and rings in and have a basically 'fresh' engine.

If you can, swap over the "new" piston onto the original rod and use the same bearings as what came out so the clearances should be the same. Again, you should put a new set of shells in while it's apart and plastiguage it to see what the clearances are at. A set of bearings will set you back $250-$350.

It's not everyday you have your engine out so you may as well freshen it up while you're in there.

[FBRacing]

If you're pulling the motor apart that far then go all the way. Give it new bearings, rings, and seals. It's not really much when you think it'll last you a long time until you want more from it.

[89CAL]

Yeah I would disassemble, clean, measure (Decide if it needs any machine work) then at least hone the bores and new rings, bearings, seals etc.