precisionsc54

GSR block: bored, decked, - 81.5 mm bore
- Piston-to-wall clearance: .004
- Wiseco 81.5 mm (B18C) pistons Part # K541M815
- Wiseco Rings (came with the pistons) Part #

Now my question is this. The machine shop told me that the rings came pregapped at 12thousands. What kind of actual gap should I be looking for? Also how far down in the sleeve do you put the rings to take the measurement. I plan on making 400-450hp on a turbo setup. I know wrong forum but you guys are more helpful

DonF

Check them yourself to see what they are. Only a feeler guage required. If the bore is round and has no taper you can check anywhere as long as the ring is squared. Use your turbo piston to push the ring down 1/2 inch and check. Doubt they are .012.

vinuneuro

Huh..how do you pre-gap rings.

mar778c

iTrader: (1)

Wiseco recommends

Top ring 0.005Xbore
Second ring 0.0055Xbore

See link below
http://www.wiseco.com/Catalogs/Sport...ccessories.pdf

mar778c

iTrader: (1)

Follow this instruction.

Like Don said make sure the ring is seated properly.

vinuneuro

Ring gap is dependent on bore size. Saying that they're "pre-gapped" suggests that they come gapped 'correctly' from the manufacturer.

mar778c

iTrader: (1)

No, that pre-gap is based upon a single application. Look at the pdf in the link I posted for the OP. There are 5 different gaps/bore sizes. How can you pre-gap something when you don't know the application?

PyroProblem

You should still check the ring gap...measure twice and cut once.

precisionsc54

thanks for the help guys. I called wiseco today and they gave me the correct ring gap to run at 20lbs of boost.
.017-.019 for top compression rings and .019 - .021 bottom compression rings