Piston to cyl wall clearence?
- Thread starter PorterzSupra
- Start date
I have Ross, and I have no slap whatsoever, even on a cold motor... I told the machinist Toyota motors were tight spec, but damn...
I've never experienced it!
I've never experienced it!
Rich: Good point but I don't think there is enough mass difference to make such a big step in clearance!
Adjuster
Supramania Contributor
I think coatings have something to do with how you determine clearances too.
Uncoated, 6k might be fine.
Coated it will make for a slap happy motor. (They don't expand as much, so you only lose the slap when you drive the motor hard and heat up the pistons to maximum temps.)
After building one with 6k on coated ROSS pistons that slapped forever, I'm somewhat happy with my 3k clearance on this current setup. The slap pretty much goes away when warmed up.
Pistons are coated like IJ's, thermal barrier on top, molydisulfied on the skirts and thermal dispersant on the under sides.
Uncoated, 6k might be fine.
Coated it will make for a slap happy motor. (They don't expand as much, so you only lose the slap when you drive the motor hard and heat up the pistons to maximum temps.)
After building one with 6k on coated ROSS pistons that slapped forever, I'm somewhat happy with my 3k clearance on this current setup. The slap pretty much goes away when warmed up.
Pistons are coated like IJ's, thermal barrier on top, molydisulfied on the skirts and thermal dispersant on the under sides.
so its more likely to slap if its too tight or too loose?
Whats the risk in running too tight vs running to loose?
Whats the risk in running too tight vs running to loose?
PorterzSupra said:
loose
PorterzSupra said:
too tight, the pistons could seize, too loose, they could slap & cause damage to the skirt of the piston.
Really, find the spec and take the pistons to the shop. That's the proper way to fit some pistons.