1BIGJIM

iTrader: (1)

Moisture from reversion will not wash down cylinder walls, fuel washes down cylinder walls.

Baja Rooster

iTrader: (1)

True.

I emailed Total Seal and they recommended #T9190 225 cast iron rings with the second ring being gapless. I measured things out and have .003 clearance, fwiw. N/A

https://www.summitracing.com/parts/tsr-t9190-225

I would’ve expected moly rings, and haven’t heard the OSO brain trust being too impressed with the gapless setup.

Any thoughts on this?

snapmorgan

iTrader: (2)

.003 is pretty tight. I would personally rather see .005, but if it was running that way with no piston scuffing, it will do so again. As far as the rings, I have used the gapless rings with no issues. I don't think they help performance, but I don't think they will hurt it either. I would trust the ring manufacturer. They know more about it than anyone.

Baja Rooster

iTrader: (1)

Thanks, Snap.

I measured the pistons at 4.462 1/2” above the bottom and the bore at 4.465, but I was using the T bars to measure the bore and had a heavy thumb on the calipers, so it could easily be the standard 4.466 bore leaving .004 clearance.

I contacted JE for their recommendation on rings, and they said they supply the pistons to GM but not the rings and to pretty much just piss off.

Is this the correct place for the part number?

snapmorgan

iTrader: (2)

http://www.jepistons.com/TechCorner/HowToIdentify.aspx

Baja Rooster

iTrader: (1)

I’ve looked all over it for another number but can’t find one. Would you consider this scuffed?

Baja Rooster

iTrader: (1)

And the bearings are toast. I pulled the #2 main cap off and it has a groove in it. It did have good oil pressure though with 75# at cold idle. It would drop under 20# at idle after a long run and pop back up to 40ish after a moment.

snapmorgan

iTrader: (2)

piston looks fine. looks like the crank is going to need polished though.

Baja Rooster

iTrader: (1)

Earl Johnson said those bearings were too tight from the factory, so hopefully a good polishing will be enough to clean it up and will also help set the clearances. I finally found the very specific rings for this piston, so I’ll drop the crank off for polishing and perhaps get the block honed with a torque plate. They don’t hone with a torque plate at the factory but clearances appear snug so there *may be enough material there to do so.

Baja Rooster

iTrader: (1)

A quick platiguage check on #2 main and #1 rod show a snug .002. Should be aiming for about .0025 rod and mains and about .003 on the #5 main, yes? Taking the crank in for a polish/check soon.