[steve25]

Since there’s now been a good amount of grit flowing around in the motor once your tare it down inspect the piston skirts for imbedded grit and of course scratches.

Also pull the oil galley plugs so a hot tank session will remove any hung up grit that might be hiding in there, especially if there’s old sludge in there.

Be sure to take the oil pump apart and check for scratches on the pump cover and gears and double check the bypass chamber for grit.

Once you get it all good and running again you will be surprised how much faster the motor will rev up with the lighter aftermarket rods in there!

[JLMounce]

Originally Posted by steve25

Since there’s now been a good amount of grit flowing around in the motor once your tare it down inspect the piston skirts for imbedded grit and of course scratches.

Also pull the oil galley plugs so a hot tank session will remove any hung up grit that might be hiding in there, especially if there’s old sludge in there.

Be sure to take the oil pump apart and check for scratches on the pump cover and gears and double check the bypass chamber for grit.

Once you get it all good and running again you will be surprised how much faster the motor will rev up with the lighter aftermarket rods in there!

I would simply plan on new pistons as well. These are original TRW forgings. Strong, but certainly heavy and old tech. It would be really nice if the cylinder walls could be honed only, but if I've got to go another 10 thousandths I'm sure that's not a huge issue.

I'd like to get a modern ring pack in there and I'll probably go with a gapless top ring.

Hopefully the pump is okay and can be cleaned. It was just installed last year.

WIth a rebuild I'm going to do what I've wanted to with this engine in the past but didn't have a big reason to.

My plan would be as follows
-Retain the factory crank. If it's not salvageable I'll go to a forged 4.25" crank.
-Forged rods to support some additional power and rpm
-New forged pistons with a more modern ring pack
-Roller cam, either Johnson lifters or topped by HIPPO solids, something in the low 240's on the intake side, probably using UD lobes.
-Have the heads gone through, to include a decent port along with porting and matching the TII, move to 1.6 rockers.

Basically I'm thinking of it as kind of a max effort street D-port engine. I don't have any vacuum accessories that I need to power, so I can go a little larger on the cam. The drivetrain is built to handle around 700 hp. I'm not going to get anywhere near that, but if I could pull up to around 570 or a little beyond, I think that would sit in the platform nicely. Any more than that and I think I'm going to be in a traction deficit.

The block is drilled for 4 bolt mains. I don't know if I need to do 4 bolt caps at this power level, but I might go to studs regardless for a bit more piece of mind.

Idea here is to do it once, do it right and not cut corners.