Rebore sizes

[SteveW]

I've just dropped my block, head and crank off at the engine shop for inspection (thanks to Tim for the recommendation). It's looking as though the block will need a rebore. It's already at +60 thou and the next standard piston size up is +100 thou. TC Forever says that it's ok to rebore to this size rather than sleeve, but I thought that I would get a second opinion from the people on here. Also, what does turning it into a 1350 cc engine do for the driving experience?

They are also going to crack test my crank just to be sure even though the previous owner said he had it tested and it was ok. Fingers crossed as that is one part that I don't want to have to replace.

I've asked for the unleaded conversion on the exhaust ports in the head whilst they are at it - I had might as well get everything right now whilst the engine is in bits.

Looking forward to getting everything back and then starting on rebuilding the engine.

[Steve Simmons]

A friend of mine (Olson here on the forum) has a 1350. I don't know what else is in there but it runs like a scalded cat! He installed a 4.3 rear end and the car handles it well. When on tour, he can leave me in the dust on the highway. On a steep climb, he uses 3rd gear and we take turns passing each other. I go by him in 4th until my RPMs drop too far, then switch down to 3rd to re-gain some speed while he goes by. Then I pass him again and it starts all over. On a long climb he can usually drop me and disappear into the sunset.

That said, you may want to check bore wall thickness before going that big. I've heard there are variations in blocks that can lead to punching through on some but not others. Or, you can have custom pistons made in whatever size you want.

[Tom Lange, MGT Repair]

I've done two engines at +.100": one needed sleeves as the boring bar broke through into the water passage; the other worked just fine. I had the second block ultrasound tested to verify that there was enough meat there - if you plan to go +.100", it is worth doing that.

I would also look around for a set of +.080" pistons, which I know used to be available from non-MOWOG makers.

Tom Lange
MGT Repair