engine crankcases

[efkruger]

Gentleman,
Does anyone know for sure if crank case halves are matched? In other words is it correct to say that they were machined together when they were manufactured or can you mix them and they will still be inline? I have been concerned that if I mix halves that alignment of bores might be off creating some misalignment of parts. Any advice or thoughts on this would be appreciated. Thanks

[hodakamax]

You can replace either side, all should fit of the same model.

Max

[Hydraulic Jack]

They may have been machined for each other, but I doubt it makes much difference. Cases are sealed with anaerobic sealant which accounts for small differences. Make sure neither case is warped and the mating surfaces follow each other if you mix case halves. I suppose you could pull the alignment dowels and flat sand the cases but I dont think it would be necessary.

[Bill2001]

So they use C3 bearing fits?
I can see more elbow room on the trans shafts with one ball brng and a bushing.
But seems like the main/crankshaft brngs might be pickier unless the case bore fit is quite loose.

[Bill2001]

So they use C3 bearing fits?
I can see more elbow room on the trans shafts with one ball brng and a bushing.
But seems like the main/crankshaft brngs might be pickier unless the case bore fit is quite loose.

[Hydraulic Jack]

C3 refers to internal tolerance larger than normal, not external dimension. C3's are often used in high heat applications. Whether the crank bearings should be C3 I don't know simply because Hodaka never said so, but I wouldn't be surprised that C3 is appropriate on the crank. All others can be standard tolerance.

If bearings are not a snug press fit in the crank bearing bosses, the cases are damaged.