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VH crankcase joint

Posted: Tue Jul 28, 2020 8:00 pm
by Pete.Silson
I have a pair of crankcases for my 52 VH project but there is a long section of the lip on the crankcase mating joint missing.
crankcase joint.jpg

I find that, with the crankcase bolts hand tight, the two cases can slide sideways relative to one another. Will this be a problem for the crankshaft main bearing alignment? It seems to me that this is the purpose of the lip as the bolts have relatively large clearance in the cases.

Will it affect oil leakage though the joint?

Any advice/comments please.

Pete

Re: VH crankcase joint

Posted: Tue Jul 28, 2020 8:39 pm
by JohnnyBeckett
hi peter i would fit the barrel on to the cases to line up the cases and i would use wellseal on the joint to seal it and i think you will ok

Re: VH crankcase joint

Posted: Tue Jul 28, 2020 9:20 pm
by dave.owen
Peter, yes use wellseal,should be ok

Re: VH crankcase joint

Posted: Wed Jul 29, 2020 6:05 am
by nevhunter
IF they are matching cases and you want a really good job line them up exactly and have a hollow dowel fitted to one of the bosses on the side where the lip is absent. Then clean glue and assemble and it MUST be right. Nev

Re: VH crankcase joint

Posted: Fri Jul 31, 2020 6:25 pm
by paul.jameson
Check that the cases are indeed matching. If you look at the bottom of the cases, on one of the ribs for the crankcase bolts, one side or other of the sump plate, are stamped numbers. These are about 1/8" high and are the same on each crankcase half if they match.

The lip on the crankcase mating joint, damaged on your set of cases, is the critical item for ensuring the main bearings are in alignment. The lip sizes vary by a surprisingly large amount from set of cases to set of cases so odd crankcase halves are very far from interchangeable.

Re: VH crankcase joint

Posted: Fri Jul 31, 2020 7:59 pm
by Pete.Silson
Check that the cases are indeed matching. If you look at the bottom of the cases, on one of the ribs for the crankcase bolts, one side or other of the sump plate, are stamped numbers. These are about 1/8" high and are the same on each crankcase half if they match.

The numbers are the same on both cases and look genuine to my untrained eye. I am curious how this type of damage has been inflicted. The lip is fairly narrow but I would have thought that it would take some pretty heavy-handed treatment to break it off like this.

Pete

Re: VH crankcase joint

Posted: Sat Aug 01, 2020 12:44 am
by nevhunter
The thickness of the lip can vary depending on the casting inner dimensions. I've just recently rejected a case similarly damaged. You could weld it and remachine CAREFULLY but most likely it will distort enough to be a problem when you weld a fair distance along the edge.. IF you choose to hollow dowel it make the dowel stepped slightly so it will come apart without difficulty and you must achieve good alignment before you oversize one of the bolt holes. The dowel only need s about 1 mm wall thickness. Nev

Re: VH crankcase joint

Posted: Sat Aug 01, 2020 8:29 pm
by paul.jameson
Perhaps you could get that type of damage by knocking the case off the bench?

I think I would be considering replacement cases - which should not be too difficult to source.

Re: VH crankcase joint

Posted: Sat Aug 08, 2020 5:52 am
by wade.edwards
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Can be done

Re: VH crankcase joint

Posted: Sat Aug 08, 2020 6:43 am
by john.whiting
A lot of work /expense for very little benefit......if there is enough of the original register to locate the castings ,then that is sufficient...........Similar to the crankcases.......the barrel recess bore and remains of the ledge are quite sufficient to locate the cases,and once properly tightened there is no way the assembly will move......use one of the modern sealers like orange silastic ,and there will be no leaks .