Jerry Howell V-twin build questions

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Well-Known Member
Nov 17, 2020
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Tadcaster, UK
Hi I'm currently building a JH v-twin and have some questions I hope someone will be able to help answer.
1. Sheet 22 shows a crankshaft bearing spacer. I assume that this goes over the shaft of the crankshaft, in-between the bearings in the crankshaft housing. I don't understand why this is needed and why it should be 3 thou larger than the actual gap. There is reference to the housing expanding more than the crankshaft, but I just don't understand the purpose of the spacer. Ironically I've already pressed both bearings into the housing, and it will be difficult to get one out. So if the spacer isn't critical I would prefer to leave it out.
2. Sheet 43 states that the crank pin is loctited into the crankshaft disk. But the other end of the crank pin is a slip fit at assembly into the hole in the tailshaft crankdisk, and not to loctite this together. I don't understand how this would be adequate enough.
If anyone has made a JH v-twin who can shed some light in these concerns I would be very grateful.
Did you ever find out the answer Andrew?
Regarding the spacer, someone left a comment on my YouTube channel suggesting that the spacer is needed to prevent sideways pressure on the bearing when fitting the flywheel. I don't want to remove the bearings by heating up the housing, so I plan to put a very small boss on the flywheel which will apply pressure on the crankshaft rather than the bearing.
I've also concluded that crank pin has to be a slip fit into the tailshaft crankdisk.
Thanks for enquiring.
Hi John
I'm not quite there yet - I got tied up with other life things. You can follow my progress on my YouTube channel. The link to my playlist is: