WC rear top engine mounting bolt

[machten]

Hi all,

has anyone got one of these they'd be willing to part with...



Mine was just a piece of threaded rod that stripped the threads before I tightened it to "enough". I've put some more threaded rod in there for the hill climb this weekend and I'll be away for 4 days, but thought I'd put this out there now.

Regards,

Kev

[machten]

OK, I'll take as as a "NO". Next question is , "What should I use?"

Kev

[Rick]

In the US I would probably use a 5/16" bolt, only 0.002" smaller diameter than 8mm. The overall length and thread length combination will be hard to find, but worst case you'd buy a longer bolt that doesn't have enough threads after being cut down, and then run a die down it to get the correct thread length. Not much tensile load on the bolt so I wouldn't worry about buying a high test bolt, but it wouldn't be foolish to use the best bolt you can find. If you can find a longer 8mm bolt and cut down/rethead it, better yet- a threaded rod with a nut at each end would be my last resort choice- bare threads fretting against the hole in the soft crankcases would probably auger out the crankcase hole. Or, a piece of 8mm rod and run threads on both ends.
Your MK3D looks great.
Rick

[Jon Pegler]

I think Joe Carter at BSAnut sells the rear engine mounting bolts in stainless, at a price.
If you are stuck, go to a car breakers yard and use one of the head studs from a post 1970 VW beetle (Bug) or bus fitted with a 1600cc motor.
They used 8mm high tensile head studs, in three different lengths, and one of them fits a widecase frame almost exactly.

Jon

[machten]

I think Joe Carter at BSAnut sells the rear engine mounting bolts in stainless, at a price.
If you are stuck, go to a car breakers yard and use one of the head studs from a post 1970 VW beetle (Bug) or bus fitted with a 1600cc motor.
They used 8mm high tensile head studs, in three different lengths, and one of them fits a widecase frame almost exactly.

Many thanks Jon. Exactly the info i was looking for.

Kev

[machten]

Rick,

I was rushing through after riding back through 700km of thunderstorms from the Albany hill climb and missed your post. Thanks for that info too. I had a little bit of encourgement last night when I heard the the M3D won the "Best presented bike" for the hill climb. Personally I think it is all a phallic reaction to the twin filler caps . My wife maintains that is the primary reason for my attraction to that bike! She might be right!

Kev

[machten]

Finally got around to acting on Jon's tip re the 1600 twin port VW cylinder studs for the w/c upper rear engine mounting bolt.. As there was 4 of us wanting a couple each we bought a complete kit with 9 studs of the right length (and a few others that I'm sure will come in handy for something down the track) for AU$92. As Jon said, they are a near perfect fit at 240mm total length. (The original bolt was 226mm plus head height.)



Thanks Jon and Rick for your help.

Kev

[machten]

As there was 4 of us wanting a couple each we bought a complete kit with 9 studs of the right length (and a few others that I'm sure will come in handy for something down the track)

Interestingly, the smallest studs are 185mm which are perfect for a friend's 60's MV Agusta single!!!

Kev