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gear case cover uncertainty

Posted: Wed May 29, 2019 1:15 pm
by Brian Petheram
I am trying to complete a 1939 VH Red Hunter project from the Mike Taylour collection. It's an interesting challenge as some of the work has been done very well but some parts have clearly been thrown on to make it more saleable. Basically I'm disassembling pretty much everything to check it's correct so there may be more similar questions to come. My latest dilemma is the gear cover (or inner timing cover as I would call it) which I removed to check the valve timing. There are two threaded bosses on the lower side of the chain case which seem to have no obvious purpose - do I have the wrong gear cover or if not, what is meant to bolt on to the cover? The breather and oil inlet and outlet are all in place and apart from the bosses it looks similar to the illustration in the parts book. Photos below - any advice or suggestions welcome.
Cheers,
Brian

Re: gear case cover uncertainty

Posted: Wed May 29, 2019 2:23 pm
by dave.owen
It's correct for 39,
The threaded hole on right is a second breather, the rear hole is to secure to the engine plate from underneath.

Dave

Re: gear case cover uncertainty

Posted: Wed May 29, 2019 2:42 pm
by alan.moore
As Dave says. Bottom breather union is one with a 45 degree bend (rear one is 90 degrees). Rear boss bolts to the magneto platform.

Here is how mine looks..1939 VH
Just finished fully restoring mine so any questions just fire away

Cheers
Alan

Re: gear case cover uncertainty

Posted: Wed May 29, 2019 4:51 pm
by Brian Petheram
Thanks Dave and Alan for the prompt and helpful replies. It's good to know I have the correct part. It looks like the breather (part number 2100-33) may be a problem as Draganfly don't do it and it isn't listed by the Club Spares Scheme or by John Budgen. I will press on with assembling and hope a used one shows up as I assume it just bolts on from the outside.
cheers
Brian

Re: gear case cover uncertainty

Posted: Wed May 29, 2019 5:05 pm
by Bob.Murphy
Breathers aren't difficult to make, they use standard 1/4 BSPP fittings (from memory).

Bob.

Re: gear case cover uncertainty

Posted: Thu May 30, 2019 9:23 am
by Brian Petheram
Good point, Bob. If it is a straight through breather that will be doable even for me. However a close look at the 1939 parts book shows a reference to a ring and a ball for "valve in elbow union" which implies there may be some non return valve internally in the breather which would probably be beyond me. Another issue is that in the 1946 parts book the cover no longer has the 2nd breather below the case. Does this mean that the 2nd breather is not really necessary - it does seem odd to have 2 breathers venting so close to each other in wich case I could just block it off?

Re: gear case cover uncertainty

Posted: Thu May 30, 2019 8:48 pm
by paul.jameson
No, you don't need the second breather. I ran my 1937 RH for many years and miles with only the breather on the back of the case with no problems.

Re: gear case cover uncertainty

Posted: Fri May 31, 2019 9:19 am
by Brian Petheram
Hi Paul,
thanks for the reassurance, I will blank it off until one turns up as none of the usual sourcers seem to have any.