Author Topic: Timing case breather  (Read 833 times)

Offline Sakura

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Re: Timing case breather
« Reply #15 on: 27.03. 2023 21:32 »
Hi Musky, SRM do a modified engine sprocket nut with provision for a degree disc and I have already ordered one. Going back to the engine breather, do you think there's any value in putting a check valve in the tappet cover breather to blow not suck in conjunction with the timed breather?
63 RGS

Online muskrat

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Re: Timing case breather
« Reply #16 on: 27.03. 2023 21:48 »
G'day Sakura.
It wouldn't hurt only allowing inwards flow. It would need to be a very light check valve (open with a fly fart).
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Muskys Plunger A7

Online Colsbeeza

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Re: Timing case breather
« Reply #17 on: 28.03. 2023 03:37 »
Hi Sakura,
I fitted the SRM cush nut which has two threaded holes in it to mount a small disc which SRM supplied together with the mounting screws, but I found it a bit small for accuracy when set statically. I purchased a standard disc made by Wassell ( readily available or you can print one yourself from internet images) which is much larger and easier to set the timing as accurately as possible statically. The disc ID looks a bit rough as I cut the hole larger with snips. I don't have a strobe like Muskrat, so the larger disc suits me. My glasses don't have to be the bottoms of Coke bottles to see the markings. *eek* I must remove it afterwards of course whereas muskrat can leave his on.
Col
PS. That gear in the background is the electric starter gears.
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Online groily

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Re: Timing case breather
« Reply #18 on: 28.03. 2023 06:35 »
If they're any use to anyone, printer-friendly versions, clockwise or anti-clock, 1° gradations etc and other features as described in the accompanying text, are available here. 180mm diameter so fit on a bit of A4 paper (or card for them as has got printers that'll take it).
http://www.brightsparkmagnetos.com/downloads/index.htm for some choices
or
http://www.brightsparkmagnetos.com/downloads/TD01/ferkt839tjv4ng89v456ng455t.pdf for the generic one.
Bill

Offline Sakura

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Re: Timing case breather
« Reply #19 on: 28.03. 2023 17:12 »
Hi Musky
Looks as if I can get a check valve that opens at 0.2 atmospheric. To me that's about 3lbs. That seems quite heavy. Your thoughts?
Thanks for all your other advice guys, much appreciated.
63 RGS

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Re: Timing case breather
« Reply #20 on: 28.03. 2023 20:35 »
G'day Sakura.
3Lb does sound a bit heavy, won't hurt to try.
I have the Bunn Breather on my Cafe. In at the top, out at the bottom which is apposite to the recommended way as the top end is the hottest so I wanted cold air in there.
 Pitty Rex stopped making them years ago. I went hunting for info on the valves and found a shop in Brisbane with a kit for sale. https://www.britishmotorcycle.com.au/store/engine/oil-and-fuel-line-etc/bunn-breather-kit/ I'll ring them today.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Offline Sakura

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Re: Timing case breather
« Reply #21 on: 28.03. 2023 21:23 »
That's kind of you Musky but I'm in the UK so I will try to source one locally. When I built the engine of my RGS in 1990 I built the engine to be bullet proof, having put a rod through the crankcase of a M2 Spitfire and RGS cases are half of the heart of the bike.So, brand new crank with SRM crank end feed and nitrided, Carillo rods, new 357 cam, new followers, unleaded valve seats, racing valves and springs, rebored, belt drive dynamo, balanced crank etc. When I sold it in 1997 (instantly regretted) it had done 6,700 hard miles. When I bought it back last week it had 8,109 miles on the Speedo, backed up by MoTs, in 26 years!  What a waste! But good for me. *smile*
63 RGS