Author Topic: TWO STROKE DISC VALVES  (Read 654 times)

Alan Cooper

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TWO STROKE DISC VALVES
« on: April 02, 2021, 11:17:14 PM »
Hi.
I am looking for some advice on where I could get some disc valves manufactured and what would be the best material to use. They are for an Armstrong 350 tandem twin engine. I have a motor that I am rebuilding and the valves are badly worn where they fit onto the cranks. The reason I  am looking at getting some made is that I do not think there are any new parts left for these engines. I would be grateful for any suggestions on either the manufacture or source of new parts. Many thanks. Alan.

dave strong

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Re: TWO STROKE DISC VALVES
« Reply #1 on: April 03, 2021, 01:09:54 PM »
this might help https://www.rotax.co.uk/

Spen

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Re: TWO STROKE DISC VALVES
« Reply #2 on: April 03, 2021, 02:36:04 PM »
If you look at my profile picture, it’s of my wife on a similar machine......

Alan Cooper

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Re: TWO STROKE DISC VALVES
« Reply #3 on: April 03, 2021, 09:07:19 PM »
Thanks for the link to the Rotax sie. I had already looked at that. The valves are different. It may be possible to modify them but they have no stock anyway. The search continues.

Ian Warner

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Re: TWO STROKE DISC VALVES
« Reply #4 on: April 05, 2021, 10:49:15 PM »
Hi Alan, just a thought - have you made any enquiries via the karting communities - Bob Clews from Stoke on Trent did some Rotax work for me, but quite a few years back, don't know if is still on this mortal coil.
Ian.

Rob Wittey

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Re: TWO STROKE DISC VALVES
« Reply #5 on: April 06, 2021, 12:43:42 PM »
Could try Mark at performance fabrications, its mainly RG's he does but fabs alot of 2t stuff
http://www.performancefab.co.uk/

Robin Keating

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Re: TWO STROKE DISC VALVES
« Reply #6 on: April 06, 2021, 06:51:57 PM »
Goodafternoon Alan
I use CS80 spring steel on the disc valves in my Bridgestone, I then get them wire eroded to my design and spec and they have worked well for me over many years.
A word of warning it is expensive but you get exactly what you want, if you send me a PM with your Tel Number I will give you a ring.
Best regards
Robin   

howard langham

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Re: TWO STROKE DISC VALVES
« Reply #7 on: April 08, 2021, 10:02:45 AM »
I have some 24"x 6" sheets of the correct steel that you need, I got it from the original Konig factory in 1975 and still make my own Konig discs. You are welcome to have a sheet FOC if the size is correct (I do not know the size of your discs) they can be cut by hand with great difficulty but it is best to get them laser cut. Just let me know if you want one I am in York.

Andy Guy

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Re: TWO STROKE DISC VALVES
« Reply #8 on: April 08, 2021, 02:13:52 PM »
Try Richard Tracy, Ian Harrison and Phil Featherstone.
All on Facebook. There are lots of Rotax 256 kart pages on FB also.
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Robin Scudder

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Re: TWO STROKE DISC VALVES
« Reply #9 on: April 09, 2021, 12:40:00 AM »
A whole lot of Rotax engine parts from that era were interchangeable, gearbox internals could be swapped around between 125, 175, 250 singles and the twins, I think a lot of the case bearings were too.  It's possible that disc valves from any of the single cylinder engines would work.

Andy Guy

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Re: TWO STROKE DISC VALVES
« Reply #10 on: April 09, 2021, 05:48:43 PM »
Different drive Robin. I think the armstrong used yamaha parts for the crankshaft also.
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