Bargains on ebay?

The theoretical ideal shape for a combustion chamber is a sphere because it has the minimum surface area for energy to be lost through heat conduction. That can almost be achieved in a conventional piston engine using inclined valves and bowl-in-piston designs, and it's why twin-cams are such a good idea. If you look at the combustion chamber of a Wankel at the moment of ignition, it's a long, wide, thin flattened banana shape with a massive surface area which is about as far from ideal as you can get, so unless they either come up with ceramic rotors and housings which don't need cooling, or they reduce the cost of petrol to £1 a gallon, it's always going to be a non-starter.

Which is why Triumph motorcycle engines and Chrysler 'Hemi' engines were powerful for their time, using a hemispherical combustion chamber. But combustion chamber design has changed a lot since, with the evolution of multi valve designs..

http://cgi.ebay.com/ws/eBayISAPI.dll...E:B:SS:US:1123

brilliant! i can so much see the constraints now! thanks Shane!

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Originally Posted by shane

The theoretical ideal shape for a combustion chamber is a sphere because it has the minimum surface area for energy to be lost through heat conduction. That can almost be achieved in a conventional piston engine using inclined valves and bowl-in-piston designs, and it's why twin-cams are such a good idea. If you look at the combustion chamber of a Wankel at the moment of ignition, it's a long, wide, thin flattened banana shape with a massive surface area which is about as far from ideal as you can get, so unless they either come up with ceramic rotors and housings which don't need cooling, or they reduce the cost of petrol to £1 a gallon, it's always going to be a non-starter.

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Originally Posted by Stubies

http://www.ebay.co.uk/itm/Rare-Recor...item3f28a4c00b

well, it is rare!

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The word "rare" is getting a lot of exercise on ebay these days :lol:

Hasn't anybody yet worked out that it could mean two things?

"I searched on ebay today and couldn't find another one so it MUST be rare"

or,

"When they were new they were a total bag of shite, therefore nobody bought them, hence why there aren't many around now".

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Originally Posted by Effem

"When they were new they were a total bag of shite, therefore nobody bought them, hence why there aren't many around now".

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ah ha! we have an understanding!!

:lol:

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Originally Posted by Effem

The word "rare" is getting a lot of exercise on ebay these days :lol:

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Frank - is your avatar a picture from the Blues Brothers? or perhaps Smoky and the Bandit?

:)

Couple of nice WD amps here, both from the same seller in Ely which isn't far from where WD was when Peter Comeau owned it, so I'd hazard a guess that the seller is associated in some way. Don't quote me on that though. He can't spell integrated either, which I always find unreasonably irritating.
http://www.ebay.co.uk/itm/World-Desi...item20d7388b90
http://www.ebay.co.uk/itm/World-Desi...item20d7385bc9



Nice turntable to go with one of them (but then, I would say that, wouldn't I? :)). Could be a steel chassis. Looks like it needs a bit of cosmetic help though.
http://www.ebay.co.uk/itm/1511106739...84.m1423.l2649



Lovely arm, but it this price he has to be joking, surely, especially as it isn't even complete?
http://www.ebay.co.uk/itm/2612748345...84.m1423.l2649

You wont find them much cheaper http://www.ebay.co.uk/itm/Mission-78...item3f28dd1ab1

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Originally Posted by Stubies

Frank - is your avatar a picture from the Blues Brothers? or perhaps Smoky and the Bandit?

:)

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It is Buford T. Justice (Played by Jackie Gleason) from Smokey and the Bandit