fran9r Posted July 19, 2010 Report Share Posted July 19, 2010 I'm trying to find a parallel twin cylinder head, preferably air cooled, with the cam drive at one end. Any ideas? If not, how about a 4 cylinder head with the same end cam drive? GS500's drive is in the middle... Link to comment Share on other sites More sharing options...
bigkev Posted July 19, 2010 Report Share Posted July 19, 2010 What about the Kawasaki W650 i think it was called, aircooled but not sure if it was OHC made to look like a pushrod or actually a pushrod motor. Link to comment Share on other sites More sharing options...
David W Posted July 19, 2010 Report Share Posted July 19, 2010 TRX850 twin? Diversion 900 four? Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 What about the Kawasaki W650 i think it was called, aircooled but not sure if it was OHC made to look like a pushrod or actually a pushrod motor. Long stroke, classic style, big MPG. Hmm, you may have cracked it! It if was a DOHC (ideal, not essential) and cheap (can't seem to find any, not plentiful) it would be perfect. Think I'll have to keep a look out for one of them! Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 TRX850 twin? Diversion 900 four? TRX/TDM sounded interesting, but possible a bit too closely spaced. Good call though. I'll take a look at the XJs. Link to comment Share on other sites More sharing options...
Evilchicken0 Posted July 19, 2010 Report Share Posted July 19, 2010 XJ the cam was in the middle. GPZ 900 R was on one side Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 XJ the cam was in the middle. GPZ 900 R was on one side On a 4 cylinder, it wouldn't matter, I'd be hacking it in half anyway. Link to comment Share on other sites More sharing options...
DesmoEddy Posted July 19, 2010 Report Share Posted July 19, 2010 Where's the cam drive on the latter-day Laverda twins? Such as Alto racing used to campaign before the Vyrus? Eddy Link to comment Share on other sites More sharing options...
kaighn80 Posted July 19, 2010 Report Share Posted July 19, 2010 whats it for might give us a better idea as to what your looking for, what about the jap lumps they produced based on the old english bikes like trumps and bsa's? Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 whats it for might give us a better idea as to what your looking for, what about the jap lumps they produced based on the old english bikes like trumps and bsa's? It's for a 1951 Sunbeam 500cc twin. Not the most common engine in the world, but I'm looking to get the original lump's 24 bhp up a bit, mid 30s would be cool. The W650 top end was a very good call, although seemingly quite rare. They are rated at 46bhp with 675cc, so bhp would be ballpark. Unfortunately the new Triumph twins have a central camchain, otherwise a DOHC injected setup was on the cards... Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 Where's the cam drive on the latter-day Laverda twins? Such as Alto racing used to campaign before the Vyrus? Eddy Central. Arse. Link to comment Share on other sites More sharing options...
kaighn80 Posted July 19, 2010 Report Share Posted July 19, 2010 what about my arse being central??? its a short thing again isnt it???? Link to comment Share on other sites More sharing options...
Mark/Foggy Posted July 19, 2010 Report Share Posted July 19, 2010 Where's the cam drive on the latter-day Laverda twins? Such as Alto racing used to campaign before the Vyrus? Eddy Mainly to be found in skips unless I'm very much mistaken Link to comment Share on other sites More sharing options...
Mark/Foggy Posted July 19, 2010 Report Share Posted July 19, 2010 It's for a 1951 Sunbeam 500cc twin. Not the most common engine in the world, but I'm looking to get the original lump's 24 bhp up a bit, mid 30s would be cool. The W650 top end was a very good call, although seemingly quite rare. They are rated at 46bhp with 675cc, so bhp would be ballpark. Unfortunately the new Triumph twins have a central camchain, otherwise a DOHC injected setup was on the cards... That's gonna have a long stroke and small bore, maybe some thing a bit smaller would do. XS400, CB400 Super Link to comment Share on other sites More sharing options...
Evilchicken0 Posted July 19, 2010 Report Share Posted July 19, 2010 What's wrong with the original - It might be an easier starting point than modifying a different head Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 That's gonna have a long stroke and small bore, maybe some thing a bit smaller would do. XS400, CB400 Super 70mm x 63.5mm Bore/Stroke. Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 What's wrong with the original - It might be an easier starting point than modifying a different head 24 bhp. It's also a poor design -it was meant to have a proper crossflow design and twin carbs, but budget cuts, and the test machines wearing out the shaft drive worm gear (which was due to using an oil which ate the material, but still) they decided to detune the engine spec. At that moment, crossflow heads and twin carbs were thrown out. There is a fair bit of work required to get the thing working properly (lubrication) and holding oil anyway, so I may as well make it right in the first place. I don't expect it to be fast, but how it should have been would be nice. I'll have the stock bits to return it should I choose. Link to comment Share on other sites More sharing options...
kaighn80 Posted July 19, 2010 Report Share Posted July 19, 2010 i have an early gsxr400 head without cams if thats anygood? Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 i have an early gsxr400 head without cams if thats anygood? Thanks for the offer...I think the bores will be too tightly spaced, but could you measure centre to centre of 2, just to make sure? Link to comment Share on other sites More sharing options...
gasman Posted July 19, 2010 Report Share Posted July 19, 2010 Which Sunbeam is it Fran - the S7 with the balloon tyres? If so it soesn't matter how many horses you've got your still gonna look cool as on and old girl like that! I've always liked the look of them but didn't realise they were so underpowered. IIRC you're not too far from me, any chance of a nosy some time when you've got things sorted? Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 Which Sunbeam is it Fran - the S7 with the balloon tyres? If so it soesn't matter how many horses you've got your still gonna look cool as on and old girl like that! I've always liked the look of them but didn't realise they were so underpowered. IIRC you're not too far from me, any chance of a nosy some time when you've got things sorted? This is all I have at the moment, and they are S8 bits -however, the frame is as the S7 bar the seat (haven't got either) and the addition of a side stand, but I intend to build it as an S7. I'm intending to make the bodywork, which is a bit of a challenge, and as the stock S7 forks cost as much as the bits so far, I'll be using a different set, made to look the same if you follow me. When I have something to show, your welcome to see it. I know where there is a stocker too... Link to comment Share on other sites More sharing options...
fran9r Posted July 19, 2010 Author Report Share Posted July 19, 2010 Oh, and I've joined the fellowship too. I though it would add an extra bit of interest if people see me on a gentleman's motorcycle, a fellowship member, as I loose my rag and yell GENT at them. Link to comment Share on other sites More sharing options...
lorenzo Posted July 19, 2010 Report Share Posted July 19, 2010 TRX850 twin? Watercooled and would look waaaay too modern in my opinion. I'd say you're going to get the most joy from 70's and 80's bikes of about 400 cc, and if the price on this stays the same, I'd ignore the fact that the chain's in the middle. Link to comment Share on other sites More sharing options...
fran9r Posted July 20, 2010 Author Report Share Posted July 20, 2010 i have an early gsxr400 head without cams if thats anygood? Someone has just pointed out the GSXR would also have been available with variable valve timing. Although completely out of place, for some reason I'm excited about that... If you could have an approximate measure up, it would be appreciated... Link to comment Share on other sites More sharing options...
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