Big single engine - advice wanted

Yep, it's mine !!!!!!!!!!!!!!!!!!!

Had to go to $120, but he threw in the carbs for that.

So it looks like "Project Single" is all ready to go next year with the TT600 Belgarda powerplant.

Now if only I can get a GT750 brake / front wheel for $100 .................................

SDC10289vv.jpg
 
god thats a big single!

if the tanks longer then 22 inches, i suppose i can cut it down if its glass or alloy. 22 inches is right around the mark for what i need. dont rush yourself on the tank, no time constraint really :D


mmm, this project is going to sexy!
 
Guess you're right Tim - only one GT750 brake on UK E-Bay and that's starting at $400!

And there's folk from US, Italy and all over interested.

Still think my best bet will be the Classic Bike shows - stuff generally goes cheaper there.
 
Juggernaut said:
How is that engine a single cylinder when I think I see two intakes?
Click to expand...

a bunch of large singles have dual intake ports/exhausts.
 
Spot on Rocan.........

Juggernaut when single cylinder engines went "big", to have an single inlet and exhaust valve large enough to be efficient.......er, wasn't. They were too big and heavy to move quickly and nowhere near as efficient as the coming technique of 4 valves [ or 5 ] per cylinder.

Don't forget, in our day a "big" single was 500cc !! And they were generally restricted to 6000 rpm before things started self destructing. Just ask Hoof about his Inter Norton !!

There were a couple of oddball 600cc singles - The P&M Panther [ mainly for sidecar work ] and I think [ help me out here Hoof ] an old Norton - maybe sidevalve?

So, when the big singles needed to get more efficient they went to 2 inlet and 2 exhaust valves. To continue with the efficiency theme, it then made sense to have two seperate ports for each - and thus two carbs - two exhausts.

I'm toying with the idea of using a single sidedraught Weber DCOE carb - just for the hell of it.

Somehow I need to siamese the exhaust very close to the head so I can get a Gold Star type single swept back exhaust.
 
Panther went out to 650 with the model 120.
My brother has the one our father willed him (another brother has 1928 BSA 'Sloper' twin port single)
Twin exhaust ports with single valve was a throwback to the 1920's
I may not be as old as you and Hoof but this is pretty much all I've done for 40+ yrs.
Should have got a proper job instead of playing with motorbikes ;D
PJ
 
Speaking of which; What about an Ejnfield AVL or even a new UCE lump?
The new ones come with or without kick-start lever, but both have a reliable E-start now.

Ask Hitchcock's.
 
Thanx for the correction Crazy - the old memory's getting a bit feeble now !

I was given a pre-war BSA split port single [ nothing new under the sun eh?] when I was 15 or 16. I'd just got into Sprinting [ similar to Drag Racing but against the clock ] and had built a MAC Velo on methanol. I befriended a local girl who'd just become a trainee nurse - not the prettiest piece , but she had access to free methanol !!

Being somewhat green in thermo mechanics we decided to try and run the Sloper on Methanol.................. It's a good job it was Sloper as when the head eventually decided to part company with the barrels - it was pointing away from the future of the Beachcomber children.

Rocan, here's another pic to give you some idea. The tank is actually 24" long - slightly less [ 23" ] where the tunnel is.

Looks easy to shorten from the back if you had to.
I have all the relevant dimensions - if you want to PM me with a contact I'll send the file direct to you.

Note all the snow gone - we had a massive thaw in the past 4 days - floods everywhere now, but heavy snow predicted again for next week.

SONAVON003.jpg

SONAVON001.jpg
 
beachcomber said:
Note all the snow gone - we had a massive thaw in the past 4 days - floods everywhere now, but heavy snow predicted again for next week.
Click to expand...

I hear you! Been busy getting in haylege, feed, firewood and tins of soup ready for the next tump load.
The snow from the north east is manageable but we got a second wave from the west which is just wet shitty stuff.
Combined with - 13, that's when our problems really started. The wind chill killed the battery in my truck so now $120 lighter. >:(
 
Cool, we had a 350 MAC given to us when I was about 13~14
Dowty 'Oileomatic' forks on it.
No springs, just air pressure.
Needed pumping up every day, sometimes twice a day :D
After we got everything fixed, guy ended up wanting it back (his mother shouldn't have given it away ::))
 
Speaking of big singles in XS500 chassis's, in 2007 I put a fresh CR500 hotrodded 2 stroke in my spare chassis.It was a beast, but man that thing shook everything loose.I got tired of kick starting that monster. :D
 
OK - that's plan "A" out the window then - futtox.

I could NOT believe that the TT600 Yam engine would NOT fit in the XS500 chassis.....................well to save anyone else the grief - it doesn't! Not without hacking the frame about and that's not what I want to do. I've asked elsewhere for the dimensions of the Savage [ LS650 ] lump, as from a purely aesthetic viewpoint - that's the one. The barrels / head/exhaust already have that Goldie 'ish look and with the "cruiser" chrome top covers naffed off - looks very purposeful.

There's always a possibility that the Savage engine is too big enough - but that's the next plan. Worst case scenario would be to use the complete Savage and revamp the frame / headstock angle to be more CR like. Also ditch the belt drive for a chain [ aesthetics again ].

Unfortunately that still leaves me with the single front downtube - and I'm loving the style of the XS500 frame - very AJS 7R / Goldie 'ish.

Thanx all for the headsup on alternates [ just love this forum ] - I'll look at the Honda XR600 lump - at least if it has electric leg.
 
Reading this, i was expecting a DR800 BIG engine to be fitted... Although 650 isnt bad ofc ;)
Very curious on the parts you are going to use and the looks.
 
Nomad,

I'll get some mockups done once I have the Savage engine dimensions. Pointless going any further until I've got a fighting chance of putting it in the XS500 chassis.

Looks ? Imagine something like Tim's XS650 but with a big single in it.

Re: the DR Big - speed / performance isn't the issue here [ otherwise I'd build a CB750] - it's the looks I want. Naturally I'd like whatever I use to be better than stock.
 
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