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Discussion Starter #1
Hi all
new member to all this, just want to show the newest build I've done.
It's based on the cafe racer theme. Nourish weslake 950 engine. 180 degree crank z profile cams with 14:1 comp ratio. To run on methanol.
Which turns a norton 4 speed ATM ( changing to a 5 speed modified to sit in a 4 speed housing.)
Placed in a featherbed frame. Still only in the early stages lots of things to change an modify after it's first run down a drag strip.
Cheers
 

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Okay, please educate me.
Whats a Nourish or a Weslake?
 

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Discussion Starter #7
My mistake. It's awesome that all these Nourish powered machines are coming out of the wood work!!!!

whats the history on this one?
Well I brought the engine about 10 month ago. He had got it specially built back in the late 80's
to go into a drag bike. Hence the high comp. it has over size pistons an values an Amal carbs already set up to run methanol. I got all the manuals, parts books am receipts from when it was ordered from dave nourish. But the project never happened. The engine sat in a create all sealed up for 25 years. I already had the featherbed frame laying around at home an a fair few bit an pieces to start the build. Still had to buy an make a lot of parts to complete the build. Still long way to go to get it the way I want. The engine was made to have a output of 100bhp on methanol. An after it's first major ran/ race, it has every bit of a 100bhp. Im thinking of dropping the compression to make it more user friendly. image.jpg image.jpg image.jpg image.jpg
 

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Okay, please educate me.
Whats a Nourish or a Weslake?
Jag read this first:
Weslake - Wikipedia, the free encyclopedia

an then this:
Any diff between a Weslake and a Noursh-Weslake? | The Competition Forum | BritBike Forum

And just to add to it: in addition to triumph heads, Nourish produced complete racing engines. They are kinda rare. Apparently they come up often enough in England but here in the US I don't know of any. I know hoof has a 500cc weslake single here but I think he brought that over himself.
 

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That looks like a great project Sean.

You may want to rethink the Norton gearbox though. I raced Commandos for many years and I can tell you the transmissions were the weakest link on them, as it was designed for a bike with around 40 hp originally if I remember correctly. That Nourish will have enough hp to destroy that gearbox if you aren't very careful.

I road raced with the stock gearbox but always set the clutch pack up "soft", meaning I used Barnette fiber friction plates but always included at least one stock bronze plate to build in some slippage. The only time I didn't include the stock plates it broke the mainshaft.
The housing is also easy to break.

The primary chains were also short lived and I had to change them between races at the track due to them kinking up. That was using the stock triplex chain.

I have friend who builds race Nortons and he uses a Triumph right-side shift gearbox from a Bonneville, he saws if off the engine and uses the Triumph clutch and belt drive primary. He is a machinist though and has the equipment to make the necessary parts for the conversion.

Good luck with the build. I will be interested to see it completed.
 

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Discussion Starter #13
Cheers norton357,
Yes I am change the norton gearbox out. I fitting a triumph 5speed unit cluster into a pre unit casing. A little bit of modify will have to done I'm told, but doable. From what I've read an spoken to people about it. It should be good combination. I think I might look into changing to belt drive in that case. I've only had one test run so for an it burn the commando clutch an the gear shifting wasn't user friendly.
 

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Sean, I`ve put a T140 5 speed cluster into my old pre-unit gearbox casing. Its relatively straightforward and you can also fit the later needle roller bearings. Dave Nourish made 3 different length Mainshafts specifically for this and they take a Norton splined clutch. The longest option is if you want to fit an outrigger bearing, which helps take stress from the outer gearbox bearing and mainshaft.

Nourish also used to have a heavy duty gearbox casing available, but he packed in with those when TT industries started selling theirs. I saw one on his bench while I was down there, but he wouldnt part with it.

You can still buy the mainshafts from Nourish Engineering. I put all new internals in mine, but they needed polishing to work nice and smooth.
 

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Discussion Starter #16
Thanks for the information on the gearbox mark. That will come in handy for sure. Ill definietly look into getting that mainshaft to suit the norton clutch, plus the outriggger set up.
 

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Hi Sean

A nice find but what are you going to use the bike for? I guess you know the bike will ride like a camel unless you very good with the throttle otherwise 14:1 and methanol will be a snatchy as hell. Also the engine will run cooler than petrol which isn't a problem if you are going to nail it everywhere (whilst looking skywards) but for average road use the bike will struggle to get to temperature giving piston clearance problems and cold seizures. I guess you've seen methanol engines with fins cut off etc so they are not over cooled.

Ref transmissions; With a 950cc and 100hp of fire breathing monster you don't need 5 gears, you'll be lucky to hook into 3rd before blue flashing lights appear. The triumph pre unit box is easy to convert to later step shaft unit 4 speed, push out the layshaft bushes and fit the later Torrington needles which will go straight in. Everything else is straight forward build but you must use the later unit layshaft if you refit the preunit cluster. As no one has mentioned it, the standard 4 speed triumph box is quite a good unit, those wider gears can take a lot of load. 5 speeders have narrower gears and therefore weaker but have better dogs. Unless you are going racing and have deep pockets go 4 speed its a fraction of the cost. That said I used a 5 speed P&M box in a 998cc 97hp Rocket 3 and it never gave a minutes trouble but the cluster did cost my left nut. Nothing wrong converting to standard 5 speed as stated above it an easy convert too.

If you go down the AMC route, the box Achilles heal being the mainshaft sleeve gear bearing spinning in the case as the case cracks between the mainshaft and layshaft bearing housing. Also a common failure are the layshaft bearings collapsing. But again I would stick to 4 speeds and note Quaife do a heavy duty casing. The TT industries drum selector 5 speed box is great and beefier everywhere but £3k ish.


Reference the out rigged bearing, Nourish copied this from Gary Bryan and John Rea of RGB Weslake fame. But hey the engine was Harry Weslakes! If you can't afford the splined mainshaft the standard tapper is ok but USE A NEW WOODRUFF KEY, ENSURE THE GEARBOX TAPER AND CLUTCH CENTRE ARE UNMARKED AND LAP THEM IN WITH FINE GRINDING PASTE. If you do this and torque up correctly to 60lbs with a new nut you will not have a problem until you try to get the centre off (you will need the standard puller and a little heat). Most who have problems don't fit the centre correctly.

Finally fit a cush somewhere in the final drive, a belt helps but its not enough. But if you are just going to pootle about then you should be ok without but I would not risk it. Worth mentioning that in period c1970 when the twin turned up most used Norton 3 spring clutches which have a cush centre. Or a rear wheel cush.

All from experience, I have built some chunky twin engines over the years with over 140mph on tap and they don't blow up.

Enough from me, good luck with it.
 

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Discussion Starter #19
Thanks for the info jalsteve, has given me a lot think about an consider. I have thought about dropping the compression back so I can use premium fuel instead. I do want to use it mainly as a road racer. So there is a few changes I need an want to do.
 

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If you want to go road racing you'll need to start over.

1st you going to find out the brake isn't going to stop you, with a race brake your forks will not be up to it, you frame which is mid 50's will struggle with 100hp, and the engine will turn you drive train in to land fill. The frame will crack in the usual place above the gusset place drive side and so on......

I guess you will race it in post classic 1963 to 72 (period 4) so discs are the way to go, forks can be up to 38mm. Move the engine forward in the frame a bit, belt drive like NEB or a Norvil item it a must so is a rear wheel cush drive. You have a good motor put it back on petrol, in Europe Methanol is banned in classic bike racing but I think your ok in group 4 but not in group 5 or 6 in Aus.

Lots to do.
 
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