Norton Commando 908cc Cafe Racer

billbell1960 · Jun 24, 2012

Following the demise of a 650cc engine in a featherbed frame, we're rebuilding the bike with a 908cc engine from Norvil, more info on my blog link below

http://nochangegiven.com/ncg/

Nellie_Rocks · Jun 24, 2012

Damn! A 908cc engine sounds like some serious fun.

Nells (formerly of Wolverhampton)

billbell1960 · Jun 24, 2012

Norvil reckon it's a 140mph machine, god knows if it will even tick over in traffic

Where are you now Nells? I'm up in Stafford

Nellie_Rocks said:
Damn! A 908cc engine sounds like some serious fun.

Nells (formerly of Wolverhampton)

Nellie_Rocks · Jun 24, 2012

Hey Bill:

I moved to the US of A, St. Helena, Napa Valley ~ Wine Country! Although Halfpenny Green Vineyard has everything beat ...

Enjoying riding the Norton with British pride, especially as it was 'born' in my old stomping ground.

Cheers,

Nells

billbell1960 · Jun 24, 2012

Hey Nells,

Sounds quiet brilliant, nice to think your riding a machine built around the corner from you in such a pleasant place. Thanks for dropping by, I plan to put some stuff about our ride outs around Shropshire on the site but so far this year it's been a wash out.

Bill

Nellie_Rocks said:
Hey Bill:

I moved to the US of A, St. Helena, Napa Valley ~ Wine Country! Although Halfpenny Green Vineyard has everything beat ...

Enjoying riding the Norton with British pride, especially as it was 'born' in my old stomping ground.

Cheers,

Nells

Foxy · Jun 25, 2012

billbell1960 said:
Following the demise of a 650cc engine in a featherbed frame, we're rebuilding the bike with a 908cc engine from Norvil, more info on my blog link below

http://nochangegiven.com/ncg/

Gday Bill and welcome!! Thanks for posting the link to your excellent blog! Im impressed with your build as Im currently (slowly) building a cafe except with 920cc ,90 deg offset crank with Jim Schmidt longer rods and pistons plus 35 mm Keihin flatslides to name some of the expense so far. Through the post is a slow way to get a bike but Im sure it will well worth the wait when finished! I will be looking at your bikes progress with great interest, good luck
Regards foxy

jseng1 · Jun 25, 2012

A large displacement Norton motor in a solid frame will gradually shake your brains out of your ears unless you have JS lightweight pistons.

Then there is the augment of whether on not shaking out the brains makes any difference - I'll leave that to others.

Jim

billbell1960 · Jun 25, 2012

Yep, should prove interesting Jim, might have to take the teeth out before opening her up.

jseng1 said:
A large displacement Norton motor in a solid frame will gradually shake your brains out of your ears unless you have JS lightweight pistons.

Then there is the augment of whether on not shaking out the brains makes any difference - I'll leave that to others.

Jim

Hobot · Jun 25, 2012

Standard crank BF in solid mounts is mid 80's to mid 90's percent. Lighter rods and pistons naturally rise it plus less jerk inertia. There is history of 360's solid mounts fracturing frames even if pilot can take it awhile. I hardly ever rode my solid 750 P!! over 70-80 where grips began to swell bigger than my hands felt they could grip, even as dumb-numb 21 yr old. P11's frames were made to take this and long term daily users adapted Honda rubber mount bars to stand it. I love the experimentalists as how else the rest of us gonna learn the easy way. Striking to view the build, so off to blotter my drool again.

speirmoor · Jun 25, 2012

Thats really nice cant wait to see it finished.Great pics too.Whats the reason the Amals are cocked up like that and whats does the copper line do?

Tintin · Jun 26, 2012

billbell1960 said:
... we're rebuilding the bike with a 908cc engine from Norvil,...

..and with a bolt-on hub plus a belt drive which will leave you without a cush drive. I did this too when I first restored my Atlas and consider it to be my major rookie f*ck up which killed the mainshaft pretty quickly.

Tim

billbell1960 · Jun 27, 2012

Tintin said:
billbell1960 said:

... we're rebuilding the bike with a 908cc engine from Norvil,...

Click to expand...

..and with a bolt-on hub plus a belt drive which will leave you without a cush drive. I did this too when I first restored my Atlas and consider it to be my major rookie f*ck up which killed the mainshaft pretty quickly.

Tim

Not in the plan to create something to self destruct, thanks for your point

billbell1960 · Jul 15, 2012

Some updates to the blog including a trip down to Brooklands for the Goldstar Owners Club weekend and a rebuild of a Norton Commando 908cc that started as a replacement for a blown engine and became a full on rebuild. Blog link is http://nochangegiven.com

Foxy · Jul 15, 2012

Thats the best blog ever IMHO. The pics are brilliant, thanks Bill!

Rohan · Jul 15, 2012

speirmoor said:
.Whats the reason the Amals are cocked up like that

Downdraft angle of the carbs is/was thought to be essential for good gas flow path into an engine. Be interesting to hear if these heads have been gas flowed to suit ??
(And what Comnoz says).

And if the carbs will satisfactorily carburate at that angle - Commando had the little curved manifolds to get the carbs back level - possibly at the expense of gas flow ??

Interesting project !

billbell1960 · Jul 15, 2012

Rohan said:
speirmoor said:

.Whats the reason the Amals are cocked up like that

Click to expand...

Downdraft angle of the carbs is/was thought to be essential for good gas flow path into an engine. Be interesting to hear if these heads have been gas flowed to suit ??
(And what Comnoz says).

And if the carbs will satisfactorily carburate at that angle - Commando had the little curved manifolds to get the carbs back level - possibly at the expense of gas flow ??

Interesting project !

Had the bike running earlier today, there's still some tuning to sort out, I'll try and edit some video together for you in the next couple of days

billbell1960 · Jul 16, 2012

Here's an pic of the ports, you'll see they have been reworked to address the gas flow, in addition the engine has been balanced for a featherbed frame.

mjfriesen · Jul 17, 2012

speirmoor said:
Whats the reason the Amals are cocked up like that and whats does the copper line do?

I think the question about the cocked up Amals has been answered, and I suspect the copper line is to provide an alternative oil drain from the head to replace the normal drain that was messed up when the inlet ports were re-worked.

Pretty cool work.

Hobot · Jul 17, 2012

Bill, pray tell how Amals modified for decent float level function? Only gasoline flow mod I know of is to open a slot into bowl just above the needle seat but below the needle itself so fuel flow not limited by all of it passing around the needle.

There ain't enough downward slope in this install to take much if any advantage of pure gravity to help mixture speed, mainly less an angle to turn in the already too sharp head port, which Bill has also lessened by modified ports and so the oil hole removed and replaced by external brittle prone copper drain.

Uplifting photo-blog Bill and should be a real grin widening and tire wearing de-lighter.

bwolfie · Jul 17, 2012

When you ride around in a constant wheelie, the carbs are level and there are no issues

Norton Commando 908cc Cafe Racer

Similar threads