what engine would you spec for my project (2014)

To max out on what available today plus all the special processing and treatments takes ~15 grand usd plus another 6-7 grand for a drive train - primary to gear box to take it. On the other hand there some famous records set with good ole basic Norton kit. There's been plenty of wild specials that got started with just an emblem to fit a cycle too.

Have you ridden many standard(ish) Commandos?

Fast Eddie said:

Micky,

You must build a1007 Maney engine.

And use lightweight pistons, similar to JS ones, but with a raised outer edge to maintain squish band whilst having a sensible CR.

A cam designed for lightweight radiused lifters.

A Fullauto head with a full Comstock head job on it inc oversized inlet valves.

Maney belt drive coupled to TTI gearbox.

Tri-Spark ign, FCR carbs (or Jims FI)

Then add half of the CNW parts list, just cos it would be rude not too.

Same attention to the chassis with upgraded brakes, Maxton suspension, etc, etc.

Its SUCH fun spending someone else's dosh!!

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For the raised squish pistons mentioned above. There was a time when I was too busy to design large bore pistons with a dished center. But I can do it now. The JS 1007cc lightweight pistons weigh in at only 240 grams. The motor you want has already been built and won all its races. After a season it was torn down by its builder Gordon Humphreys and it showed no measurable wear on the bore, cam etc. Gordon Humphrys is in the UK if you want to contact him for more info. See the 1007cc racer at the top of the web page below.

http://www.jsmotorsport.com/images.asp

The flat top pistons below will need a dish in to crown or a thick head gasket to bring down compression to street level.


Longer lightweight JS Carrillo rod below

Sir Jimmy sold me on those NASCAR grade gems, so what crankshaft would they like best?

hobot said:

Sir Jimmy sold me on those NASCAR grade gems, so what crankshaft would they like best?

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In the US my favorite crank is made by Greg Blagus at Rody.

I got a few from him but they are hard to get.

his email is

rodycranks@att.net
good luck - say Hi to him for me and tell me if/when you get a crank from him.

Yummy sights Jimmy, is anyone keeping track [besides me] of the invoicing to acquire best there is so far?

i've seen your site Jim, i've started to strip the old girl down over xmas.

barrels are cracked, but considering my options on using bottom end, that'll dictate cc's i guess. if i'm using all the commando bits then a 750 will do.

so could you guys help on a decent spec'd 750 motor please??? i'm thinking

maney barrels,
js pistons, rods, valve train parts
what else,larger valves
cam?
carbs
what mods can the standard cases / crank take to get them oil tight and go for more of a tune?

and then spend the money on a gearbox kit, i see quaife do a 6 speed kit for a norton now.

To go hog wild adds like 20+ lb with HD cases and tranny which need's like 5-6 hp/trq extra to make up for it or spending even more on 'cheap' mass loss items/processes. Hog wild power plants don't make much extra power till spun up to need special hi rpm items. Even bone stock engines can take 150 hp 8000 rpm if built well. Study TC Dragonslayer for proof and a bunch of track and desert racers too though not on nitromethane. A really ligthened up Cdo and Combat spec engine could breaking into upper 11 sec 1/4 m and hit 130 about anywhere ya care. State you most outrageous money limits to spare to get idea how bad a bike you might afford.

micky1 said:

i've seen your site Jim, i've started to strip the old girl down over xmas.

barrels are cracked, but considering my options on using bottom end, that'll dictate cc's i guess. if i'm using all the commando bits then a 750 will do.

so could you guys help on a decent spec'd 750 motor please??? i'm thinking

maney barrels,
js pistons, rods, valve train parts
what else,larger valves
cam?
carbs
what mods can the standard cases / crank take to get them oil tight and go for more of a tune?

and then spend the money on a gearbox kit, i see quaife do a 6 speed kit for a norton now.

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Your parts list above is good and will give you a reliable high performance motor. I suggest the JS1 cam kit for best all around performance but I would leave big valves as the last item and a lower priority. Much better to concentrate on good porting. For porting and crank mods get the JS race manual and follow the port specs for hot street or send it off and have it done. Also get the crank PTO shaft radiused according to the race manual specs if possible (see photo below) because this is the weakest point of the crank - but once done and using the lightweight pistons you will have no worries. For oil tightness use Yamabond or "the right stuff" and install a one way case breather such as the easy to plumb up Yamaha 650 valve from Mikes XS or spend more money and install the bolt up kit (requires machining and plugging of some timing chest vents - search this forum for crank breather etc). Carbs are multiple choices from the Amals to the PWKs (must be modified for Nortons) to the FCR or CRS Keihins all of which are searchable on this forum. but I would suggest staying close to 32mm. Look at the RGM peashooter mufflers with 1-1/2 ID for free breathing.
I would stick with a 5 speed as the 6 speeds are a little fragile with their narrow gears.

Hi Micky, What's your technical background like? Do you do your own spannering? Can you do this stuff yourself or will you be paying someone else to do it? 60% of Commandos went to the USA that's about 45,000 bikes. That's where the development has been done, most of it on this website. Good luck

hobot said:

Kenny Cummings a winning Commando powered Seeley racer has NYC shop/service to build you any engine maxed out as ya like so don't have to experiment developing your own and can get on with your own one in a row plans.
Btw the green thingy was offered a few times for sale at ~45,000 usd. Likely at some loss on the investment of course.

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I think JIm Comstock has something to do with Kenny's engines but I might be wrong.

gjr said:

Kind of makes me wonder how much Norton content it takes to make a bike a Norton ? Is the 'soul' of a Norton the frame numbers ?

Greg

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I know this thread is dead...but your question is still a valid one...
I believe in "atomic osmosis" and the connectedness of all things. The Norton-ness is stored in any remaining Norton part (no matter how small), and then flows under atomic osmosis to the new component..
The new component thus becomes Nortonized, and is capable of Nortonizing any other component that comes into contact with it.
Like a good axe, that's had 3 new heads, and 10 new handles...it's still the same axe..

So, what became of this?

Did he buy that HD at the end?

Function dictates format. If you want performance, light weight might be cheaper to get than horsepower.