143MPH 850 MK1 Commando?

Nortiboy · Jan 12, 2012

john robert bould said:
Bill Munro's Indian clocked 198 not bad for a bike that did 55!
.

Gooday JRB

Would that be Burt's brother?. Burt Munro's Indian was clocked 1 way at well over 200 mph but could not complete the necessary 2nd pass.

I have a magazine with a PR 750 track test officially clocked at 131mph so its not such a stretch to 143.

Carbonfibre · Jan 12, 2012

Rohan said:
Carbonfibre said:

143mph from a Commando?.................. To go that fast the bike would have needed at least 80bhp at the rear wheel, and or a very effective lay down streamliner type chassis.

Seems strange that myths like that get taken as fact over the years, even though its simply not possible for a bike to go that fast without far more power than it was likely to have had at the time of "testing"...................

Click to expand...

Speed was officially clocked at an International Speed Meet at Elvington.
Talk to them about the accuracy of their equipment ?
Eyewitness reports say that it was FAST.
A 24 t gearbox sprocket a shade over 7000 rpm would do about that, so it is feasible.
1/4 mile times weren't one offs, bike was often dragged.
Posted a pic here recently of 1974, already ahead of a Onda...

Did you see the photos.
Dave Rawlins is built like a jockey, and gets down to it.
Like all the best MotoGP jockeys these days, 5 ft nothing and 7 stone... (well almost)
Peter Williams was a foot too tall for a really faster racer ?
No disrespect, obviously was good at it, and knew what it was about.

P.S. Speed and event was quoted in the 1973 Norton Brochure, so there has been almost 40 years to disprove this claim....

Ok then............the 143mph must have had 80bhp+ at the rear wheel. Not impossible, but not sure a motor that highly tuned would have lasted very long if fitted into a road bike?

JimC · Jan 12, 2012

While I don't doubt official records, some of the undocumented top speed claims by Commando owners reminds me of when I was dating Sophia Loren and Raquel Welch. Only in my mind.

Rohan · Jan 12, 2012

Carbonfibre said:
Ok then............the 143mph must have had 80bhp+ at the rear wheel. Not impossible, but not sure a motor that highly tuned would have lasted very long if fitted into a road bike?

Commandos are quite slim bikes compared to Z1 porkers, you can probably subtract 5 hp from that , and make it bhp at the engine ?

The article posted elsewhere here on the same subject does mention they tried road racing this setup, but proved fragile. This is where Steve Maney stuff comes in - and what the factory should/would have done (if they'd had the funds )(and politics hadn't interefered ?).
If the new engines they kept having designed but not made had continued on the same path - Cosworth etc. I always wanted a 1000cc watercooled twin. I see Y*m*h* have released a 1200cc trail bike with parallel twin cylinder engine...

72Combat · Jan 12, 2012

Us Kiwis are quite good at getting underpowered bikes to go fast.... :roll:
They got 180 mph on a Vincent outside Christchurch....on gravel I think.....its all due to running Avons....
Burt could have saved a lot on dosh and just gone up the road....
Note: I'd never heard of Burt Monroe tll the movie came out.... :shock:

[video]http://www.youtube.com/watch?v=-XjoExOoDXU[/video]

1up3down · Jan 12, 2012

Carbonfibre wrote:
Ok then............the 143mph must have had 80bhp+ at the rear wheel. Not impossible, but not sure a motor that highly tuned would have lasted very long if fitted into a road bike?

Carbonfibre, As I don't have your extensive background in engine building, could you please show your math, how you arrived at your calculation that the motor in question had to have the 80hp at the rear wheel?

How did you calculate your 80hp figure?

As compared to say 70hp?

Thanks for showing us how you worked this all out, you are so knowledgable and so good to give your thoughts!

worntorn · Jan 12, 2012

JimC said:
While I don't doubt official records, some of the undocumented top speed claims by Commando owners reminds me of when I was dating Sophia Loren and Raquel Welch. Only in my mind.

Raquel Welch, for sure I believe that, but Im having real trouble with the Sophia Loren part. I read somewhere that she would only hang with Duc riders, too good for Nortons!

Glen

worntorn · Jan 12, 2012

72Combat said:
Us Kiwis are quite good at getting underpowered bikes to go fast.... :roll:
They got 180 mph on a Vincent outside Christchurch....on gravel I think.....its all due to running Avons....
Burt could have saved a lot on dosh and just gone up the road....
Note: I'd never heard of Burt Monroe tll the movie came out.... :shock:

[video]http://www.youtube.com/watch?v=-XjoExOoDXU[/video]

186 it was on the Tram road.

Saw a black and white movie reel of it, the sound and the speed was quite amazing.

Glen

ML · Jan 12, 2012

Carbonfibre said:
143mph from a Commando?.................. To go that fast the bike would have needed at least 80bhp at the rear wheel, and or a very effective lay down streamliner type chassis.

Seems strange that myths like that get taken as fact over the years, even though its simply not possible for a bike to go that fast without far more power than it was likely to have had at the time of "testing"...................

That's right THEY LIED, Motorcycle News lied, Dave Rawlins lied, Norton lied, Elvington Time Marshalls lied, even the photographs are lies its all lies isn't it Carbonfibre????

Oh - how about a little example of relevant fact? Rollie Free on a Vincent Black Ligtning - 1949 and he clocked 150MPH. Did it have 80HP? No, less than 60. Did it have a streamliner? No. Or did they lie as well?

You are not an engineer and do not understand science and again ignore and disbelieve facts from genuine and creditable sources. Your inanane remarks are a danger to novices to this forum who may unwittingly be misguided.

Mick

JimC · Jan 12, 2012

worntorn said:
JimC said:

While I don't doubt official records, some of the undocumented top speed claims by Commando owners reminds me of when I was dating Sophia Loren and Raquel Welch. Only in my mind.

Click to expand...

Raquel Welch, for sure I believe that, but Im having real trouble with the Sophia Loren part. I read somewhere that she would only hang with Duc riders, too good for Nortons!
Glen

Nothing says you can't own a Ducati and a Norton at the same time.

worntorn · Jan 12, 2012

Just to maintain some accuracy, Rollies' Lightning (owned by John Edgar at the time) was factory rated at anywhere from 75 to 85 hp, the range for lightnings, which were built to order with differing specs.

ML · Jan 12, 2012

worntorn said:
Just to maintain some accuracy, Rollies' Lightning (owned by John Edgar at the time) was factory rated at anywhere from 75 to 85 hp, the range for lightnings, which were built to order with differing specs.

Thats' interesting. According to Ian Harper in his archives with Paul Richardson and Ted Hampshire who built the 1st Lightning - which went to John Edgar for Free's speed attempt - the engine testing at Stevenage got a best reading average of around 65HP. However, there were several cam grinds and carburettor changes that had to be made in the US as Bonneville is 5,000ft above sea level. The BMEP at that atmosphere has a limiting influence. Those changes were never dynamometer measured. The gearing was raised to obtain the best inertia output hence it took miles to wind up to the maximum speed. Certainly from the Free record Vincent went on the publicise that as a "standard" specification motorcycle implying that was what a Black Shadow had. The next 28 Lightnings had any number of compression and cam options and in general, there never was a standard spec. But I can certainly understand that 75HP was achievable, but I doubt the Free machine got that much.

Mick

72Combat · Jan 12, 2012

JimC said:
worntorn said:

JimC said:

While I don't doubt official records, some of the undocumented top speed claims by Commando owners reminds me of when I was dating Sophia Loren and Raquel Welch. Only in my mind.

Click to expand...

Raquel Welch, for sure I believe that, but Im having real trouble with the Sophia Loren part. I read somewhere that she would only hang with Duc riders, too good for Nortons!
Glen

Click to expand...

Nothing says you can't own a Ducati and a Norton at the same time.

I like a pint of bitter when on the Norton...but a short black on the Duke...out of interest what is the BHP of a Combat as the Duke is supposed to be around 55BHP ( 80 HP , as opposed to BHP in the mags of the time)

Rohan · Jan 12, 2012

Nortons quoted 65 hp for the Combat.

It is not actually stipulated where or how they produced this number, but generally understood this was engine horsepower on a dyno, so would be bhp. Rear wheel horsepower would typically be less, around 50 for the Combat ?

Remember too that BMW was said to be the only manufacturer that quoted horsepower as a DIN number, which is said to be an engine tested with ALL the usual ancillaries fitted (air cleaners, alternators, std exhausts, etc) and not just the best flash reading, but a reading maintainable for some time. But at some point (mid 70s ?) they abandoned this practice, and quoted 'marketing' hp, like all the opposition...

worntorn · Jan 12, 2012

ML said:
worntorn said:

Just to maintain some accuracy, Rollies' Lightning (owned by John Edgar at the time) was factory rated at anywhere from 75 to 85 hp, the range for lightnings, which were built to order with differing specs.

Click to expand...

Thats' interesting. According to Ian Harper in his archives with Paul Richardson and Ted Hampshire who built the 1st Lightning - which went to John Edgar for Free's speed attempt - the engine testing at Stevenage got a best reading average of around 65HP. However, there were several cam grinds and carburettor changes that had to be made in the US as Bonneville is 5,000ft above sea level. The BMEP at that atmosphere has a limiting influence. Those changes were never dynamometer measured. The gearing was raised to obtain the best inertia output hence it took miles to wind up to the maximum speed. Certainly from the Free record Vincent went on the publicise that as a "standard" specification motorcycle implying that was what a Black Shadow had. The next 28 Lightnings had any number of compression and cam options and in general, there never was a standard spec. But I can certainly understand that 75HP was achievable, but I doubt the Free machine got that much.

Mick

Rollie Free ran the bike on alcohol fuel. I think it is likely that with everything that went into that motor and with the fuel, it was closer to 100 hp.
Steve Hamel has gone to great lengths to break Rollies record, and has done so, but done it on straight gasoline. He used a Standard 998 cc engine as base but did many mods incuding usingTerry Prince heads. He did some alterations to the Prince heads which resulted in additional power.
Steves bike can be seen on youtube making a 100 +rwhp dyno run, which got him about 155 mph.
I have heard since that Steve has made some changes and is now at 120rwhp, ready for Bonneville next year.

It will be ineresting to see what the result is.

I have a set of Terry Prince heads here, complete with the Steve Hamel mods that Terry now uses. These are going on a 1360cc engine.

Matt Spencer · Jan 12, 2012

Nortons ' Brake ' was a CRANKSHAFT unit , as is commonly known , all there rateings are recorded at the crankshaft .
( ANOTHER ADVANTAGE OF NOT GLUEING THE GEARBOX TO THE ENGINE :wink: )
the 155 mph ' Daytona ' machines were said , by some , to have ' Roadster ' engines .
If we ignore the ' Full Hemi ' type head , Thats About Right .pissy little carbs , too .

worntorn · Jan 12, 2012

Just to further confuse the issue, look at the speeds attained in countless races by the 50 hp Norton Manx!

How did they do so much with so little power?
A small light rider helps, I suppose.

Glen

Rohan · Jan 12, 2012

I've never seen anything of Commando engines on a dyno ?

What happened to the Dyno that Joe Craig had at Bracebridge Street ?
Did it survive the AMC takeover and then shift to Plumstead ??

Matt Spencer · Jan 12, 2012

worntorn said:
Just to maintain some accuracy, Rollies' Lightning (owned by John Edgar at the time) was factory rated at anywhere from 75 to 85 hp, the range for lightnings, which were built to order with differing specs.

The Bloke that Built the Burns / Wright Engine , under interegation (

:lol: ) suggested 90 hp was attainable before
catastrophic failure , with the standard ( Factory ) bottm end . ( Mainshafts / Bearings / rods ). Thats It .

He ragarded the Norvin ( Stock wideline , Red ( Red are generally faster , but more cantankerous :wink: ) ) as a 160 mph
capeability with that horsepower .

As he was the importer / agent / tuner & called and discussed the issues with Irvine whilst ' obtaining ' components for the
attempt , he was a bit caustic at any comment by wright as to ' Engine Building ' . As two weeks with no experiance of
the things was little time to do more than adjust the points . Particularly as quite some trouble had been taken to provide him with the equipment .( Basic train of comment was scoff , ha , balderdash , impossible . mutter mutter mutter ) .

Matt Spencer · Jan 12, 2012

Rohan said:
I've never seen anything of Commando engines on a dyno ?

What happened to the Dyno that Joe Craig had at Bracebridge Street ?
Did it survive the AMC takeover and then shift to Plumstead ??

They used to test them At Thruxton by hooking them up to a pump , That in turn was hooked up to the tanks in the Beer Cellars at the local Brewery . they knew by how many gallons of beer per hour they obtained , a fairly accurate output figure.

143MPH 850 MK1 Commando?

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