Maney Stage 1 Head?
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Rohan said:
I posed your question to to the shop that did the dyno work. Here is there response.
Hello Bill,
I don't know if there was a software glitch or what, but I went back and brought up those two runs and they crossed on the new computer at approximately 5250 rpm. I was not aware of the need for the curves to cross at that rpm. The values are the same. I guess you get to learn something new every day, given the opportunity.
If you would like, I can see about having Fred email them to you.
Cheers!
Bill
I will post new graphs when I get them.
Bill G
acotrel said:
Thats a somewhat hypocritical troll comment ?
You have, as a highly modified Commando, a now looking-as-a-Seeley racer, with a near near stock 850 engine. As you keep telling us.
Running on methanol, no less ! As you keep telling us.
Intended for racing, but rarely ridden ? As you keep telling us.
And someone here wants to tweak a stock bike for better road performance.
And the factory even issued bulletins on how owners could achieve this themselves.
Bikes have always been tweaked and modified, its part of the scene.
If folks thought they couln't build a better mousetrap, we'd all still be riding penny farthings. ?
Hypocritical comments, indeed....
P.S. The reason that torque and hp curves usually cross at 5252 rpm is that at that precise rpm, because of the formula,
the torque value number, in ft/lbs is EQUAL to the horsepower number in hp.
So if the torque reading at 5252 rpm is say 54 ft/lbs, then the horsepower at 5252 rpm is 54 hp.
Or a car engine torque is say 450 ft/lbs at 5252 rpm, then the hp is 450 hp.
No calculations required.
But ONLY at 5252 rpm....
the torque value number, in ft/lbs is EQUAL to the horsepower number in hp.
So if the torque reading at 5252 rpm is say 54 ft/lbs, then the horsepower at 5252 rpm is 54 hp.
Or a car engine torque is say 450 ft/lbs at 5252 rpm, then the hp is 450 hp.
No calculations required.
But ONLY at 5252 rpm....
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acotrel said:
The "competition" is against boredom, the laws of gravity & physics A$$HAT!
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Would you have a link to that data?Rohan said:
I've done some port work in the past & think I could handle the job.
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A$$HAT! It does have a ring to it. :lol:
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Excuse me? I'm not the one criticizing others just because they want to do something different than what I would do..Snorton74 said:
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[/quote]
Would you have a link to that data?
I've done some port work in the past & think I could handle the job.[/quote]
http://commando.yolasite.com/performance-mods.php
the-story-the-fastest-norton-t12095.html
Would you have a link to that data?
I've done some port work in the past & think I could handle the job.[/quote]
http://commando.yolasite.com/performance-mods.php
the-story-the-fastest-norton-t12095.html
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Was info / write up , in This Magazine .( not this issue ) maybe someones got it ?? or knows issue ?
also I belive a more comprehensive write up / ups , in This Mag .
And Murry had a copy . He likely threw it out , as he did with a folder of road test reports .
also I belive a more comprehensive write up / ups , in This Mag .
And Murry had a copy . He likely threw it out , as he did with a folder of road test reports .
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Matt posted the head mod graphics that can be found in a number of manuals, Clymers to Dunstall Notes and the NOC Tech manual. Oh Yeah do not miss out on Jim's Schmidts Norton Race Manual with head to crank mods and Everything In-Between that's metalic to electric. Ya should have hard copy factory manual and the parts number book book fit in loose leaf binder. Most of what is disscussed here is new age options but if ya want the low down on working up and with factory parts [w/o the bickering] spend a year while waiting on cash pull up Capt. Norton.
One thing for sure is Norton are severely allergic to hi rpm and 89mm stroke with 850 jugs tends to top out friction wise about 7000 normal red line or less, so the hi rpm flow like racers sustain ain't what works best in real life twisties, hell even the racer boys spread out 1/10 mile all pile up at first real turn to start the race all over again. Big-ish inductor funneled down to smallish ports and mildly bigger valves with some exhaust tuning of 1.5" pipes should impress ya w/o breaking the bank.
There is controversy on dual or single carbs but there's at least two of us here that swear by a single bigger carb. One fella was so so pleased with a single 38 mm on his 850 only a few of us believed him. One trick that shocked this snot out of me after finding out in my driveway that I was not man enough to keep off tail lens on throttle snaps by just arm grip, by creating a flow trip lip/step at the head surface, in other words I did not funnel the junction smoothly though same effect can be gotten by DIY gasket that slightly intrudes at the bottom area.
I alert you that an un-tamed isolastic Commbando handly and quick as they are, at some point/conditions they turn into one of the most dangerous cycles of all time with weave/wobble = fish flopping off the deck Hinging. Ain't no way it can handle like your Harley beast allowed. No Sir Red Bob! Nor trying to match a decent sports bike rider. You may be able to follow em into turns and sweepers but about half way though if road not perfect and banked and wind gusts about you may wish you never got on it, if ya live. This means going over twice the posted speed of the 35 and above marked turns and at least 45' lean. What a sports bike may take at 90 may get the un-tamed Cdo at 80. Most the Cdo fun is in the 35-90 range in 2nd then the long legged 4th pull rather over 125 if hot rodded a bit as outlined.
One thing for sure is Norton are severely allergic to hi rpm and 89mm stroke with 850 jugs tends to top out friction wise about 7000 normal red line or less, so the hi rpm flow like racers sustain ain't what works best in real life twisties, hell even the racer boys spread out 1/10 mile all pile up at first real turn to start the race all over again. Big-ish inductor funneled down to smallish ports and mildly bigger valves with some exhaust tuning of 1.5" pipes should impress ya w/o breaking the bank.
There is controversy on dual or single carbs but there's at least two of us here that swear by a single bigger carb. One fella was so so pleased with a single 38 mm on his 850 only a few of us believed him. One trick that shocked this snot out of me after finding out in my driveway that I was not man enough to keep off tail lens on throttle snaps by just arm grip, by creating a flow trip lip/step at the head surface, in other words I did not funnel the junction smoothly though same effect can be gotten by DIY gasket that slightly intrudes at the bottom area.
I alert you that an un-tamed isolastic Commbando handly and quick as they are, at some point/conditions they turn into one of the most dangerous cycles of all time with weave/wobble = fish flopping off the deck Hinging. Ain't no way it can handle like your Harley beast allowed. No Sir Red Bob! Nor trying to match a decent sports bike rider. You may be able to follow em into turns and sweepers but about half way though if road not perfect and banked and wind gusts about you may wish you never got on it, if ya live. This means going over twice the posted speed of the 35 and above marked turns and at least 45' lean. What a sports bike may take at 90 may get the un-tamed Cdo at 80. Most the Cdo fun is in the 35-90 range in 2nd then the long legged 4th pull rather over 125 if hot rodded a bit as outlined.
Matt Spencer said:
I have the Motorcycle Mechanics issue, but unfortunately can't find it. (have a few magazines, stored all over the place...)
It was 1974 - I think - would recognise the cover photo.
Tuning Sheets #1 and #2 are online - somewhere. Service Release N3/29 and N3/64
They are 4 pages each, those are just the diagrams that went with all the text.
i have a very low res print of a scan, but its barely readable.
Have a better copy too, but haven't seen it in decades.
I believe these are included with the Norton Commando CD that is a goldmine of all Commando stuff.
I have an early copy of that, but the tuning sheets were not included on early cds.
You have to be a pretty slow rider to never use ALL the performance.
Even if its just now and then, on a very rare basis.
(full throttle for MAXIMUM acceleration = not necessarily top speed - quite different things)
This is it - July 1974 - Champion Commando
This website looks like it says they have it in stock, for those in the UK ??
http://www.pigfarmerbikemagazines.co.uk ... ker_3.html
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hobot said:
I've been around long enough & had enough close calls to know that before you make a bike (or car) go fast, you have to do as much as practicable to make it handle & stop.
Engine power upgrades would be the LAST item on the list. Upgrades to the transmission, primary drive, brakes & suspension as well as electrics would have to be sorted out before even thinking about making more power. Safety & reliability are priorities before power.
Since I’m the OP on this thread & the end result is to end up W/a Commando that has better acceleration, (not all out top speed for you “hand wringers”) which would lead to higher speed coming into situations that would require optimal (within limitations) braking & cornering, I will now hijack the conversation to those ends.
What needs to be done to the Isolastic suspension to “tame” it?
I’m more than a little disconcerted that a Commando would not be up to the handling capabilities of my pseudo café racer Panhead hot rod. After all, even though I modified the chassis for adequate handling/braking to preserve my hide, it wasn’t what I would consider a real top notch handling bike.
Short of ditching the entire stock MK-II brake system, what can be done to upgrade it W/the stock caliper/disc?
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ludwig said:
And more cowbell!
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Rohan said:
Ed Zachary!
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Hobot, riding on the dirt is different to riding on bitumen. On dirt there is always a balance to be maintained between slide and drive. What internal gearbox ratios suit a road race bike, would probably induce wheel spin everywhere with a dirt bike. On my road racer, I run extremely high gearing with a close ratio box. In races where there is a clutch start, you can choose where you want to lose a race - at the start, or at the ends of the straights. If the bike is geared to use all the commando engine's torque, it will be difficult to get off the start line unless you run a low ratio first gear. With a dirt bike, the low first would mean you wouldn't get drive off the start line unless you fitted appropriate tyres which would then be useless everywhere else. I know I'm talking about racing, and you have the advantage that probably every drag you get into involves a rolling start,however the problems are still there. I found gearing my Seeley very deceptive. It appears to be delivering it's maximum urge, yet if you up the gearing by dropping a tooth on the rear sprocket it just seems to get quicker every time. If you don't ever really load the motor, you don't find out its potential? Perhaps an unloaded commando motor will only spin up at a certain rate?
This begs the question about what top gear ratio an otherwise unmodified commando 850 will pull and still accelerate at a fair rate,
This begs the question about what top gear ratio an otherwise unmodified commando 850 will pull and still accelerate at a fair rate,
SteveA
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acotrel said:
If you read the article that is linked out from this thread you will see a demonstration of an overgeared Commando, albeit a modified one, that had a 24 tooth gearbox sprocket in place of the standard 21, (22 on a MkIII) with a standard 42 rear and standard triplex primary ratio of 2.192:1....lets also assume all of teh followig considers a 19" 4.10 tyre...
The article notes significant reduced top speed into a headwind....
Seaching this forum for an answer Full Auto has this to say....
22 tooth was standard for the MK3. 21 for the 850s pre MK3. 23 tooth is maximum practical without engine mods and 3500 revs is 70mph.
What any of this means to you or me with 18" tyres of varying sizes and high ratio primaries and modified engines is somewhat moot...
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