155 HP 920cc Norton on Nitros - crash at Bonneville

Re: 140 HP 920cc Norton on Nitros

Running a bike at speedweek is not good - the track gets torn apart by the powerful cars in one or two days. I had to learn this when riding Max Lambky´s Vincent streamliner. I always tried to run on the outer edge of the course to avoid the deepest ruts but sometimes you get sidewinds that blows you into the ruts and you get all sorts of problems such as bump steering. As speedweek is the biggest event you have to wait for several hours in line until its your time on the track. So from 2005 on we opted for the BUB meet - the track is different to speedweek, very good prepared and much less time spent waiting at the startline. If everything goes well and you don´t need more than the usual maintenance on the bike you could get 4 to 6 runs per day - not possible at speedweek. Now lets keep fingers crossed that my ride (the Lambky liner) and the weathergods are in good mood at this years BUB meet and I set a proper record with these 60 years old motors - watch out for # 785 !

Re: 140 HP 920cc Norton on Nitros

I have to ask, doesn't this seem like excessive drive train loss?? 36hp, from 140 engine to 104 rear wheel? I've never seen that level of loss from a motorcycle.

Fred is hurt but he'll heal. Seems very irresponsible on the part of the organizers that the track should be so bad that you can't stay on the bike - putting someone at such risk at high speeds, not to mention the expense, the pain endured and being robbed of a speed record.

Fred's bike had another dyno run after I posted this discussion and I am editing to make corrections. It actually put out over 155 HP at the crank and over 107 at the rear wheel and yes that seems like too much friction loss but I don't have more details. I only provided some of the lightweight internals and assembly advice. This has got to be one of the most powerful Nortons ever and I was worried about the motor staying together - but it held up fine. Fred is a great rider and friend and I'm sad things went wrong. It reminds me of a Willow springs race when the 40mph gusts blew me off the track where I hit a pothole that bent both rims and sent me over the handle bars at 90mph - not a fun ride.

Below is a letter I got from Jim Mosher who poured so many hours into building the motor.

"Hi Jim, Jim Mosher here. Fred fell at 135MPH shifting into 5th. I haven't gotten to speak to him since he fell, because he was flown to the hospital, and then his brother took him home. He won't answer his phone. He broke 3 ribs, and dislocated his shoulder. The bike is pretty bad off, but the motor was very strong! On a soft run below red-line it made 107.4 rear wheel HP, and 155.9 at the crank! We would have gotten a record if he hadn't bailed."

jseng1 said:

Fred is hurt but he'll heal.

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Speedy recovery!

It actually put out over 155 HP at the crank and over 107 at the rear wheel and yes that seems a bit too much friction loss ...

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Actually it would be a world record in friction loss. By far.



Tim

Re: 140 HP 920cc Norton on Nitros

hobot said:

Gosh this racing is a tough man's sport in so many ways. Ken assured me a C'do based chassis is up to about any speed but any bike can meat its match on bad surfaces, especially the kind with a loose layer... Ken has another sad tail about a wining C'do that got into rough salt and died. Did he see blue/white blue/white blue/white or just white on white till stopped?

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Steve, this isn't a Commando chassis. It's a Seeley replica by the late John Caffrey. No isolastics here.

Ken

Re: 140 HP 920cc Norton on Nitros

Carbonfibre said:

Thats a real shame...............wonder what class he was running in?

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1000 APF. 1000 cc, special construction, unstreamlined, pushrod, fuel. Last year he ran 155 mph with it, right at the class record, and he was hoping to bump that up to a new record this year.

Ken

Re: 140 HP 920cc Norton on Nitros

1000 APF. 1000 cc, special construction, unstreamlined, pushrod, fuel. Last year he ran 155 mph with it, right at the class record, and he was hoping to bump that up to a new record this year.

Ken[/quote]


He beat all the HDs then? ................has to be a good thing!

Yep. Current record is 155.722 mph by a Harley. Fred ran exactly the same time last year. It would be nice to see some more Norton records in the books. As far as I know there's only one SCTA Bonneville record still held by a Norton twin. That's the 148.981 mph record set in 1999 by J. Smith on his turbocharged 850 Commando in the 1000 MPS-PBG class. That's the modified, partially streamlined, pushrod, blown, gas class. He's the one who died a couple years later at El Mirage when he made a run after the meet was over and the course markers were gone. He hit a rough patch and crashed.

There are some records by Norton twins in the AMA books from the BUB meets at Bonneville, but nothing very impressive. There is a 750 P-PP class record by a Norton at 120.914 mph. That's the 750 Production frame, production engine, pushrod class. There's also an embarassing 87.078 mph record in the 1000 S-PG class, set by my friend Eric in our 920 powered streamliner. Long story there. We've since dismantled the liner and are building an unstreamlined bike with the parts from it.

Ken

I just received this email from Jim Mosher:


Hi John, Jim Mosher here. Yes, Fred had a bad "off" on his Norton. The salt was rough, and Fred had a wild ride on his first run, so we went to another coarse, where they said the salt was better. He lost it going into 5th at 135 MPH, but evedince shows a blow-out of the rear tire. Fred's really shook-up, and the bike is a mess. I offered to fix the bike if he wants to do it again. He'll let me know later. He said the motor was alot stronger, and it is capable of the record. Oh well! See Ya; Jim Mosher."

Steve, this isn't a Commando chassis. It's a Seeley replica by the late John Caffrey. No isolastics here. Ken

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Oh, ok, a Sealy rigid with modern front. Mystery what happened. Tire shouldn't of been stressed at 135 yet If he'd done 155 prior w/o issue then suspect a part failure I guess. An endo at 135 could smash down a tire patch to split it I'd think.
What a hi side to brag surviving!

These harsh get offs take some time to fully develop beyond the local smacks and cracks, hope Fred does shake it off. I suffer a tad of post traumatic flash backs that makes me cry out cringe involuntary to jerk me out of edge of falling asleep - fine details of pavement in face exploding idust and neurons sparkles, or fine details of fur pattern on deer chest displaced by headlight rim that become lightening bolts in head... slapped off surface by pot holes to pivot side ways in flight before strike down from perfect fine straight ahead the instant before...
Upper spine and brain swelling sure screw with my sane thoughts for a while too.

On the 155 crank dyno the Gold Standard and tops prior 150 reports. Following the crank and wheel dyno reports over a decade, averages out less than 10% loss
to tire patch, closer to 9%, but for fair fudging no fibbing subtract 10%. implies,
140 rwhp! May not be up to that at salt flats of course - but oh my my bad boy!

Here's a E2 dyno and operator reports on power train loss.
http://www.nortones2.co.uk/
The man who drives the dynamometer advised me that almost any chain driven bike, from ES2 to GSXR1000, will loose 12-13bhp between crank and rear wheel.

The read outs below show 20bhp at the rear wheel. (This performance is comparable with my son's Suzuki Goose, quoted at 33bhp at the crank, so the Dyno man seems spot on!)

I have a little Villiers engined 125cc commuter bike.
It puts out a quoted 3 bhp.
It sure doesn't lose 12hp in the drivetrain.
More to this than meets the eye ?

Apparently factory dyno runs they always oil the chain before taking readings.

Ok so yours is outside the rule of thumb quoted. Fred's Norton is still a chart topper.

Hey Steve, time to tighten up that there loose stool. Ya might fall off !!!

just kiddin'.

I think something's changed inside me. I understand the concepts when you explain stuff in your way. I hear ya.

You need to wear earplugs beside the Dyno . Im sure he said PERCENT of Horsepower . :idea:

Refreshing remark fulauto, kind of pensive making isn't it, or should be. Peel was absolutely Neutral tires touching or both lifted no pilot effort to keep same angle, only throttle effort to change angle, forks did themselves, then relax again. I'm scared to change too much of what I know works, right off the bat. But might have years to play with it. I'll know what limits my fun though as it all comes through so un mixed up clearly to its source in Peel. Could she take 150 mph on rough salt, don't know only done the ton on THE Gravel to find very strange things happen on how tires follow ruts walls to inside and climb to tops of humps like a belt drive on arc'd pully flat. As a long as i could keep accelerating was like a dirt bike lifting front over stuff, as soon as power reduced or ran out of the front loaded so all hell breaks loose to slow into control again. A shift could only be done dragster WOT-kill button fast or front would instantly load up and rudder horribly. Full Gung Ho or else.

Steve Many 920 dyno ~100 at crank and ~90 at tire, which implies 10% power train loss, but the E2 dyno site rule of thumb says expect that similar 10-ish hp loss regardless of horse power [in sports bike range]. I assume its innate d/t size/type of drive train. All's I sort of know is - ain't no 20-30 hp loss from crank to rear patch in Norton like set ups, maybe not even 15hp. Motor world at large would accept 140 rwhp.

They make special conforming muscle/joint tape re-enforcements for spine, shoulders limbs, so if I ever attempted a speed run I'd re enforce over that with duct tape and air bag neck protector plus rabbit foot key fob.

Reading this new pinnacle in Norton twin power temps me to ponder further on Peel's deal but for sure not right off the bat.

hobot said:

Ok so yours is outside the rule of thumb quoted. Fred's Norton is still a chart topper.

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Indeed.

But so does that mean if we fit the drivetrain out of that little Villiers, it will only lose half a horsepower, not 40ish horsepower ??

It may not last long - but that is a heck of a difference...

hobot said:

The man who drives the dynamometer advised me that almost any chain driven bike, from ES2 to GSXR1000, will loose 12-13bhp between crank and rear wheel.

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That doesn't strictly make any sense either ?

If a std Commando does that, and you add supercharger and double the engine power output, why would the transmission absorb any more power than it did previously....

Losses are the result of transmission efficiency expressed as a percentage. EG for well lubricated and correctly rated/sized parts a chain is about 98% efficient per sprocket, a spur gear set (pair of gears) about the same, ball bearing friction similar, bushes 95%, seal drag (negligible?). So in 4th you could lose up to 4% in the primary, 4% in the box and 4% drive to rear wheel. In theory that would be higher since 1, 2, 3 include an extra pair of mating gears. In 4th only one pair of gears is meshed. Some losses should be added for rear wheel bearings. That's really basic stuff and 12-15% is about right. Thats why a 12hp engine doesn't go negative on HP!!

hobot said:

Steve Many 920 dyno ~100 at crank and ~90 at tire, which implies 10% power train loss, but the E2 dyno site rule of thumb says expect that similar 10-ish hp loss regardless of horse power [in sports bike range]. I assume its innate d/t size/type of drive train. All's I sort of know is - ain't no 20-30 hp loss from crank to rear patch in Norton like set ups, maybe not even 15hp. Motor world at large would accept 140 rwhp.

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Steve, you've got to be careful quoting both crankshaft and rear wheel hp, and then drawing a conclusion about loss. Most (not all) of the horsepower numbers you see quoted for bikes are taken from rear wheel dynos, some driven by the drive chain, and some driven by friction from the tire. The crankshaft numbers you see are usually extrapolated from the rear wheel numbers, using a standard transmission loss percentage. The loss percentage is either provided by the dyno manufacturer, or derived from the operator's experience. These correction factors are notoriously unreliable. All the dyno numbers I've seen from Steve Maney were taken from a rear wheel dyno, and extrapolated to get a crankshaft number. I haven't asked Jim Mosher yet, but I suspect his numbers for Fred's bike are done the same way, a rear wheel measurement extrapolated to a crankshaft number. The 107 rear wheel horsepower for a 920 engined bike on nitrous oxide sounds plausible, but the 155 engine horsepower number doesn't sound right. Having said all that, that 107 rwhp is the highest I've seen mentioned for a Commando engined bike, and pretty impressive. It should certainly be enough to give them a class record eventually.

Ken