Another Norton headed for Bonneville this year

This 750cc belongs to Rainier in Germany. Very interesting purpose built land speed racer. Note the strange ram air induction and air box. It looks like they've put lots of time and thought into it.


So that's at least 3 Bonneville racers headed for the salt flats in August. The dyno chart below looks too good to be true - maybe due to the ram air induction or an optimistic dyno.



Its got all the high tech light weight internal goodies with big valves and big cam but I don't know about the porting and other details. Its going to be an interesting year at Bonneville.

I don't know whether blasting across the Bonneville salt flats, while hoping the Norton motor stays together, would be 'interesting' or terrifying.

acotrel said:

I don't know whether blasting across the Bonneville salt flats, while hoping the Norton motor stays together, would be 'interesting' or terrifying.

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Just ship your bike over and find out for yourself!

acotrel said:

I don't know whether blasting across the Bonneville salt flats, while hoping the Norton motor stays together, would be 'interesting' or terrifying.

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Both...especially on those tires.

Impressive bike, amazing horsepower. Glad he's not running in my class.

Ken

My stomach is too big for that air box

With the gear pedal in that position the rider must have the ability to have his knees above his shoulders!

With that airbox and that seat / footrest relationship it would certainly be interesting to see a pic of the rider in racing position on the bike.

I’m sure it works well, the bike is too well built and too well thought out for it not to, it just doesn’t look like that in the pic posted!

Please tell me that the airbox has a rear opening panel?, and that in the picture it is open?

Like others, the riding position generally has me foxed.

SteveA said:

Please tell me that the airbox has a rear opening panel?, and that in the picture it is open?

Like others, the riding position generally has me foxed.

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The side tubes (that look like long flashlights) feed forced air into the air box and the pressure inside the carb bowls is balanced with the airbox pressure to prevent lean out (similar to the Kawasaki airbox system). I don't know about the sitting position but you can assume that someone has spent plenty of time practicing "tucking in". Maybe they decided there was less air resistance when jammed into a tight ball rather than having their legs spread out. If the HP figures are true than I'd say that they know what they are doing.

jseng1 said:

The side tubes (that look like long flashlights) feed forced air into the air box and the pressure inside the carb bowls is balanced with the airbox pressure to prevent lean out (similar to the Kawasaki airbox system). I don't know about the sitting position but you can assume that someone has spent plenty of time practicing "tucking in". Maybe they decided there was less air resistance when jammed into a tight ball rather than having their legs spread out. If the HP figures are true than I'd say that they know what they are doing.

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Yes, but Jim, surely the airbox does not sit on the seat when the rider is there?

SteveA said:

Yes, but Jim, surely the airbox does not sit on the seat when the rider is there?

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I imagine the riders butt is back up against the pad on the fender. We'll just have to wait till they get to Bonneville and hope for some action photos.

For a short time I had a race bike with velocity stacks a little too close to my zipper. I took so much ribbing from my friend Mic Ofield that I had to change it.

Hi guys, I am a friend of Rainer and will be travelling to Bonneville this August to support him. I have seen the development of the bike over the years. I can confirm that a lot of work went into the bike. It took some time and plenty dyno runs until he achieved the desired power. I hope it pays off.

I wonder what other Nortons will be competing there?

Joachim said:

Hi guys, I am a friend of Rainer and will be travelling to Bonneville this August to support him. I have seen the development of the bike over the years. I can confirm that a lot of work went into the bike. It took some time and plenty dyno runs until he achieved the desired power. I hope it pays off.

I wonder what other Nortons will be competing there?

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Ken Canaga with his Featherbed frame and Herb Becker/Andy Cox with their Commando frame will be running their 750s.

Herbs short stroke build is described in the following link with photos:
https://www.accessnorton.com/Norton...and-speed-motor-pics-3rd-times-a-charm.27619/

Hopefully Ken will post some photos and details of his bike.

Joachim - you could post some more photos and details of Rainer's build.

jseng1 said:

Ken Canaga with his Featherbed frame and Herb Becker/Andy Cox with their Commando frame will be running their 750s.

Herbs short stroke build is described in the following link with photos:
https://www.accessnorton.com/Norton...and-speed-motor-pics-3rd-times-a-charm.27619/

Hopefully Ken will post some photos and details of his bike.

Joachim - you could post some more photos and details of Rainer's build.

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This is a link to my landspeed build. Hoping to run it June 6 at El Mirage, if the lake is good enough to hold the meet. The bike is done and ready to go.

https://www.accessnorton.com/NortonCommando/return-of-the-nitrous-norton-2016.21511/

Ken

lutewizzard said:

With the gear pedal in that position the rider must have the ability to have his knees above his shoulders!

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With his bum on the seat and his tackle sat on top of that airbox, I guess it's the most natural placement ( assuming it's a male rider).

Ken
In your link above you mentioned welding the spacers onto the lifters. You can use silver solder because it has a lower melting point (1200 F) than brass (1700 F). Use low temp #56 silver solder. This way you don't disturb the brazing of the stellite pad. The lifters modified by Herb Becker below had spacers silver soldered to give them more overlap for the 480 cam. Looks like they were spot welded to hold the part in place for silver soldering - A clamp should take care of that and you really only need a little silver solder around the stem - concentrating the heat away from the pad.

jseng1 said:

Ken
In your link above you mentioned welding the spacers onto the lifters. You can use silver solder because it has a lower melting point (1200 F) than brass (1700 F). Use low temp #56 silver solder. This way you don't disturb the brazing of the stellite pad. The lifters modified by Herb Becker below had spacers silver soldered to give them more overlap for the 480 cam. Looks like they were spot welded to hold the part in place for silver soldering - A clamp should take care of that and you really only need a little silver solder around the stem - concentrating the heat away from the pad.

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Thanks, Jim. I only found out they were silver soldered after I welded mine. I was very careful to keep the bottom of the foot cooled in a wet rag when welding, and did very short welds, between which I cooled it more, so I don't think I'm at risk of having degraded the brazed joint. Next time around, I'll probably go with the silver solder.

Ken

A bit of background around Rainer's racer....I have to say I live in Perth, Australia and Rainer is in Germany so I dont know every little bit of the built but we are chatting often enough.

The built started a few years ago. Rainer decided to stay in the 750 class so it had to be a 750 Norton engine. We found a Commando engine in good shape (low 200000 engine number). Now the challenge was to get as much HP out of the engine as possible. The targeted figure was always around 85HP.

Rainer started with building the frame around the Commando Engine/gearbox combo...



After the basic concept was done, he concentrated on the engine. He got assistance by one of his mates who has been expert on tuning Triumph engines for classic racing for decades. The mods I know of:

- JS conrods and pistons (engine is now at 11:1)
- JS camshaft
- Aluminium barrels (I think Maney)
- stock crankshaft (this one had to be replaced during the process as the first one had a hairline crack after a few dyno runs at 8500rpm)
- 36mm Mikuni carbs
- original crankcase (oil pick up improved)
- original head (improved with reangled valve guides, 41mm/39mm valves, ported)
- Sachse electronic ignition

Gearbox and primary is stock Commando.








The first dyno runs were rather disappointing, too far away from the targeted figure. Plenty more improvements had to be made. The carburettors were changed to 36mm and jet sizes ajdusted on the dyno. Relatively short velocity stacks were used, pic below shows the final stage. The big box and the intake tubes you see on the original posts's photo are just to make sure that there is enough air even at high speed for the carbs. Apparently at high speeds there is a local air pressure drop 'inside' the bike due to the air stream around the bike. The air box is supposed to avoid that. All dyno runs were done without the box.



The exhaust had a massive influence on the power output. They experimented with the length of the reverso cone of the mufflers. At some stage a change increased the max power by about 10HP! During the built he got custom header pipes made up, not exactly sure how it affected the performance though. See photo below. Mind the port for Lambda sensor so he can do final adjustments on site, depending on the air conditions and the influence of the air box.




Short before the end they still coulndt get beyond 80HP. One of the final improvements was increasing the port size to the absolute maximum. So in the end they achieved the desired 85HP at the crank.

Someone here questioned the credibility of the dyno. One can never be sure but this dyno has been used for quite some time for classic Triumph tuning (very successful) and these bikes had been on other dynos as well. It shouldnt be too far off. But the truth will be on the salt

We are all very excited to be there either way.

Great stuff, thanks for the info and pics and good luck on the salt !