Dunstall and 905 pics now online

Hello folks

It took a while to get my homepage reworked but now you should find some pics under "projects". The frames are more or less ready for assembly - they only need a couple of small parts added for the fitment of coils, seat, tank etc before they go to the platers. But first I need to find the time to make some tanks, seats etc ;-)
Most of the 905 engine is in the final stages, currently we make the mould for left crankcase half - will be much stronger and have an extra bearing for crank. The new oilpump drawings are ready so we will have made the first pump within a couple days. It has got 3-times the output, anti wetsump valve and oilpressure control - all of it integrated in the body. A new primary is almost ready and a 6speeder will be designed in the next few weeks. This gearbox will be shiftable left or right, 1st gear up or down.
Go to www.britishclassicbikes.de

Cheers

Hartmut

Forgot to add: you have to click on the "Aktuelles" sign on the startpage. Then you can check out the upper three postings.

WEAL Norton said:

It took a while to get my homepage reworked but now you should find some pics under "projects".

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Schick, schick... :wink: Although I'm still tempted to nickname the frames "the world's fastest Ofenrohr".

Most of the 905 engine is in the final stages, currently we make the mould for left crankcase half - will be much stronger and have an extra bearing for crank.

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Could you elaborate a bit on the details of this extra bearing? Do you mean a third bearing in the middle? I don't see a provision for that on the crankshaft so I'd be very curious how you achieved this.

Wait, the flywheel looks a bit suspicious: You're not planning to use that as an oversize plain bearing, are you?

The new oilpump drawings are ready so we will have made the first pump within a couple days. It has got 3-times the output, anti wetsump valve and oilpressure control - all of it integrated in the body.

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Sounds promising! Some questions: Did you modify the scavenge pickup points? Head evacuation? Would it retrofit into a STD installation or is it one of the installations where the pump occupies the old mag location?

A new primary is almost ready

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Additional outrigger bearing?

Questions, questions....keep the info flowing! :wink:



Tim

I never liked the outrigger bearings: The 3rd bearing sits in the middle of the 55mm primary so it helps to prevent bending loads of the primary and keeps the crank straight throught the ignition pulses. Same applies to the new gearbox. The output bearing sits outward of the sprocket (choice from 14 to 19 teeth as the primary ratio is a bit quicker) - thus we get more space inside the shell and can make some realy strong gears - so even the 6-speeder should survive the punishment of my MX outfit :mrgreen:
Of course oilpump drillings are heavily modified: the new diameter of these drillings is 9,5mm as we couldn´t flow the amount of oil with less diameter. As the head is not able to flow that amount of oil through its return drillings there will be an outward line connecting the inlet part of head to the returnpump (the exhaust side should be okay to flow the oil through the new cam followers). Thus we get rid of the drilling near right inlettrack - this will be closed and I can open the track a little further for better breathing.

Cheers

Hartmut

Can you change the weight of the flywheel cheeks? They appear to be 2 piece.

Tintin said:

Could you elaborate a bit on the details of this extra bearing? Do you mean a third bearing in the middle? I don't see a provision for that on the crankshaft so I'd be very curious how you achieved this.

Wait, the flywheel looks a bit suspicious: You're not planning to use that as an oversize plain bearing, are you?

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It woud be impossible to get a big bearing like that to spin freely enough to allow kick starting, the bending of the crank would finish it off if it could turn freely. They did the right thing by putting most of the weight of the crankshaft closer to the bearings rather than in the center as it is (was) done on the stock Norton, even Steve Maney's crank is not done as well.

Very impressive bikes, bravo

Jean

Jeandr said:

Tintin said:

Wait, the flywheel looks a bit suspicious: You're not planning to use that as an oversize plain bearing, are you?

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It woud be impossible to get a big bearing like ...

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That's why I asked... :wink:

But Hartmut has quite a reputation here in Germany and it's not the worst! Good luck with the project, looks very promising IMHO.


Tim

The center flywheel of the 905 is completely round so it should act as a vibe damper. All needed balance weight is on the outside cheeks.
But for those Twin riders that are worried that their cast flywheel will break someday and destroy most of the engine (don´t ask how I know this...) I have made another version as well: the triangular flywheel is made from very good steel (16Mn Cr 5), the boltholes in the cheeks and flywheel are machined to 9mm and the big bolt in the center has nuts to tighten as well. All bolts are ground to size and very good material. So you get a crank where all bolts locate the cheeks in their position with one extra clamping bolt in the center. The balance weights are bolted to the flywheel and could be taken away for fine-tuning when you change pistons. The crank is much stiffer than stock and reduces loads on bearings and cases. Could still be used with stock rods and pistons etc.

Cheers

Hartmut

Weal

Cant see if you supply the hubs used on the Dunstall?

My friend sold the Dunstall (Pickrell 68 bike) to the National Motorcycle Museum. I have to say it is one of the nicest riding positions. The spine allowing a very narrow seat & tucked in (knees) riding position.
Look forward to seeing the finished bikes.
all the best Chris

Must admit my translation website is struggling to put your website into understandable English.

Hey Hartmut

Those tappets are pretty extreme, have you run those with a race cam before or is this an experiment?

WEAL Norton said:

The The balance weights are bolted to the flywheel and could be taken away for fine-tuning when you change piston.
Cheers

Hartmut

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Very cool Hartmut. Are the balance weights matched to fit a specific flywheel or are they interchangeable? We could have 2 sets!

To answer a few questions:
The new cam followers are made from casehardened steel and get a special coating on the foot for extra durability. They are not tested yet but will be in a couple weeks when the 905 is ready.

The triangular flywheel is exact the same weight for all cranks.The balance weights are located right and left of the flywheel. They are each located by 3 keys and held together by 2 screws - so shearing load is not on screws but on the keys. They can be unbolted easily and changed in shape, weight etc for any thinkable application. So you could have different weight sets for your crank should you wish to play with balance factors etc... Therefor we can rework a crank to any combination of conrods and pistons, giving any desired balance factor.

The Dunstall: my frame is not a slavish copy of the original but more a copy of the idea. I incorporated a few changes that (I think) will be good such as holding the engine plates with the swingarm spindle as well. The original Dunstall uses only 2 points at the rear to hold the plates - I use 3.

And those frames where not called "Ofenrohr" (Stovepipe) but " Abflußrohr" (drainpipe)

On monday evening we will put a std 750 engine on the dyno to see where we start - my dyno contraption is ready, it takes only 5 mins to change a complete engine. Next job is machining a crankcase to be able to change cams without dismantling the engine. I don´t like the idea of tearing down an engine completely only for changing the cam. We have 5 different cams to try so I can save a lot of work by machining the right crankcase a bit :mrgreen:


Cheers

Hartmut

Dunstall hubs: I haven´t copied them but made my own as I am using modern disc brakes all around. The new 6-speed gearbox will give 235 kmh at 7000 so I like to have some proper brakes.....

Cheers

Hartmut

Hartmut

I was not suggesting that the hubs were Dunstall copies, Just I think they look fantastic. Will you be making any to sell?
Thanks Chris

Chris said:

Hartmut

I was not suggesting that the hubs were Dunstall copies, Just I think they look fantastic. Will you be making any to sell?
Thanks Chris

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No problem - if you want some just contact me.

Cheers

Hartmut

I want some too and a crank and rt side timing cover for starters. Problem is I can't afford it yet!

I hope your sales get going so well you can toss some money toward getting an english version of your web page up. Us english speaking blokes would like to gloat on your web site too.

Very innovative ideas and impressive work you're doing!

Try the IE translation feature, works pretty well.......

I'm on a mac with safari, I'll do a search to see what's available.

RennieK said:

I'm on a mac with safari, I'll do a search to see what's available.

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Babelfish

http://translate.google.com/?hl=en#

All kinds of stuff.

Of course I took years of German and all I can say is thank God for internet translators. :mrgreen: