birdbrained idea continued

[buckles]

mucho head scratchin and i have taken a few more steps into the heavy oil abbys, so got the perkins engine this is going to go into a ural frame by the way, but i did not want to use the russian box and final drive. I have been running a ural outfit for a couple of years and thought a break from the pisspoor bearings seals etc etc might be a step/ ride in the right direction. Got my hands on a bmw box, five speed too, hopefully this should get me a better top end speed, also going to use a bmw final drive rear wheel assembly. These bits should be with me in a couple of weeks so i might at least be able to get started. The next big hurdle is clutch onto the flywheel then making a bellhouse, although i called into a local foundry and was told that if i make up a pattern i can have one cast for about 50 quid. So what grade of aluminium would be best or will it not matter so long as its thick enough. All feedback welcome, Andy.

[smokyjoe]

Hi Andy,

Although I've never made a bike bellhousing I've done a bit of aluminum casting. I don't know how much experience you have had with this sort of thing but it isn't rocket science, it is technology literally thousands of years old! Only difference is that today we don't have to use bits of leather and beeswax to finish our wooden patterns.

You'll need a "shrink rule" to do all your measurements when laying out the pattern after you get your design set, this will make the pattern a little bigger to take into account the shrinkage of the alum. when it cools. I think aluminum is roughly 1/8th inch per foot, it's been a while so I'd ask the foundry guys don't take my word. These are available from pattern suppliers. One here in the US is Freedman, but I'm sure that they are more in the UK. A wood lathe or metal lathe is handy to turn the wooden pattern pieces, this goes like any other woodworking project except that you can fill any imperfections with auto body filler and it doesn't have to look pretty! Be sure to have enough draft on the pattern sides so it will pull out of the sand easily, and don't forget to fillet the inside angles so the sand releases. Here in the US there are few foundries that will let you make the pattern, sounds like you found a good one that will work with you. I'd pick their brains and get as much advice as you can as patterns, especially of bigger intricate pieces can be tricky. I'd go to the foundry and look at some other peoples patterns and see how they are made. I'm not a woodworker so I've made pattern pieces using a milling machine, lathe, and drill press with good results. You can make a mock-up out of wood to bolt up to your engine and trans to see it all fits, do your measurements and then lay out the pattern using the shrink rule. This is the "old school" way before CAD/CAM and all that fancy stuff came into being.

There is lots of info on the web on home casting and patternmaking, one website that comes to mind is metalweb.org I think it is called.

Another word of advice is that I would have a couple of pieces made, just in case you goof up in machining. There is usually a setup charge for the job, and the total job price may not be much more for 2 or 3 pieces than 1. for And, if you turn up a perfect piece from your casting, I'm sure someone will buy your spare casting and possibly that will pay for your piece, too! Also, make sure the alloy type they use machines well, I've made castings of aluminum that were so gummy they were impossible to machine. I've found that the alloy used for pistons, heads, and other automotive uses was the best to machine. I am sure your foundry will steer you to the right mix if they know what your plans are. You don't need the bellhousing any thicker than what was on the bike originally, except that thicker will give you more material to work with and to a point will make it possibly easier to cast, but the tradeoff is making the "bell" part too thick to fit in the mounting bolts! After you get it all set give it a few coats of varnish sanding in between with fine paper to get it nice and smooth. Again, check with the foundry guys on what to use. Talk to their patternmaker if you can, these guys are true artists and are few and far between in these days (I used to work with a guy 20 years ago who was a machinist and patternmaker for Indian Motorcycle and many days I wish he were still alive so I could get his advice when I'm in a fix! He was a dear friend and a great mentor.) Learn all you can from them and pass it on!

If I remember what a BMW tranny and bellhousing is like, perhaps you could have less work casting (or machining from a chunk of plate) an adapter plate to mate the BMW bell to your engine, or just make up an adapter ring. I've done this back in my misspent youth building hot rods when I'd adapt a big Chevy V-8 to a tiny 1930's Ford transmission. Then I'd floor the gas pedal, pop the clutch, and watch the innards of the tranny blow out of it's case all over the road, then go back to the garage and do it all over again. There are lots of Dieselized BMWs and Dneprs out there to get some good ideas from.

Good luck, and keep us all posted on your progress!

Brad

[Crazymanneil]

This is an interesting thread! Maybe I should cast up the cover for my primary belt instead of making it out of sheet metal...

n

[smokyjoe]

You could cast a pretty cool looking and functional cover, polish it and it would look factory! There is much info available, mostly 100 year old books (or reprints). I have some very old original books and a number of reprints that I've used. There are some excellent reprints available from Lindsay Books in the US and they ship all over the planet. Excellent people to deal with, I've bought probably 20 of their books. I can't remember the names of them, but they have a couple of good no-nonsense books on patternmaking from back in the days when engineers and machinists learned their trade by doing instead of sitting in a classroom.

Lindsay also has some books on making your own foundry to do everything up to iron castings, but for the best results I'd let the professionals do the actual casting unless you'd rather learn to be a founder than spend time riding your bike!

I've made parts for antique engines that were just unobtainable anywhere else. When replacing iron parts with aluminum, I'd make bushings of steel to fit into parts that take wear, once they were painted it was almost impossible to see the difference.

Never made anything as big as a primary cover, but it shouldn't be too hard to womp up a pattern. I imagine that there shouldn't even be much machining that couldn't be done with a drill press, sander and a few files and scrapers to finish it off.

Check out the stuff on his website, there's even a guy who made a STEAM POWERED motorcycle like one shown in one of Lindsay's 1900 reprints!

Here's the link: www.lindsaybks.com/

[Crazymanneil]

Ta for the info's. Doubt I'll get something cast in the next 6 weeks but maybe after....

n

[buckles]

The perkins engine I am going to use in my ural frame.

[buckles]

As soon as I have got this running, only had it two years!

[smokyjoe]

I'm getting interested in using some kind of Russian BMW clone for my "future" Kubota powered bike after seeing these nice builds. I was thinking of using a Honda CB1000c chassis that I already have and a CVT, but after looking closely at the pictures of the Urals and Dneprs and seeing a beautifully restored early BMW my ideas are being swayed. These old shafties are real cool. Anyhow, I have to finish my one-lunger project first.

Keep us all posted of your progress including what you do to mate up the Ural clutch to the Perkins flywheel. Is yours a 4 or 5 speeder?

Thanks,
Brad

[OilyPhil]

Dont know if its any use to you but I'm using the rear part of the BMW crankcase, sawn off then milled to the required depth then welded to an adapter plate to mate my BMW gearbox to a kuboto D950.

Phil

[buckles]

I was talking to a mate today and we got on about the gearing and final drive on my outfit. The bevel box is bmw r45 and that bike should rev to about 5-6.5k and achieve 98mph, my perkins will rev out at 3.6k so does that mean i can make a top speed of around 45-50 mph. I am using the r45 5 speed box but i think its the bevel box gearing that is the key . Also i may make up two plates one on the engine and one on the gearbox and space them apart at the distance dictated by the clutch and flywheel, then cover the gap to keep the rain out, that idea seems a lot easier than casting a bellhouse/cover which i originally intended.

[OilyPhil]

According to my info your bevelbox is 3.89:1 (should be stamped 35/9 on top of casting just infront of mounting flange, the highest you can get is off a R100RS at 3.00:1 (should be stamped 33/11). Swapping to the RS bevel box will give you a 13% increase and get you another 8mph ish . There is a higher ratio of 2.91:1 32/11 but was used on mainly us models and are very rare.

Phil

[smokyjoe]

OilyPhil,

You'll have to post some pictures of that gearbox! Sounds like a nice job. Like I've said before in other posts, the Kubota engine I have is for after I make all the mistakes on the Hatz/Suzuki (Hatzuki)! I am still undecided how to do the Kubota bike, but the URAL/BMW/DNEPR route would make a nice, clean looking machine. I'm glad that there are a few choices in drive ratios available.

Thanks,
Brad

[buckles]

According to my info your bevelbox is 3.89:1 (should be stamped 35/9 on top of casting just infront of mounting flange, the highest you can get is off a R100RS at 3.00:1 (should be stamped 33/11). Swapping to the RS bevel box will give you a 13% increase and get you another 8mph ish . There is a higher ratio of 2.91:1 32/11 but was used on mainly us models and are very rare.

Phil

Hi Phil, thanks for the info.
I have just been to look at the ratio stamped on my bevel box and is marked up at 37/11, does this mean then that i will have a lower top end speed than a box with with a ratio of 33/11. Thanks in advance, Andy.

[OilyPhil]

Yes, your ratio is 3.36:1 which is less than the r100rs box at 3:1, if you were to change boxes you could increase your overall ratio by just over 11%. I picked up my box off ebay for £30, but they usually go for around £100.

Phil.

[Diesel Dave]

I really admire you shaft drive boys, it's a real challenge.

There's a lot to be said for chains......duplex for primaries and simplex for final.

Inspiring though!

Dave

[Sphere]

Actually I think the joke's on us chain guys. They do hard work to get it going, but in return get virtually maintenance free machine.

[buckles]

I really admire you shaft drive boys, it's a real challenge.

There's a lot to be said for chains......duplex for primaries and simplex for final.

Inspiring though!

Dave

I have to admit i know complete cock all about gear ratios and engineering really, i am making this up as i go, as a problem Arises find the solution guess we will have to wait an see .

[Sphere]

Good plan buckles, don't let it hold you back.

[buckles]

According to my info your bevelbox is 3.89:1 (should be stamped 35/9 on top of casting just infront of mounting flange, the highest you can get is off a R100RS at 3.00:1 (should be stamped 33/11). Swapping to the RS bevel box will give you a 13% increase and get you another 8mph ish . There is a higher ratio of 2.91:1 32/11 but was used on mainly us models and are very rare.

Phil

Ok then, sorted myself a 32/11 bevel box, not cheap but as the adverts say " your worth it" got to pick it up on Sataurday. Also i have struck upon the idea of building the bike as a rat at first and running it for about a year to do all my R+D so that the bike evolves, then stip it and do all the finishings, coatings etc. Hope fully the flywheel, clutch, engine/gearbox should be ready soon too. Andy.

[mark_in_manchester]

Andy -
If you did choose to go the Russian route, 4th gears pairs at 1:1 and bevel sets at 3.2:1 are the highest available and can be bought over the web from oldtimer garage in Poland. I have these in a Daihatsu-Ural I'm just finishing - Ural bevel boxes are 10-20 quid on ebay and gears are fairly cheap. These ratios work out to about 109mph at 5000rpm with 19 inch wheels, so if your max revs are 3600 then with my transmission you'd be up at 78mph. You can work the engine revs / speed thing out like this:

Engine rpm*60 = engine revs per hour (engine rph)
Engine rph*4th gear ratio*bevel box ratio = rear wheel rph (need to make sure you put those ratios in the right way around...is it 1:3.2 or 3.2:1 - common sense when you think about it).
For each rev, wheel advances along the road by a distance 2*pi*r, where pi=3.1415927 and r is the radius of the wheel and tyre, measured from the spindle to the point of contact with the road (ideally including your weight on the bike, which will sqash the tyre a bit!).

So - rear wheel rph*2*pi*r = meters per hour, assuming you measured r in meters. Divide by 1000 to get kph, and if you want mph then a rough convension is to divide by 10 and then multiply by 6 (60mph~100kph).

Casting ideas are nice - I did it by 'cheating' with two 10mm thick steel plates and a set of 8 M10 bolts as 'legs' with Al spacers. Ural clutch is *very* rattly disengaged - Bell Housing would be nice one day. Whose foundry did you talk to re: casting?

I'm only in Manchester - you're welcome to come over and have a look at the bike some time.

Voshkod looks nice - everyone says electrics are terrible! What about your MZ ES250 picture, with Stoye sidecar - is that yours too?

cheers
Mark

[johnfireball]

Hi buckles,
dont forget that as the bmw clutch plate wears the splines on the clutch plate move further up the gearbox input shaft splines, so 4mm clearance must be allowed for when spacing out the bellhousing plates.
John.

[buckles]

Hi Mark, Thanks for all the info and I would love to call in and have a look at your outfit.As for my bike, I have thought about this loads over the last few weeks and decided to use BMW clutch, gearbox,prop and bevel box- rear wheel etc. This should achieve better reliability, don,t fancy 109 mph on anything ural, it would be like a re-entry from space . But it also means more work in the build, no reverse and not as much top end as i would like, but a compromise, 60 mph or so should be ok. Will also use plates spaced apart to mount the gearbox to the engine and perhaps cast something at a later stage, I will find the foundry's address out for you. My engine and box should be ready soon so I can then start work on the frame. That voskhod is right pain, someone has fitted a battery to it and I cannot get my head around the electrics I may just rip the lot out and wire it as it would have been from new. The MZ is not mine it was at the krystall rally this year, me and three mates did it on honda c90 cubs, 1800 miles two weeks no problems at all! it was a fantastic trip, we are hoping to go back in a year or two but further north into the arctic circle. Cheers Andy.

[mark_in_manchester]

Andy -
You're welcome to come over (my bikes a solo, not an outfit). I like the re-entry metaphor - some drag chutes would be very useful. I met a guy and a girl on C90s at some eastern block rally a few years ago, who had 'international pizza delivery' stickers made up in German on the back for continental rallying...don't suppose it was you?
cheers
Mark

[buckles]

Hi buckles,
dont forget that as the bmw clutch plate wears the splines on the clutch plate move further up the gearbox input shaft splines, so 4mm clearance must be allowed for when spacing out the bellhousing plates.
John.

Hi John, thanks for the info, I could not get my head around your post at first but as I thought about it today it made sense, simple really but I would have overlooked the wear aspect had it not been pionted out, top stuff. Thanks, Andy.

[buckles]

Andy -
You're welcome to come over (my bikes a solo, not an outfit). I like the re-entry metaphor - some drag chutes would be very useful. I met a guy and a girl on C90s at some eastern block rally a few years ago, who had 'international pizza delivery' stickers made up in German on the back for continental rallying...don't suppose it was you?
cheers
Mark

Hi Mark, Will try and get over to steel some idea's,, ahem, check out your bike in a couple of weeks, not me on that occasion, ta, Andy.

[buckles]

My project just took another direction, I have been after a diahatsu for yonks and I could not believe it when one came up for sale a few days ago, so I spoke to the seller, went and had a good look around it and bought it for my bike!. £250.00 engine and box, a good runner but in need of a clean, a rocker box gasket and a cam belt. This now means that the perkins is up for sale, I have £800 in it if anybody on here wants it other than that it will go on ebay for £ 1000, I could deliver it at a small cost. Andy.

[mark_in_manchester]

Andy -

I probably have a spare rocker box gasket, and also a spare Daihatsu bottom end (bores no good but crank, rods and pistons OK) which I'll be weighing in soon since I have another spare - if you come over, you might want to come in a car...

M.