New Build... third time lucky!

[realnutter]

Hi All!

This is my third go at building a diesel bike... the last two were curtailed by house moves etc....

But now I'm settled in my own place, with a freshly built 7' x 7' shed to work in.... and this engine:

http://www.youtube.com/watch?v=wCJEbvOdlUA

It's a Honda 479cc v-twin of about 1970 vintage...originally a E4000E genset.... there's now two videos of this machine on youtube... one of mine, and another by someone else....but that's ALL I can find on the web!!!!

I'm planning on putting it in the bike with the crankshaft transverse, using the original belt drive to a 2-stroke bike bottom end....nice enclosed clutch and gearbox...and then chain to the back wheel..

I have no parts yet, and little spare money so it'll be a slow build!

Matt

[Stuart]

Matt,
I don't know if this will be of any help but I have a parts manual for a Honda Diesel V twin GD100. Studying it closely and comparing to your Youtube Video it looks quite similar. Labelled up as year 1968.

I could post it to you and if you want maybe you could copy and return? Or I could bring it to the rally if you're coming?

Stuart

[Dougy]

Good vid mate, allways good to mention flange whenever you can too .
I know what you mean when you mention how heavy the things are, mines only a small single cylinder an now I've taken the tank an exhaust off its heavy and awkward to move, and yours looks a lot bigger ! pity about not seeing the engine though, but it will sound awesome with the right pipes.

[realnutter]

I've decided to go Guzzi style!

The engine's too pretty to hide in it's shrouds, so I'll let the motion do the cooling!

Scored a BMW R100 rolling chassis to fit it in, and have had a close look at Mouse's v-twin.....my engine will mate to the BMW gearbox more easily than his!!

And yes, I know I'll be flat out at 50!

[realnutter]

OK, so tonight I've stripped all the odds and sods off my BMW R100 chassis, and begun to think about squeezing the engine in....

The lower frame rails of the chassis are about 25mm too close together to get the sump between, so I reckon a little spreading is in order.......

So the question is, how? I'm worried that if i just jack them apart, one side will move more than the other......

So I figure, break out the oxy, heat one side to a nice red colour, and jack it 12mm or so.... then repeat the process on the other rail....

The theory being that the heated rail will always be the one that moves....

Thoughts, please?

[realnutter]

Wish I'd made it to the big knock.... but thanks to a friend who did I now have these pics of my engine in use!




Looks good! however, they do say to me that my engine runs the other way round to what I expected!

Re-think time!

[Stuart]

As I mentioned in the email the manual I sent got returned from some other bloke! Wrongly delivered it would seem. I shall repost very soon but been a bit busy of late

[andrewaust]

That's a sweet looking engine realnutter, very nice indeed. Be sure to keep us posted



A

[realnutter]

OK, so time has passed, and I appear to have done nothing........

This is not the case! I've been busy researching! And designing!

Due to my engine running backwards to "normal" I cant go with the original guzzi style layout..... so I'm going harley-style....

I have to put the flywheel on the right, to get the direction of rotation correct. For a gearbox, I'm going down the 2-stroke-bottom-end route, replacing the crankshaft with a through-axle, and driving onto the end of that - probably by twin v-belts.

The repercussion of this is that I will be running the whole transmission backwards! I'm still going in on the fake crank, and driving the back wheel from the gearbox output sprocket, but the whole assembly will be flipped over (and stood on end) to get the input and output on the right hand side of the bike......

I don't think this will be a problem, and might actually be beneficial, as I'll be using the less worn faces of all the gear teeth!

So now the hunt is on for a RD250/400 bottom end with a mangled crank, lets hope e-bay turns something up this week as payday looms!

I'm going for the RD as it's a twin, so the fake crank will be well supported (4 main bearings), and also because the little helical gear that drives the clutch basket bolts to the crank. On some bikes (Honda NSR springs to mind) this gear is machined into the material of the crank, which would make the whole process practically impossible!

If anyone knows the situation regarding this gear on other two stroke bottom ends (whether good or bad), I'd like to know, so I can compile a list....

[sbrumby]

Done it. RD350, only need straight shaft 30mm in dia from memory ,and this comes out left hand side of bike so I dont understand your talk about backards rotation.

[realnutter]

Sam, my flywheel needs to be on the right, And I can only take drive from the flywheel.....

[coachgeo]

Sam, my flywheel needs to be on the right, And I can only take drive from the flywheel.....

think what Sam is saying.... drive from flywheel right side of bike as you need. say 1:1? chain-n-sprocket off flywheel to jackshaft. Jackshaft runs to other side of bike, braced in pillow block bearings. Another chain from jackshaft to a say a harley Ultima tranny? Tranny then attaches via normal chain arrangement to rear sprocket left side drive. (which also now has reversed your rotation) Or.. use CVT in place of Ultima. This may allow you to put the bulky side of cvt facing inward instead of outward narrowing the bike width by tucking it all in tighter.

[realnutter]

I understand, coach...but i want to avoid the intermediate jack shaft, and thus one belt or chain....

so 1:2 belt from flywheel end of crank to dummy crankshaft in the 2-stroke cases.... and then chain to the back wheel.... at about the original ratio.... keeps my belt/chain count low....

And I dont see a problem with spinning the gearbox backwards....

[realnutter]

Except, now I do!

The crank/clutch gears on all bikes that I know of are helical!

Helical gears produce end thrust on their shafts....which in the case of the gearbox input shaft, is taken by a thrust bearing behind the clutch..

Reverse the direction of rotation, and you reverse the end thrust.....

[coachgeo]

Except, now I do!

The crank/clutch gears on all bikes that I know of are helical!

Helical gears produce end thrust on their shafts....which in the case of the gearbox input shaft, is taken by a thrust bearing behind the clutch..

Reverse the direction of rotation, and you reverse the end thrust.....

Can you weld together a new case with thrust bearing on both sides or reinforce the one side and add a crush bearing?

[sbrumby]

I understand what you wanted to do and I think it will work. I think you will find the RD gearbox has straight cut gears and only the drive to the clutch from the crankshaft is on the slant. so the thrust could easily be overcome by putting collars on the new crankshaft to stop it moveing.

[realnutter]

With you on the crank collars.... but there will also be end thrust on the clutch shaft...which will try to pull the shaft out of the casing, rather than push it in.... there's a thrust washer behind the clutch, i believe, but not one at the other end of the shaft...

[sbrumby]

Yes what you say is true but dont forget if the crankshaft on normal rotation is pushing on the clutch, what hapens when you are engine brakeing ? surely the opposite is true ? anyway why cant you turn your engine round ? If you drive the gearbox backwards then your rear wheel will have to be turned also, If its a drum brake it could thro up some other problems. if its a disc it probably wont matter.

[realnutter]

I dont want to insult yr intelligence, Sam.... but if i turn the engine round, then I'll have a bike with several reverse gears, but no forwards ones!

[realnutter]

Ah-Haaaaa

I have found the answer to my problems!!!

Get an engine that is the mirror image of normality!!!!

Like this one!

http://cgi.ebay.co.uk/Harley-Davidson-M ... 4cf83d55bf

[realnutter]

So.. I bit the bullet today!

Having just failed to secure my Rotax bottom end on Ebay.... I bought a whole engine!

The bottom end went for 57 quid...and i paid 150 for a complete engine.... i figure i can strip off the bits i dont want, and sell them on ebay, I'll have head, barrel and piston, crank, starter motor, balancer assembly, and oil pump as surplus... hopefully get most of that 150 back!

Slowly but surely getting there!

[realnutter]

OK...so time for an update.....

As I mentioned before, I've acquired a Rotax 350 engine to use the gearbox from.... Whole engine cost me £150..and I made £180 on selling the bits i dont need..so a result there!

My chosen chassis is a BMW R100...I originally planned to do a guzzi style v-twin... but my engine goes round the wrong way! So it's Harley layout!

The BMW chassis is not big enough to hold my engine...so cutting and shutting is required...so the first step was to weld in some cross braces to keep the lower rails parallel after they're cut out.....

http://farm7.static.flickr.com/6188/615 ... c753_b.jpg

Most of the rest of the chassis will be re-attached to the lower rails (but further away) later....

So, now having the lower frame rails with plenty of headroom, I can start to mock up the engine, gearbox, and rear wheel, to get a feel for overall length, and the issues I will face.....

http://farm7.static.flickr.com/6159/615 ... 43da_b.jpg

It isn't looking too bad! I'm going to make it a hardtail, partly for simplicity, and partly to keep the length down.... The gearbox is going to stay horizontal... I need to fit an alternator, and above the gearbox seems like the ideal place!

The engine can come forward in the "cradle" but another 2-3 inches, which will help with length!

So, next steps are to extend the lower rails backwards (and kinked up) to meet the rear wheel spindle.... line up the sprockets on wheel and gearbox, and get the gearbox mounted... and then finally line up the engine pulley and gearbox input pulley...and get the engine mouts made.... then I can think about putting the steering head back on!

Here's another view of the bits on my bench....

http://farm7.static.flickr.com/6198/615 ... b1c4_b.jpg

Onwards and Upwards!!!!

[realnutter]

Well, I had some holiday to use up, so took a week off work to push on with the build.... Hopefully by friday I will have a rolling chassis!



Wasn't helped by my 25 year old welder packing up on me early afternoon...fortunately a mate lent me his.. (Thanks Nigel)

[XLerate]

Impressed with your simple logic in your build! Weld up the bottom cradle defining the layout, then step by step fit the bits & pieces onto cradle, then build the rest of the bike around it all. Pretty fool proof, lowers the uh-oh factor a whole bunch.

Looking good & I'm sure it's going to be one fine ride!!!

[realnutter]

[alexanderfoti]

Looking good, eager to see the end result!

[zarquon]

http://farm7.static.flickr.com/6213/630 ... 2418_b.jpg

Nice one! Good luck with the build!

Do you have the link to the Flickr Set of you images? It's not the one in your signature.

Rafael

[zarquon]

Here you find all the pics of realnutters build on flickr: http://www.flickr.com/photos/29632879@N05/