Oddball engines and prototypes

[WilDun]

……………………………………………. Smoke is the thing that makes electrical circuits work.
We know this to be true because every time one lets the smoke out of an electrical circuit, it stops working...…………………………………….

In France, in the Eighteenth century, the Montgolfier Brothers already knew about the power of smoke they flew on the stuff (or so they thought!) in their new fangled balloon . - in fact just like a lot of guys today who still fly around on smoke! - they don't know much, but they seem to be quite happy!
Then of course we musn't forget our favourite engine which has given us much pleasure over the years …….. and here, smoke must definitely be an indicator of better things to come! - Why does it keep escaping from our two strokes - maybe we need better seals?
It's the #1 cause of it's demise in bikes. Should still be ok in racing I guess, but not on the everyday road machine!


Lucas can't just go on taking all the credit for everything!

[husaberg]

I cant remeber where we were talking about hw Milyard makes the engines and the welding
but here he says he uses madrels vapour blasts the cases pre-heats and cslow cools and it details how he "line bores" them at home. which is quite intersting
I love the bit where he says it will be easy to add those extra cylinders

He even details how he fixes the mating surfaces

[guyhockley]

Apparently, there's a couple of blokes in the UK building Yam LC triple cases to order, made round about 15 so far.

[husaberg]

Apparently, there's a couple of blokes in the UK building Yam LC triple cases to order, made round about 15 so far.

Just like Rudi Kurth did 50 odd years earlier.
I had a poke about and there were a heap back in the day.

[guyhockley]

Yeah, I didn't mean that it was new, just that they've sort of "productionised" it. Less engineering involved with the LC separate cylinders.
Did Rudi Kurth build triples for other people? Not sure if he built Yamaha NVs ones or they just picked his brains.
Zeger sold complete bikes back in the day and more recently Paul Allender was selling Scitsu parts.
There's some disagreement over who built the first one, an Australian or a Brit, I believe. Got a Kiwi candidate?

[husaberg]

Yeah, I didn't mean that it was new, just that they've sort of "productionised" it.

Yeah i got that, do you have the CB write up of the LC700?

[guyhockley]

Think I've got a few like that... Want me to post them or do you already have it?
Or did you mean this one which is still online?

https://classic-motorbikes.net/yamah...treet-special/

[husaberg]

Think I've got a few like that... Want me to post them or do you already have it?
Or did you mean this one which is still online?

https://classic-motorbikes.net/yamah...treet-special/

Cheers i always thought it was Lc based
I found a pic of the case.
Where i got it from has pics of another way of doing it but i might have to register to find out.
http://www.aircooledrdclub.com/smf/i...?topic=30740.0

I wonder if a rudi kurth style but on both sides might be easier to accomidate.

[guyhockley]

I think the cleverest triple conversion is the DIKO 500. He put the ignition on the right hand side with a belt drive water pump off that, machined his own bolt-on case for the left with a blind main bearing housing. So his motor should be narrower and need moving over a bit less.

http://zweitakte.de/projekte/diko/tz500.htm

[guyhockley]

This is from a book that was way too big for the scanner so it's chopped up a bit oddly and you have to jump backwards and forwards to read each column from top to bottom. Sorry!

[guyhockley]

It was a german book translated into english called "Custom Bikes" but it was mainly full of racers?!

[guyhockley]

Cheers i always thought it was Lc based
I found a pic of the case.
Where i got it from has pics of another way of doing it but i might have to register to find out.
http://www.aircooledrdclub.com/smf/i...?topic=30740.0

I wonder if a rudi kurth style but on both sides might be easier to accomidate.

I have loads more 3 and 4 cylinder stuff I could post...if my computer hadn't just died!
I've seen a 500 done from 2 MZ250s which had the left gearbox case with a slot cut in the back for the chain to come out.

I think you're absolutely right that an extra pot on each side would be a more elegant way of doing it.

I have given it some thought in the past and have come up with a couple of different ideas but I'm not ready to share (which probably means everybody else has already thought of them)

[190mech]

Another possible clean 2 stroke,,Strato-Charged engine,it uses a 2 barrel staged carb,top barrel channels air through a slotted piston to allow a puff of clean air to help purge the cylinder,thus reduced unburned mixture in the exhaust..Ive got a string trimmer in the garage with this system,,the darn thing doesnt smoke at full throttle with a 32 to 1 mix..its said no cats are needed in the exhaust either..
http://www.zenoah.com/int/company/innovations/

[WilDun]

I haven't been here for a while and just checked out the Zenoah, it does seem pretty ordinary (despite the sales pitch!) but I know too that Zenoah is a well respected engine maker! I still haven't got my head around the carb/porting arrangement though (takes a while with me these days!).


I also would like to know a little more about this bike - I believe it to be a (pretty unusual) works 500 Jawa. I do remember Franta Stasny riding a similar works 350 in the sixties (or was it a 500?) - it had conventional teleforks though. The leading link arrangement may have improved the handling but it sure didn't do much in the prettyness department! ........ maybe someone can tell me more?

[/ATTACH]

[husaberg]

Posted for Flet


The V4 250