Leburg Honda alternator adapter

[JimCrawford]

I'd like to contact anybody who has fitted a Honda 600 alternator to the crankshaft of a VW engine, as described in the Leburg paprework. I have an adapter half made on the lathe and have got to the point where I want to cut the o-ring groove for the oil seal. I cannot reconcile either the dimensions or the seal given on the drawings to normal o-ring design practice. To my mind the design as drawn and annotated simply cannot work so I'd be interested to discover what others have done in this area.

Jim

[Chris Martyr]

Hi Jim,,,,,,and apologies as I have only just seen your post. Mind you , I'm not 100% sure that anything I'm going to say will help.
I was an early customer of David Mickleburgh and the flywheel adaptor/mount was not available when I received my drawings. The way I got round it was by using an old Type1 VW flywheel and asking a work colleague to machine it down to the hub.
I presume that the bit you're having trouble with is the recess on the inside of the hub that accommodates the 'O'-ring which pushes onto the back of the crankshaft. If you go to http://www.vwheritage.com the "O"-ring you need is P/N 311105283AGEN . Unfortunately , I cannot give you any dimensions as to how far in it sits and the dimensions of the recess , but if you could beg, steal or borrow an old VW flywheel for observation purposes then it will probably be slightly more obvious , or if you could blag an old copy of the Donald Peacock plans , surely the drive for the old Lucas mags came off the same hub and would have included the same "O"-ring set up.

I know that this is only tugging at straws Jim and I am sorry that I cannot offer a fellow LeBurg user more help. FWIW, I have just looked at my Haynes VW manual , which has a cutaway drawing of the crankshaft/flywheel assy. and that's pretty obscure as well.
Good luck,,,and please give us a progress report as I'm sure that it will resolve itself with a bit of good old fashioned LAA tenacity.

[JimCrawford]

Hi Chris,

Thanks for the information, I'll follow up the lead on the VW O-ring part number and see what I can discover. I do have a copy of the original Peacock drawings which show a cut down flywheel but the style used is that for a crankshaft that doesn't have and O-ring but uses a paper gasket at the end of the crankshaft. My other engine, in store for my Taylor Monoplane, also has this paper gasket - no O-ring arrangement. The paper gasket was only used on a small number of engines and I would guess that it may have been awkward to set the crankshaft end float as the gasket would compress as the crankshaft bolt is tightened.

Making the adapter from a billet has been an interesting exercise in it's own right (and I'm making three!) but I think the amount of fairly critical work is such that it would be rather easier to get a flywheel and cut it down.

Plan A at the moment is still to use a standard size O-ring and cut the groove to standard design rules, unless I get enlightenment about the standard VW arrangement.

I'm writing up this whole saga in great detail for the LAA mag. I should be submitting the first part, of a total of four, to Brian Hope before the end of March. Most of the work will be finished by then so it will be a more coherent write up than trying to document in real time as I'm constantly jumping between jobs on the lathe and making up the wiring looms and electronics as time and facilities permit.

Jim

[Chris Martyr]

Peacock drawings which show a cut down flywheel but the style used is that for a crankshaft that doesn't have and O-ring but uses a paper gasket at the end of the crankshaft.

Hope it doesn't sound like I am splitting hairs here Jim , but the "O"-ring is fitted inside the flywheel hub and not onto the crankshaft. It is very easy to remove a VW flywheel and not even see that there is an O-ring installed in the centre of the hub,,, [till you start it and it spits oil ]

Just to clear up a minor uncertainty, I have just been looking at VW Heritage's parts list and it looks like the pre-1960 engines didn't have this O-ring , so that maybe why you couldn't find one on your Taylor Mono. Jim and probably also explains why it didn't appear in the Peacock plans either.

Keep up the splendid work . The first hub will be the one that takes the time. The other two , you'll run off in no time,,,,,,,,,and I look forward to reading about your installation in the magazine.

[Bat Man]

Hello,

I'm just doing a Leburg conversion whilst restoring a VP1. I do wish I'd read this posting before I started work on the project. The manual does require some update and the best possible way to do this is though a really good write up in the LAA magazine. I wonder if you would be prepared to publish on this forum also?

Chris

[JimCrawford]

Hello Chris,

A timely posting. I've had to attend to family matters since last March and these have been of such intensity that I decided to stop all aviation activity until they were resolved - just to get some breathing space. All is pretty well sorted now and I restarted my VW/Leburg work a couple of weeks ago.

So the LAA mag articles are once more on the move. Publishing stuff on the forum isn't practical as the volume of text, drawings and photographs is far too great. I hope to load a superset of information and full resolution photos and drawings onto some sort of easily accessible webspace, possibly dropbox. It could also go onto the LAA DVD on VW conversions. I bought a copy at the last rally and found it contained the same documents as I had already collected over many years, at least I won't have to scan them now

The tasks in hand are the engine backplate layout, including the alternator arrangement and the Leburg parts, and the crankshaft adaptor. The latter is becoming quite character building as the three engines I have to convert could be different in this department: The Rollason Ardem is of an age when it could be either O ring or not, the Revmaster should have an O ring but the Revmaster flywheel clearly doesn't and the ex-RF4 engine has a different arrangement altogether so a bit of head scratching is in order! The first job, next week, will be to take the Ardem off the Nipper and remove the magneto system. I should then be able to find out what's at the back. I believe that a 'no O ring' plus gasket should work for all three.
Plan A is that the Ardem will live on the Nipper until the Revmaster has been converted with inverted oil and fuel. The Revmaster then goes on to the Nipper and the Ardem on to the Taylor Monoplane. The RF4 conversion remains as a swap out spare.

Jim

[Ripley]

Jim I have made a couple of adaptor so to take Honda alternators and have a grooving tool ground up to cut the o ring grove for a standard VW o ring let me have your email address and I can send u a picture or you could borrow the tool.

[JimCrawford]

That would be very helpful!

jimcrawford[DOT]oxford[AT]rocketmail[DOT]com should find me.

I recently bought a boring bar to cut the O ring groove but the one I was sent wasn't the same as the one in the brochure and couldn't be used. Apparently the manufacturers had changed the design, an unintended consequence was that it will not cut so close to the bottom of the recess. Please email me a photo and, if possible, then I would like to borrow the tool. It would save the work of having to make one.

Regards

Jim

[JimCrawford]

And another thing!

Does anybody have the crimping tool for the Molex connectors they would loan? The cheapest tool I can find is the RSonline one at ~ £150 (inc VAT) which is a tad steep for just a few connections.

Not only but also; can anybody tell me the exact format of the tacho pulse from the Leburg unit? I have acquired a very nice 270 degree movement meter which I want to use as a tacho indicator and need to design the associated electronics. Knowing what the input signal is would make that a lot easier.

Jim

[Ripley]

Jim where r u located , and telephone number ? RiP

[JimCrawford]

Oxford

0775 726 5030

Jim

[Ripley]

Did anyone see my question about successful tachometer that works with Leburg ?

[Chris Martyr]

Hi Robert,
That super sleek sex machine that you see in the top right of the page uses a Falcon T22-U-2R tachometer. I purchased mine from LAS back in 2003 and I believe they still do them....

[JohnLindsay]

Jim,

I have posted something that might be of interest to you in the Tachometer for Leburg thread but, from my old notes, the output from the Leburg tacho output is a trifle unusual – at 0 rpm, the tacho output is a continuous +2.5 Volts; at 1,000 rpm the output is a series of negative-going 4mS square wave pulses of amplitude 2.5 Volts i.e. down to 0 Volts, approximately 31 mS apart (equates to 2 pulses per revolution). I hope that helps!

Regards,

John.

[Ripley]

Good old Barry Smith , to the rescue again even in retirement.
The tachometer required for Leburg is a "Westach " model 2AT3-2 , seems only Westach themselves in the USA stock this !
Has anyone in the UK got a second hand spare , it looks like a normal Rotax / Skydrive type instrument with two pins , numbered 2and 5 but difference is it also can be recognised as it has a small loop of wire on the rear .
Any help before I wait 6 weeks for a US version to arrive ? Thanks RIP