Light Aircraft Association

During cold wet winter I have to dry out my SR4 magnetos with a hair drier before I can get my 1834 VW engine to start. (When we have nice warm summer weather this isn't a problem and the magnetos are fine, starting on the the first two or three prop. swings.) As our airstrip has no electric supply, it means I need to bring a very heavy generator from home to supply the hair drier. I'm therefore interested in changing to the Leburg system, which, I understand, is not so weather dependent and is approved for the VW engine in a VP-1.

Before I discuss with the LAA and Skycraft I would be grateful for a couple of bits of information from Leburg users-

1. Has the Leburg system a signal terminal for operating my Westach tachometer?
2. Does the kit come with mounting brackets etc.?
3. What is the procedure for approval of the installation of this system for my particular aircraft?
4. Presumably the mag. switches operate the Leburg in a similar way as with the magnetos.
5. Will I need to take the engine out to carry out the conversion?

Many thanks for any information.

Noel Howard.

Noel,

I wouldn't claim to be an expert but I did convert a VP-1 from SR4s to Leburg 3 years ago. I bought the system direct from Dave Mickleburgh and the current version from Skycraft is a little different.

In answer to your questions:

i) My system does indeed have an output for driving the Westach tacho.

ii) My kit came with all the metalwork and mounting brackets, plus the drawings, because my controllers are mounted on the rear of the crankcase and have to be accurately positioned close to the alternator rotor from which they receive their trigger pulses (done differently on the Skycraft version which has the triggering mechanism behind the prop).

iii) If you copy an installation that already exists on another VP-1 and has been approved by LAA Engineering, it is a pretty straightforward process. However, I chose to use 4 motorbike coils instead of the recognised Ford-type coils and made some other changes such that it became a new modification to a VP-1, meaning that I had to submit a Modification Application form with full details of what I was proposing to do.

iv) The 2 toggle switches operate in exactly the same way as mag switches but I couldn't use my orignal switches as one of them has to be a 2-pole switch. There's also a bit of a wiring loom to install.

v) I think you will have to remove the engine because you will need to install an alternator (in my case, off a Honda motorbike) on the rear of the crankshaft to charge the two sealed lead-acid batteries that power the controllers. Unless they have changed their minds, LAA Engineering would not accept a Leburg installation without a way of charging the batteries. Also, Engineering would rather that the batteries are not in the cockpit with the pilot. In my case, I had no room in the engine compartment and I was allowed to mount them on the firewall above my rudder pedals (which are not the standard VP-1 design).

I'm sure that Skycraft have most of the answers but if you would like to chat or see some photos, by all means PM me with your phone number. My aircraft is on a (waterlogged) strip near Chelmsford if you wish to look at it at any time.

Good luck if you choose to go ahead with the conversion. It cetainly makes for easy starting and removes any risk of the prop trying to bite you.

John.

Hi Noel,
Sorry mate, only just seen your post . But as a Volksplaner who runs an 1834ccVW with the incredible LeBurg system , I guess I may be of some help.
1. The tacho takes its supply from one of the ignition switches. One's a DPDT and the other's a DPST, it is the switch with the double throw that powers the tach. You will probably have to replace your current mag. switches with these.
2. As I was one of David Mickleburgh's early customers, there was no bracketry supplied at the time, only drawings, I believe that these days it may all be available, but even so , it's not too much of a challenge, as the biggest bit is the mounting plate made from 1/4 Dural [just make sure to get your PCDs right]
3. I believe that Francis' gang have given the system full approval for fitment to all VWs, subject to your Inspectors satisfaction that is. [please don't shoot me down if that's not correct]
4. You'll definitely have to pull the engine to carry out the installation .

The only bit that may need a bit of good old fashioned LAA savvy is fitting the alternator rotor to the machined down flywheel hub , although you may even be able to acquire one already machined.
I remember a few years back,reading of a a Tipsy Nipper being fitted with this system which packed up on its first flight, along with a partially seized engine . What I'm getting at here is ; make sure your crankshaft end-float is correct . The only problem here being that everyone tells you different figures . The Peacock plans don't agree with the Haynes Manual. Steve Bennet from Great Plains doesn't agree with either of them , I opted for VW guru Barry Smiths figure in the end .

[Cue Yorkshire accent] Anyone who tells yer more than 2 thou's lying .
Good luck mate,,it's definitely worth the effort !

Amazing , like London buses , You wait 2 days for a reply, then two come along within 5 minutes of each other.
Where do you live Noel ? If you can get down South East I will give you a guided tour of mine .

Only problem is we have a bloody great water feature in the middle of the airfield at the moment.
Called the runway,,,,,

I fitted a Leburg system to my Luton Minor during its major rebuild. The engine part was straightforward as I informed the LAA that this was exactly as per Leburg instructions. Only issues I had was to submit a minor mod detailing the location and mounting of the two batteries. In my case these are inside the cockpit and engineering insisted on sealed boxes to avoid acid spill on the pilot if a turn over accident occurs.

I was told that my engine/plane could take several hours to start on odd occasions on the old SR4's. In my ownership with this system and a Stromberg, starting is usually 4 blades to prime and then start first pull both summer and winter.

John Linsey (based in Essex) did a similar conversion to a VP1 about 2/3 years ago. He occasionally posts on here but I am sure will be happy to discuss or pass on details. If you contact me I can (with his permission) pass on his contact details.

Stuart Penfold

Stuart,

Noel and I have just made contact and discussed Leburg and VP-1s at length.

John.

P.S. I just wish my Solex carb arrangement started as well as your Stromberg seems to!

John, Sorry I spelt your name wrong!

Chris Martyr wrote:I was told that my engine/plane could take several hours to start on odd occasions on the old SR4's. In my ownership with this system and a Stromberg, starting is usually 4 blades to prime and then start first pull both summer and winter.

I knew writting this would cause me problems. Engine not run for nearly a month, yesterday It took 3 swings to start!

Start

I know what you mean.
It's a real pain with my old mags, after two months it took two swings

Quote: "It's a real pain with my old mags, after two months it took two swings"

Ditto Mike!

I run my 1834 up every month and the SR4s fire it up on the first or second swing.

Nowt wrong with them if they are set up right and everything else is spot on.

The only down side is if you overdo the priming and soak the plugs which is when the weak spark generated by an SR4 won't do the business.

I start on both mags rather than one just to give me the edge and so far so good!

There are more carp SR4 installations on VWs than there are good ones, and the number of good ones is decreasing all the time.

Sorry - it's just the way it is.

Anyway, Leburg ignition is fab. Fitted it to our old VP1, G-BAPP, as part of a total engine overhaul (kept the cases, crank, heads and canshaft and renewed pretty well everything else) and the beast started the first time on the first turn.
Fit it following the instructions / wiring diagram etc and you won't be disappointed.

It is better than any magneto arrangement (even Slicks) as it has programmed ignition timing.
For startup it will not spark until after top dead centre so it will not try to mash your fingers with a backfire.
Once started it advances the spark with rising engine speed so the engine always runs smoothly and will develop more power!

With the generator and batteries it provides, running radios and GPSs etc becomes a much less hit and miss affair!

Admittedly the system does weigh a little more than a pair of mags, but this includes the batteries as well. It does mean other batteries that are often fitted for running radios etc can be ditched.

Battery Location:
We fitted them in the cockpit, one either side, just ahead of the bulkhead for the main spar. They need restraining but don't need putting in boxes as they are fire / burglar alarn batteries and are fully sealed.
The seal is very reliable as when these are used in certain small computer UPS's their normal attitude is on their side!

Westach tacho:
Leburg ignition is wasted spark igniition. Basically a cylinder receives a timed spark at the top of every stroke, regardless of whether it is a power stroke or an exhaust one. This means the tacho reads double RPM.
Solution: Remember that funny loop of wire on the back of the tacho? Cut it and it halves the reading so it reads properly.

Hope that this adds something to the debate!