A VW for the 21st Century

ColinC · Post by **ColinC** » Sun Oct 04, 2009 10:47 pm

I was very interested to read Graham Clark's letter in the October issue of Light Aviation proposing that the LAA support a competition to promote the design of a 21st Century replacement for the long-running VW.

I think that this is exactly the sort of project that the LAA should be promoting in support of affordable and safe aviation.

If LAA Engineering could be persuaded to set out the requirements and specification of what would be required to meet the applicable regulations, I believe that the membership contains a number of very talented engineers who might be persuaded to rise to the challenge.

There are already a number of successful car conversions available. In the USA and other countries the Suzuki/GM engine range has produced some interesting engines and latterly the french Ecoyota (featured in October's LAA mag) is looking interesting.

Am I alone in the view that a design competition would be a good idea?

regards

Bill McCarthy · Post by **Bill McCarthy** » Mon Oct 05, 2009 7:04 am

A major element of such a challenge should be cost. Current "flat four " engines are beyond the means of most of the membership.

Ian Melville · Post by **Ian Melville** » Mon Oct 05, 2009 7:22 am

Hi Colin,
Not alone, but I think its a tall order to replace the VeeDub. There are a number of comercial engines out there that are on paper VW replacements be they fall down on cost. Millions of VW engines out there with a whole host of support/assesorys from all fields mean parts are cheap.
Add to the fact that very few people have the facilities to manufacture parts in the home workshop. Not exactly something you can do with a Black & Decker, and a band saw

Impossible? No. There must be engineering companies with spare capacity. All it needs is the ideas people to be paired with the engineers (I know of a model jet engine company that had parts made this way. The engineering company ran thier kit 24/7 to recoupe the millions it cost)

In the US, where the air is different they have Contact magazine for alternative powerplants http://www.contactmagazine.com/

Edit: see Bill had made the same cost point as I (did it realy take me 20 minute to type that

)

cardiffrob · Post by **cardiffrob** » Mon Oct 05, 2009 8:29 am

October mag? Grrrr. Not again!

Anyway, a major stumbling block has to be the ignition/carb situation for the VW. David "Leburg" was on the right track with this and Barry Smith was able to get a fuel injection kit for the VW. Surely it is time for a 3D mapped ECU kit for the venerable VW with Hall-effect ignition and a motorbike alternator? Add a reduction drive design that really works to take the prop loads off the crank nose bearing (plus allows a longer prop) and you must be getting there. An "all-in-one" bolt-on kit. Surely you can get the VW weight down with alloy pots and the power up to Jabiru levels? Bob Hoover (No, the other one) has some great mods for the VW on his HVX website.
http://users.lmi.net/~ryoung/Sonerai/HVX_Mods.html

I've got a wideband lambda kit installed so that I can calibrate the carb needle properly and the whole unit data-logs the performance of the engine as you run it. It will feed into an ECU if you want. Manufactured by Innovate. Works a treat on my 1952 sidevalve Morris Minor, so ought to work on an aeroengine that cannot be bolted onto a dyno.

Rod1 · Post by **Rod1** » Mon Oct 05, 2009 9:27 am

Do we really need to reinvent something? Why not take a look at what is currently available in the US and France and put some effort into getting UK approval for the engine and some engine mounting work? If the French have already got an industrial engine, modified it, flight tested it and put the mods into production for around £1k then why try to do the same from scratch?

Rod1

Colin - see you at strut tonight?

Nick Allen · Post by **Nick Allen** » Mon Oct 05, 2009 9:37 am

VW aero engine with reduction drive and fuel injection:
http://www.vw-engines.com/index.htm

Engine management kit for VW (car) engines:
http://www.johnmaherracing.co.uk/enginemanagement.htm

Ian Melville · Post by **Ian Melville** » Mon Oct 05, 2009 10:54 am

The bearing mention by Cardiffrob is one issue with the VW, the other is heat dissipation.
Though a Prop reduction drive is a nice Idea, it has implications for the airframe. Torque is higher, so airframes designed for the VW will need to reassessed.

Simon Clifton · Post by **Simon Clifton** » Mon Oct 05, 2009 11:02 am

The internal combustion engine is way past its sell by date.

I would expect the great and the good of the LAA membership, and the engineering executive, to be heavily researching electric motors and electric energy storage for LAA planes.

Forget about controlled explosions of flammable liquids, so last century.

Simon C
~~~~~~

Rob Swain · Post by **Rob Swain** » Mon Oct 05, 2009 11:12 am

Some of the listed alternatives at least get around the issue that we keep sticking the prop on the 'wrong' end of the VW engine.
Putting a prop on the end designed for the generator drive pulley and expecting it to perform acceptably with anything from 30 to 60 hp put though it is optimistic at best. The other end is where Ferdinand Porsche intended the main output power to be drawn from. However the cases, as designed, have a huge frontal area at this point for the bell housing / starter / gearbox to be attached.

I've long thought that the real solution is to make use of all the bits and pieces that the aftermarket air-cooled VW market can offer, but build all these things into a newly designed, aircraft oriented, crankcase.
Advantages would be:
crankshaft installed the 'right way' round
provision designed in for lightweight starter and alternator
provision designed in for electronic ignition / fuel injection
case would be designed to allow sufficient throw for longer stroke crankshafts, rather than having to have the already weak case machined out further for clearance
cases would be aluminium, rather than the light but problematic magnesium alloy of the normal VW
cases would be designed with small frontal area and a proper airflow over the cylinders for cooling
cases would be properly stressed and gussetted for use as an aircraft engine and with a suitable engine mount geometry
cases would be designed to have head / barrel studs intended for use with large bores (VW studs are uncomfortably close the edges of the barrel cut outs in the cases when big bores are used).
ancillaries such as the oil filler, oil cooler takeoffs and fuel pump can be located somewhere better suited to use as an aircraft engine.
bigger sump capacity
oil filter provision built in
provision for reduction drive built in, but optional and flexible (prop mounting either above or below the crankshaft).

I don't see that this as a particularly difficult engineering task, and I would imagine that the case could be hewn out of solid billets of aluminium by CNC machines (just like the Jabiru cases are).
I would expect (hope) the cost of the cases would be in the region of £600 to £1000 per engine. OK, this is about what it costs to build a basic aero VW at the moment, but I would see the resulting engine as an aircraft engine that happens to be built with car technology, not a car engine aero conversion. I'd be hoping for around 85-100 hp out of it too (when built as a 2180cc), rather than the 60hp of many (Peacock) conversions!

Of course once we've gone this far why not stick another cylinder between the front and rear, and supply the cases with a 6 cylinder crank and camshaft...

Bill McCarthy · Post by **Bill McCarthy** » Mon Oct 05, 2009 11:44 am

There are some gruesome examples of engine fairings fitted around VW engines. These range from flat face panels almost 2ft square behind the prop to huge bulbous affairs with little or no regard to aesthetics. Hub extensions can help but at the expense of weight. We had mentioned the BMW 1200S motor cycle engine with its claimed 120hp output (with the right engine management system fitted) as a suitable contender to the Rotax 912 series. The VW will no doubt be with us for a long time yet, - but if we could refine it still further...........

Nick Allen · Post by **Nick Allen** » Mon Oct 05, 2009 12:14 pm

....to be heavily researching electric motors and electric energy storage for LAA planes

What might be interesting would be a Prius-type drivetrain for an aircraft, with the take-off power coming from the supplementary electrical motor (i.e. the starter motor!): after all, we only need relatively small amounts of oomph to cruise...

cardiffrob · Post by **cardiffrob** » Mon Oct 05, 2009 12:30 pm

Wasn't there a company manufacturing new blocks for VW parts but with all the sensible mods? Something akin to the Porsche engine?

Nick Allen · Post by **Nick Allen** » Mon Oct 05, 2009 1:22 pm

Wasn't there a company manufacturing new blocks for VW parts but with all the sensible mods? Something akin to the Porsche engine?

Was is:
http://www.precisionalloy.com/pages/tf-1.html

Ian Melville · Post by **Ian Melville** » Mon Oct 05, 2009 1:59 pm

Nick Allen wrote:
....to be heavily researching electric motors and electric energy storage for LAA planes
What might be interesting would be a Prius-type drivetrain for an aircraft, with the take-off power coming from the supplementary electrical motor (i.e. the starter motor!): after all, we only need relatively small amounts of oomph to cruise...

Something like that has already been done. Was in all the mags a year or two ago. IIRC small piston engine driving prop with elecy motor attached.

Edit: Found it, though it was biggerthan I remembered. The concept is there http://www.avweb.com/eletter/archives/a ... tml#200862

Nick Allen · Post by **Nick Allen** » Mon Oct 05, 2009 2:38 pm

Ian, Ah, I remember that one now...but that system is somehow missing the point: there's no point lugging an extra electric motor plus associated drive into the air, when there's a perfectly good one, the starter, already strapped to, and driving, the engine! Then make the starter motor serve as the generator too...