ABC Vee4 - new toy!

I had a school visit in Harpenden on Wednesday, so took the opportunity to drive on to Peterborough to collect the ABC Vee 4 I bought off E-bay on Tuesday night. It is a bare engine, although complete except for its magnetos (more of which later) but once formed the heart of a "power pod", an encased Auxiliary Power Unit used in Beverley aircraft for charging batteries etc whilst the main engines were not running. According to the loose leaf manual that accompanies it, it was taken out of service in 1958.

ABC engines are not common at the best of times and this Vee4 is the only one that I know of in private hands, although I understand Duxford have one in a more complete state. I've taken some pictures this morning, some of the engine itself and others from the manual, and you can see them at

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I love these aircraft APU's, the engineering is to the highest standard and the engineering solutions are s-o-o-o elegant.

I'm told that sometime in the last eight years, the previous owner but one removed the BTH magnetos, imagining that they might be used on a motorcycle. I need a brace of clockwise, flange-on-the-base mounted, BTH MC2 magnetos, preferably the S25 model, air ministry spec They are not going to be leaping off every table at Sodbury next weekend, are they? So if anyone has one (or two!), I'd be glad to hear from them. Base mounted magnetos off any flat twin (Petter, Norman, Coventry-Victor) will do fine.

Why does a pair of flat twin mags fit a vee 4? Because there is effectively only one crankpin - there are two separated by a centre main, but they are in line. So the crank throw is 360o, each pair of cylinders being offset in vertical plane, the rods being simply side-by-side on each crankpin. Therefore, if you visualise the engine not as two vee twins (as I did to start with!) but as a four cylinder engine with both pistons in one bank arriving at TDC together, it follows that one must be on the firing stroke and the other on exhaust. So, although it might be some little trouble to find them, at least I'm not looking for a pair of BTH mags with a firing angle of 90o!

Regards,

Kim Siddorn

Reply to
Kim Siddorn
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Kim is looking well on the way to a specialist collection of APU engines. This appears to be a rather neglected area of aviation history - if one goes looking for information on old aircraft on the WWW it is pretty rare to find any mention of the humble APU (try it for Ensign or Beverley). Do any of our aviation enthusiasts out there know when a source of electrical power other than batteries or generators on the main engines was first provided?

The ABC V4 is rather gorgeous, with all that black enamel it certainly puts one in mind of a shrunken aero engine - bet it'll sound good too!

Reply to
Nick H

Probably ties in with people such as ABC in this country and Homelite in the USA.

APU's went out of fashion for some reason, things like the civil DC6's for example had to have ground power units when standing and for starting, and I think the earlier things like DC3's had battery trollies.

Glenn D Angle's "Aerosphere" books are a good place to look for this sort of equipment, listing as they do the major engines, aircraft and aircraft parts suppliers.

I have a 1943 copy, I'll have a look over the weekend and see what I can find under APU's.

Peter

-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk

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Reply to
Prepair Ltd

Wow, looks a beast.

What HP rating / rpm do these have then? Do they have internal govenor or what?? Like the look of the twin carbs hung off the banks!

Tim..

Reply to
Tim (Remove NOSPAM.

Weight? How many extra passengers or bottles of G&T could you get on board if you dropped the APU? Only needed whilst on the ground and main engines not running so leave it behind...

Reply to
Dave Liquorice

It's 1942 actually...

D W Onan Lawrance Engineering & Research Eclipse (Bendix)

ABC are the only company listed in the UK section under auxiliary engines.

Peter

-- Peter & Rita Forbes Email Address: snipped-for-privacy@easynet.co.uk Web Pages for Engine Preservation:

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Reply to
Peter A Forbes

They are back in fashion now, the 747 400 has a 1,450hp one - next on Kim's shopping list I think ;-)

NHH

Reply to
Nick H

Last time this came up someone fora definition of APU. See:-

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Reply to
Nick H

Specs of ABC Bee Mk 100.

743cc Vee 4 (conceived as a vee4 and not as two "ganged together" vee twins.)

19bhp at 3,900 generating 28 volts at 200 amps.

Carbs, Solex 26VBN (handed)

Yes, they are governed and will spin up to 4,200 off load. Hence - I suspect - "as busy as a bee"!

Regards,

Kim Siddorn

Reply to
Kim Siddorn

Kim, talking about APU exotica, have you ever come across a Rotol unit?

Cheers Tom

Reply to
Tom

Waiting for some carb adjustment info from Nick on the Marconi-Stanley, I finally got around to removing the ABC from the back of the Volvo and making space for it in the workshop. Sounds easy, but it took three hours to clear enough space, stack stuff in a safe and sensible fashion and sweep up. I slid the engine out of the car and across the ali ramps (which I'm surprised to find are only two metres long, Peter !) and so into the workshop.

I'd prepared a cheap Workmate (£9.99 from B&Q) but the engine was too heavy for Hazel and I to lift that high, so I dug out the forklift sack trucks and they achieved the task with ease.

I had a pair of sturdy, rubber tyred steel disc wheels that I thought might turn the die-cast and machined aluminium subframe that the engine came on into a neat sack truck-type trolley and having removed the front lifting handle, they went straight on.

About two years ago, I'd bought some aircraft electrical kit, including a

200 amp 28 volt generator. The seven hole flange looked suspiciously like the one on the back of the vee4 - and it went straight on.

Well, damn me ...........

Not all good news because I need a splined bevel gear to actually drive it and getting hold of one may be a tad difficult - but it certainly looks the part.

Originally, the engine was cooled via a complex cowling that directed cooling air from the engine driven fan mounted under the rear bevel box. This is missing, fan included, so I've decided to mount two electric fans - such as one finds cooling car radiators - one under each bank blowing air up through the fins. This should be a cheap and unobtrusive solution.

Six new pictures (bottom of page one, top of page two) at

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Regards,

Kim Siddorn

Reply to
Kim Siddorn

Fascinating engine, just think of the cost of the casting patterns!

Shouldn't that 7-hole flange be 8-hole? :-))

I particularly liked the telegraphic address:

"REVS Walton on Thames" !

While not an engine that I would probably collect, it is indeed a good example of the difference between what we were doing in apu terms and what the USA was supplying.

Peter

-- Peter & Rita Forbes Email Address: snipped-for-privacy@easynet.co.uk Web Pages for Engine Preservation:

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Reply to
Peter A Forbes

was supplying.

Probably the same gene that attracted me to motorcycles since before I left school attracts me to this kind of engine. It's like being enamoured by this or that prospective sexual partner, its just as well we are not all turned on by the same things or we'd have all killed each other off long ago ;o)) !

This engine just about sums up ABC's perfectly. Why produce something simple when you can spend an absolute fortune and complicate the issue? A 750cc vee four to produce 19 BHP. Tush.

Their flat twin crankshaft is an absolute joy and about as elegant a solution to the slight imbalance brought on by having a boxer twin's barrels offset as could be imagined. There's a picture of one at the Webshots ABC album. I dread to think what it must have cost to make. How the company survived so long, I cannot imagine.

I was struck by the Ranger APU fitted to some later B17's and on into B29's. The simple Homelite twostroke has been superseded by a wide angle vee twin that is very similar to ABC practice.

Regards,

Kim Siddorn

Reply to
Kim Siddorn

Rotol? No, Tom, I didn't know they did one. I know them in a motorcycle context, of course, but not in APU terms.

What sort of things do they make?

Regards,

Kim Siddorn

Reply to
Kim Siddorn

Well Rotol were airscrew manufacturers, perhaps they saw the need for diversification with the advent of the jet engine, as they started making APUs in 1945..

The P-6 was a horizontally opposed air-cooled, 6 cylinder sleeve valve engine.

Bore & stroke of 3-3/8" x 3", 2.6 lit.

96 hp @ 4250 rpm max 60 hp @ 3750 rpm normal

32 kw 110v AC & 4.8 kw 29v DC overload

20 kw 110v AC & 3.0 kw 29v DC continuous.

550 lb complete.

The one that tickles me is the Eclipse-Pioneer 4 cylinder HO that was supercharged with a roots blower, all for 30 hp @ 4000 rpm. 71 CI. They also made a blown 2 cylinder HO engine too.

Tom

Reply to
Tom

I've been doing some trawling on the Web this afternoon and am drawing to the reluctant conclusion that if there is anyone that knows more than me about ABC APU's out there, they are keeping very schtum about it! I am now thinking that I ought to make some webpages setting out what I've learned over the last couple of years in the hope that someone - anyone - who worked on, with or by these engines can add to the very thin layer of knowledge I have. There must surely be people still alive who remember these things?

After an hour of searching, I found this single paragraph on a German website.

"During the First World War the company manufactured mainly aircraft engines, which were designed by chief engineer Granville Bradshaw. From this development one already began during the war with the production of APU's and sold current supplies on the basis of small double-piston engines. The first employment of an APU took place in the Supermarine Night Hawk, where an aggregate of ABC of engine supplied a headlight with 5 HP of achievement."

Thing is, I've never constructed a website before. What do I do gentlemen?

Regards,

Kim Siddorn

Reply to
Kim Siddorn

Website is a good idea, but SEM would be ever so pleased to see a nice article on early APU's in general (I intimated to Pat Knight that such might be forthcoming when I passed his tip Re availability of M-S engine on to you).

I take it you have read the ABC article(s?) which appeared in SEM some years ago.

Reply to
Nick H

"Kim Siddorn" wrote (snip):-

Googling Mr. Bradshaw is quite interesting - nothing on APU's but the Sopwith 'AT' sounds fascinating! (Of course Sopwith later built ABC motorcycles)

Now that really *must* be the first APU! (1915 Zeppelin night interceptor).

Reply to
Nick H

I thought I'd make up a petrol tank for the Vee 4. I picked up a reasonable cylindrical tank with recessed ends and a junk metal cap at Cheddar on Saturday and thought it would do nicely. There is a flat section with four tapped holes on the rear upper face of the crankcase and I made up a bracket to fit these, making up a couple of round posts from old cycle frame tubing to support the tank off the bracket. I brazed these up without problems.

Turning to the tank, I removed all the paint with a brass cup brush - and discovered the base was peppered with small rust holes. If common sense had prevailed, I'd have stopped there and found an alternative at the Sortout, but no, having got this far I chased the holes down one by one, ever more appearing as I flooded the area with braze. Finally, I brazed a plate over the worst offenders attached the mounting plate, cleaned it up and primered it. Took all afternoon ....

I spent some time considering the cooling problem but after revolving various ideas, reverted to the two electric cooling fans under the cylinder banks. They need to be about six inches across and the flatter the motor the better. Anyone got anything about like that or recognise a suitable car component?

Regards,

Kim Siddorn

Reply to
Kim Siddorn

A new thing has aris to bite me. Turning the engine over this evening, I noticed that the two magneto drives revolve in opposite directions, so I need a clockwise AND anticlock magneto. I thought I was doing OK, too .......

At the moment, I have little real evidence except the generally un-knocked about appearance, the pristine condition of the flats of every single nut and bolt, the rich golden colour of the oil and the obviously original wire locking on every important nut and bolt, but I think this engine is brand new and has seen test use only.

It is s-o-o-o complicated: I wonder what they cost new?

Regards,

Kim Siddorn

Reply to
Kim Siddorn

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