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Two-stroke Formula Junior (merged)


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#1 Bonde

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Posted 10 August 2006 - 00:29

One of British serviceman-in-Germany C. Scott-MacArthur's Saxon Formula Juniors graced The Copenhagen Historic Grand Prix 2006 in the Hands of its new China-domiciled Danish owner (motor racing is international if nothing else!). It was apparently one of the two cars he built, this one with a (now) DKW engine, bespoke frame, Triumph i.f.s. and VW rear. However, in the late and lamented Hodges' "A-Z", it is stated that this particular car had a BMC A-Series engine, and later the DKW. It also states that MacArthur's second Saxon was based on a Mackson F3, and it, too, had a DKW engine.

My questions are: Why did MacArthur switch to the more temperamental two-strokes? And why would the second car be Mackson 500cc F-3-based, when the first car seems so much more 'state of the Formula Junior art' ?

I'm intrigued that the Mackson-based car came before the 'bespoke' FJ second car and not vice-versa. Thoughts, anyone?

The Mackson-based car in 1960:
Posted Image
(Picture credit: formel3guide.com)

The existing (first?) car in Copenhagen 2006:
Posted Image

Unfortunately I only got to speak very briefly with the car's current owner (and I didn't carry my camera with me the whole time as I should have done in order to get some proper photos, but I'll try to chase more on this little-known Junior).

Does anyone on TNF know more about the Saxons or C. Scott-MacArthur?

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#2 JB Miltonian

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Posted 10 August 2006 - 04:31

Here is a picture of a Saxon Formula Junior, from "Sportscar Graphic", March-April 1960.

Posted Image

#3 Sharman

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Posted 10 August 2006 - 07:30

I do know why the DKW was so popular that a lot of people tried it even though there were always cooling problems with the centre pot in higher states of tune. Somewhere on another thread I commented that off the start Gerhard Mitter was able to outdrag everybody. So everyone else had to have a try, I think that the only person to ever win a well supported FJ race with a 2 stroke was Gerhard, fwd and all. Which says a) a lot for a his driving b) a lot for his engineering ability and mechanical sympathy

#4 Bonde

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Posted 10 August 2006 - 07:42

JB Miltonian,

Interesting picture, as it shows what is stated by Hodges as being the second car with a BMC A-series engine, whereas the picture from formel3guide.com shows the car with a DKW engine. This strengthens my suspicion that the Mackson-based car was perhaps actually Scott-MacArthurs first car, as it clearly had a change of engine, whereas the existing car does not bear any external signs of a change of powerplant and may well only ever have had a DKW - which doesn't fit Hodge's description of the first car.

Sharman,

I can understand the lure of two-stroke torque, and perhaps power, but I couldn't help comparing the change in British Elvas from two-stroke to four-stroke at about the same time. Scott-MacArthur would probably have had easier axcess to the DKWas he was apparently based in Germany - bringing over a Mackson chassis and a BMC engine doesn't to me appear to be the obvious thing to do in such circumstances.

#5 JB Miltonian

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Posted 10 August 2006 - 08:10

Here's another picture from Automobile Year #7, 1959-60.

Posted Image

#6 Bonde

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Posted 10 August 2006 - 08:29

Thanks again, JB!

Again - as the Mackson-based car was around in 1959 it strengthens my suspicion that the other 'bespoke' car is the second one and from 1960.

#7 Sharman

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Posted 10 August 2006 - 10:27

Anders
The Elvas STARTED with A series engines, don't forget that there were 2 classes in FJ, 1000 cc and 1100, the Fiats were running 1100's so there was always a search for more power. That was why things like linered Rootes engines were tried. The power unit had to come from a production car. In the early days there were no such things as XSP engines, they came later when BMC got involved. The manufacturers attitude in the UK was rather "can't be bothered", the tning which changed BMC's mind was the success of the 105E engine. Any way you look at it the "specials" were to my mind illegal and not in the spirit of the formula which was meant to provide cheap racing
John

#8 David McKinney

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Posted 10 August 2006 - 10:41

Originally posted by Sharman
The Elvas STARTED with A series engines, don't forget that there were 2 classes in FJ, 1000 cc and 1100,

Elvas started with DKW engines, though some owners had switched to BMC by the end of 1959
There was only one FJ class, though engines had a limit of 1000cc or 1100cc depending on a factor I've now forgotten - possibly 1000cc ohv or 1100cc side-valve

#9 Bonde

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Posted 10 August 2006 - 10:51

Thanks for the correction, John.

From the "Formula Junior Competition Cars" 'Motor' supplement of 1961 I got the impression that Elvas were 'born' with DKWs, or at least delivered concurrently with BMCs, which I had the impression was otherwise the 'original' British Junior engine. I have the (wrong?) impression that many surviving Elvas have been 'reconverted' to BMCs - or even Fords in place of original or 'second fitting' DKWs.

I agree that regulations allowed too far an extent of engine tuning, effectively pricing the formula to death. Formula Vee and Formula Ford showed later how it could be done. But aren't juniors just so appealing due to thier structural, aesthetic and motive diversity?

#10 Sharman

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Posted 10 August 2006 - 12:14

David
All the Stangs Volpinis Taraschis etc that I ever encountered were 1100 ohv. Maybe some French interpretation of the regs crept over the border!!
John

#11 Sharman

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Posted 10 August 2006 - 12:20

David
May I plead old age for missing out the most pertinent part of my reply, the restriction on classes was a weight restriction I can't exactly remember what it was
John

#12 Bonde

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Posted 10 August 2006 - 13:21

360kg minimum for 1000ccm, 400kg minimum for 1100ccm.

#13 David McKinney

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Posted 10 August 2006 - 14:04

Thanks Anders
(I didn't think the ohv/sv thing sounded quite right)

#14 Bonde

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Posted 10 August 2006 - 15:28

David, maybe you confused it with the ban on overhead cam shafts?

#15 RAP

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Posted 10 August 2006 - 15:29

[QUOTE]From the "Formula Junior Competition Cars" 'Motor' supplement of 1961 I got the impression that Elvas were 'born' with DKWs, or at least delivered concurrently with BMCs, which I had the impression was otherwise the 'original' British Junior engine. I have the (wrong?) impression that many surviving Elvas have been 'reconverted' to BMCs - or even Fords in place of original or 'second fitting' DKWs.[/QUOTE ]

Formula Juniors ran at The Brands Hatch meeting 3 August 1959. After a "false-start" earlier in the year, I think this was probably the first FJ race in the UK. Unfortunatly the programme does not specify the engine but the entries were
146 Elva Racing team (M McKee) Elva 1090cc dna
147 R W Thornton (Peter Pilsworth) Elva 948cc
148 Scott Bloor Elva 948cc
150 Ian Raby Moorland
151 K Zelenka Virgo 948cc
157 C Scott Macarthur Saxon 996cc

Clearly the 948cc cars were BMC powered. There is a write-up of the Elva in Autosport 1-1-60 which implies that the BMC engine is the standard offering. However at the Boxing Day Brands the works car was powered by the three cylinder Auto Union engine. Whilst not saying so directly, the report seems to imply this was an innovation. Incidentally the works tries a modified Hillman engine in October 1959!

The Scott Macarthur Saxon won at Brands 28 June 1959 in the first ever Monoposto Formula race. The programme for this saysit was BMC powered. There is a photo in the Autosport report of the meeting. It is clearly the Mackson-based car. In John Blunsden's 1961 book on F Junior he says that Scott Macarthur took the car to Solitude where he was impressed by the performance of the DKW engines and so fitted one for the following season.

#16 Bonde

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Posted 10 August 2006 - 15:31

Thanks, RAP.

A clearer, and interesting, picture is emerging.

I wonder what happened to the Mackson based car?

#17 David Birchall

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Posted 10 August 2006 - 19:04

Originally posted by Bonde
Thanks, RAP.

A clearer, and interesting, picture is emerging.

I wonder what happened to the Mackson based car?



An ex F3 based car turned up in Vancouver about 15 years ago that we identified as "probably" a Mackson. It had obviously been converted to a more 'conventional' engine but was very incomplete. i will try to track it down.
David B

#18 Bonde

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Posted 10 August 2006 - 19:42

The suspense is mounting!

It's interesting to note, BTW, that in the photos of the Mackson-based car, it is sporting the original Mackson front wheels when powered by the BMC, whereas with the DKW (Auto-Union), it's on wire front wheels, apparently of smaller diameter, but larger section. Either way, the front brakes look rather modest in size.

IIRC, the 'bespoke' car was on 13" pressed steel fronts (probably Standard-Triumph), and I strongly suspect that this car was never fitted wit a BMC engine.

Both cars have 15" VW rears.

I talked briefly with the Danish owner (of what I now believe to be the second car) who had just bought it in The Netherlands. He thought handling and brakes were OK, but he'd never really pressed it to the limit. The rear suspension has a lateral pushrod and bellcrank-operated interconnecting spring to force the back end to roll against its (too) high roll centre, the car is run with copious negative camber and to me it appeared steady and stiff on bumpy corners. With skinny tyres, a swing axle rear can be made to work - sort of... :|

#19 Sharman

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Posted 10 August 2006 - 20:14

In June this year I looked at another FJ, Dauphine derived, a Jordan. Reading your comment about swing axles reminds me that when I worked for Hertz we bought a company that ran rental cars in the North of England. On the fleet were 80 Dauphines. On a Monday morning we had an extra hand on the telephones to answer the calls from embarassed people saying" I'm afraid I've had a bit of an accident" to which the stock reply became " Oh yes sir/madam where did you roll the Dauphine....."

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#20 Sharman

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Posted 10 August 2006 - 20:59

I have just looked through FJ entries for 1958 and 1959, the first appearance of an Elva DKW is Boxing Day Brands 1959, on July 12 of 1959 came the first continental appearance of an Elva BMC (at the Ring). On that same day Scott Macarthur ran the Saxon DKW at Salerno. On July 19 Scott-Macarthur ran the SaxonDKW at Solitude, also entered by FITZWILLIAM was Chris Martyn in a Saxon BMC which did not arrive.

I think the ElvaDKW is a late comer to the scene and was not the original spec on offer

#21 Jan-Bart

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Posted 10 August 2006 - 21:00

Some pics of the Saxon can be found at www.racefotos.nl

Not so easy to navigate though.

Choose: auto's
then: Saxon form the drop-down menu
-alle evenementen- from the next dropdown
-alle series- from the next

Plenty of other interesting cars to see here as well.

#22 Sharman

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Posted 11 August 2006 - 08:28

I can now add that the DKW engines in the Elvas at Brands on Ice were different capacities and were supplied by Gerhard Mitter. Which I think removes any doubt about which came first and seems to confirm my first post on the subject as to why they were fitted.

#23 KJJ

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Posted 11 August 2006 - 22:47

Any biographical detail on Cyril Scott-MacArthur? Was he racing in the DDR in 57 and 58?

#24 bradbury west

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Posted 15 August 2006 - 14:53

Looking through an old Autosport with FJ stuff in it, I came across John Bolster's "Formula Junior Prospects" January 22 1960 , after the initial season in 1959, which included his comments on the AU/DKW engine as well as the perceived bhp of the period engines for the new season.


".............
Auto Union ...92 b.h.p.
Fiat ...80 b.h.p.
B.M.C. , .72 b.h.p.
Panhard ...70 b.h.p.
Ford ...70 b.h.p.
Renault ...62 b.h.p.

The Auto Union is a two-stroke, and it is very expensive to buy, simply because some engines will respond to tuning and others will not. One may spend £100 on tuning one of these engines and then have to throw it away. Another apparently identical example may take the tuning, and then you have a sure- fire race-winning proposition. So, a fully tuned German two-stroke will set you back about £425. However, there's another side to this two-stroke lark.

A Formula Junior car with one of these two-stroke engines will consume petrol at the rate of 7 m.p.g. That is immaterial in a Brands Hatch sprint, but long-distance races for F .J .s are a cer- tainty. As this fuel consumption is double that of a full Grand Prix car, obviously the weight penalty is prohibitive with a 792 lb. car, and pit stops will be the only answer. The Fiat engine is the: fastest four stroke so far, because it has an aluminium cylinder head, but as it is a full 1,100 c.c. unit, the higher' minimum weight scale is operative as compared with the usual 1,000 c.c. power plants. I doubt whether the B.M.C. engine will ever produce more than 75 b.h.p. "



I just thought it interesting.


Roger Lund.

#25 David Beard

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Posted 12 September 2006 - 20:47

Roger Lund sent me these snaps of the Mitter with its clothes off.
Three cylinders, three carbs, three coils: none of that surprises me.

Posted Image

But look at the exhaust: I’m sure I’ve never seen a racing two stroke that doesn’t have an expansion chamber for each cylinder. They are connected to a common manifold! That’s not the thing to do, surely?

Posted Image

#26 David M. Kane

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Posted 12 September 2006 - 22:35

Where might the "polar moment of inertia" lie with this car?

#27 Barry Boor

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Posted 13 September 2006 - 07:14

Just outside Dresden!

#28 bradbury west

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Posted 13 September 2006 - 08:12

Originally posted by David M. Kane
Where might the "polar moment of inertia" lie with this car?


I wondered the same thing, and was fascinated by the potential redefining of understeer. Looking at macca's picture, several posts above, of the car on the circuit, with the driver well amidships, plus the engine mass well froward of the axle line, it looks a problem. I could only get a shot of the rear end with the bodywork on, so I have no idea of the mass at the back.

Perhaps we should put this onto the Mitter Auto Union DKW thread.

A fascinating car nonetheless.

Roger Lund.

#29 ianselva

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Posted 13 September 2006 - 08:52

Originally posted by Alan Cox
Am I right in thinking that the yellow Ferrari Dino 206S (no 11 - the one with the stoved-in nose) in Andrew Kitson's selection of photos was also Carlos Monteverde? Is the chap just accident prone, or is this class of racing stretching him too far?

I seem to recall that he had a very nasty accident some years ago at a Coys Festival, in his Testa Rossa.

Didn't he also bend 3 corners of his 250LM at Goodwood in 2002 and then again at Oporto in 2005 along with his 250SWB ?

#30 Sharman

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Posted 13 September 2006 - 09:08

[QUOTE]Originally posted by David Beard
Roger Lund sent me these snaps of the Mitter with its clothes off.
Three cylinders, three carbs, three coils: none of that surprises me.

Posted Image

But look at the exhaust: I’m sure I’ve never seen a racing two stroke that doesn’t have an expansion chamber for each cylinder. They are connected to a common manifold! That’s not the thing to do, surely?[QUOTE]

[[/IMG][/URL]
[/QUOTE]URL=http://imageshack.us][IMG]http://img397.images...tterpipexe6.jpg

That is pretty much as I remember the exhaust arrangement in 1959 (and I don't believe the car changed the following year) save that I THEEEEEEENK that the expansion chamber was furthger downstream. It would be interesting to see how the system was applied to the Elvas (I've got memory loss there) and how Gerhard did it when he switched to his Lotus in 1961(?)

#31 Mark Godfrey

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Posted 14 September 2006 - 17:06

Goodwood 2006 - Renault F1 car plays national anthem
youtube.com

#32 David Birchall

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Posted 14 September 2006 - 17:26

Is that DKW engine thermo cooled?

#33 David Birchall

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Posted 14 September 2006 - 22:42

Roger Lund just sent me photos of the Mitter DKW which show the water pump on the lower left side of the engine--it looks like a Coventry Climax coolant pump but....

The reason for my interest in the DKW powered FJs is the the original BLT, as featured in Road & Track in 1960 was kicking around here in derelict form a few years ago and I wondered if it was worth doing anything with :blush:

#34 Bonde

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Posted 14 September 2006 - 23:08

David,

IIRC, DKW road cars were thermosyhon cooled - fairly easy to do with the radiator mounted just in front of the scuttle. On the Mitter FJ that couldn't work with radiator being so low and low-mounted - thus the pump.

I suppose the Mitter's polar moment wasn't quite catastrophic - those DKW engines were fairly light. I do suspect, however, that there was probably too much weight on the front, which would indicate inherent understeer. On the other hand, if using the DKW rear axle, the high roll centre at the back should help alliviate some of the understeer. Balancing the car on the throttle would have been next to impossible, I guess - but lifting off suddenly could have helped the tail around, assuming the free-wheeling function was deleted...oh well, I'm just rambling on about things I know little about.

David,

Whats the BLT?

Roger,

I dunno why, I just adore two-stroke Formula Juniors - especially the front engined, German variety.

#35 David M. Kane

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Posted 14 September 2006 - 23:18

That tube frame is pretty "light" looking...wouldn't want to smack anything. Any accident wouldn't be a quick fix!

#36 David Birchall

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Posted 15 September 2006 - 00:22

Originally posted by Bonde
David,
- but lifting off suddenly could have helped the tail around, assuming the free-wheeling function was deleted...oh well, I'm just rambling on about things I know little about.

David,

Whats the BLT?

Roger,

I dunno why, I just adore two-stroke Formula Juniors - especially the front engined, German variety.


Lifting off suddenly would probably put you into the nearest tree! :eek:

Having thought for a few minutes I recall it was the BLW. I really must remember to have a snack before posting....My stuff is all packed away, perhaps someone could scan and post a copy, couldn't they Vince?

#37 David Birchall

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Posted 15 September 2006 - 03:01

Rather than take up space in the Goodwood Revival thread I thought this was a better home for a picture of the BLW Formula Junior. The car, or one of it's offspring, was in Vancouver a few years ago in the care of a close friend (Dr Robert Follows) who passed it on. I identified it having studied the April 1969 Road & Track pretty thoroughly. It was basically derelict but fairly complete. I know nothing of it's history: Oh. and if some clever sod knows how to turn it over, please do so :blush:

Posted Image

#38 raceannouncer2003

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Posted 15 September 2006 - 03:38

Sure, David...

http://img246.images...9/blw329sh9.jpg

BTW, OT, the BLT was made by McDonalds...the BLW was made and raced by Bob Katke of Spokane...later, Bob built a radical short track car...see:

http://www.srv.net/~...website9084.htm

and

http://www.srv.net/~...website9093.htm

Is the BLW still "kicking around," David?

Vince H.

#39 David Birchall

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Posted 15 September 2006 - 03:46

Hi Vince, many thanks for posting that;-especially the right way up!

I 'think' I know where the BLW is now but will have to do some phoning around....

Of course, the BLW is now on two threads; this and the 'Saxon FJ' Thread

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#40 macoran

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Posted 15 September 2006 - 07:55

Posted Image

#41 Bonde

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Posted 15 September 2006 - 09:36

David (Kane!),

The Mitter frame was made from chrome molybdenum tubing so it would have been light, slightly stronger than it looks, quite flexible and probably a bitch to repair!

David (Birchall) and raceannouncer,

Thanks for posting the BLW picture - first time I've seen a picture of it. Some header tank it's got!

I'm sure the handling of the Mitter chassis left something to be desired, but wouldn't that apply to any FWD single seater? Even though Mitter won hillclimbs in it, his eventual defection to a Lotus chassis is telling...

BTW, does anyone recognize what make of chassis this car is ?: http://www.atspeedim...3/1960_dkw_fjr/

#42 Dutchy

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Posted 15 September 2006 - 09:50

It looks similar to the Souter-DKW currently campaigned in the UK

#43 Dutchy

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Posted 15 September 2006 - 09:58

I mean Sauter -DKW

#44 Bonde

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Posted 15 September 2006 - 10:59

Dutchy,

I don't think it's the Sauter-DKW: The Sauter has trailing link front suspension (VW or Porsche) - the car on Michael Plitkins site has double wishbones as well as differently proportioned bodywork.

#45 David McKinney

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Posted 15 September 2006 - 11:06

Dutchy only said it looked similar :lol:

#46 bradbury west

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Posted 15 September 2006 - 11:51

Cliff Davis American car feature at the Revival

Does anyone else think thast it was well done? I know that some TNFers turn up their noses at these Yank tanks, but I enjoyed the Chrysler feature last year, the cars this year were a good tribute, IMHO, to the old London spiv car trade, and intersesting in themselves. Broad church interest etc., things you would not normally see, all set out before you.

Any comments?

Roger Lund.

#47 Sharman

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Posted 15 September 2006 - 13:25

The junior looks like a fairly late car to me. Anybody have a picture of the AU-Bode?

#48 David Birchall

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Posted 15 September 2006 - 15:24

Thank you Marc, and that was the April 1960 issue of R&T of course.

#49 Twin Window

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Posted 16 September 2006 - 09:39

Anders suggested that merging the recent two-stroke FJ activity on the Revival thread and his C. Scott-McArthur Saxon-DKW thread might be a good idea, so that's what I've done.

If the thread title needs amending, please let me know!

:up:

#50 RA Historian

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Posted 05 October 2006 - 01:36

The DKW engine had a brief moment in the sun at Road America. The 1960 June Sprints F-Jr race was won by Steve Wendt in an Elva 100-DKW. Then in July there was a USAC 100 mile F-Jr race that was won by Curt Gonstead in an MBM-DKW. After that, hello BMC and Cosworth!

Also, Jim Hall won the FJ race accompanying the 1960 Sebring 12 Hrs in an Elva-DKW.