30 replies to this topic

[f1steveuk]

Ok, I'll admit it, this is an argument settler!

The square four engine, more over in racing. In bikes, easy, RG500 RD500Lc, Aeriel and Healey, but cars!!?? Are there any racing cars that have been powered by non motorcycle derived square four configuration engines?

[Twin Window]

Wasn't there a single-seater series in the '80s (or whenever) which used the Alfasud engine?

An Italian domestic series IIRC.

[Catalina Park]

But an Alfa is not a square four, it is a flat four.
Now a Lancia is almost a square four, but not quite!

[ian senior]

Originally posted by Twin Window
Wasn't there a single-seater series in the '80s (or whenever) which used the Alfasud engine?

An Italian domestic series IIRC.

And one in France in the 70s that used the Citroen GS engine?

But do these qualify as "square fours"? I always think of the square 4 configuration as being as per the Ariel - i.e 4 upright cylinders set in a square, not the laying down flat 4/boxer type. But what do I know?

[Twin Window]

A quick rummage in my sticker box produced this...



I'm still uncertain of the period though.

EDIT: Ah, I hadn't realised that squares and flats were different...

I should know better than to opine on mechanical matters

[Catalina Park]

But if you had known what a square four was we wouldn't have seen the sticker!

A square four has two two cylinder engines side by side (or front and back!) with two crankshafts.

[britishtrident]

"Reversing" a square four used to be a hot topic in Motorcycle circles.

I had a workshop tutor at nautical college who had a Mk2 Arial Square Four, I Also had a mate who put a Mk1 Square Four engine into a Norton Featherbed frame.

[f1steveuk]

It could be the definition of a square four that will sink this argument!

The Lancia (Fulvia and Flavia) is technically a very narrow V4, and the Alfa a boxer, inthe sqaure four the cylinders are i think vertical, either geared to a common crank, or with two cranks geared together (my assumption!), and to be honest, I just cannot think of that many manufacturers that have gone that route, let alone raced them. They sort of lend themselves to two stroke, but four?!

[Catalina Park]

I can't think of any in cars.

[275 GTB-4]

Originally posted by Catalina Park
Now a Lancia is almost a square four, but not quite!

So is it a short or long stroker Mike Beautiful HF today just down the road from you

[britishtrident]

A square four is nothing like a narrow angle V4 (which is really an inline engine with cylinders at a slight angle covered by a single cylinder head) or a flat four (what is currently fashionable to call a boxer engine.

Think of a square four as a "U4" --- like a pair of Triumph vertical twin motorcycles engines with the cranks geared together -- which is in effect what the Arial Square 4 was (both designed by the same guy Edward Turner who later went on to pen the Daimler V8)

http://en.wikipedia....i/Edward_Turner


U Tube Ariel Sqare 4 http://uk.youtube.co...h?v=XoNG8FGh2ww

[r.atlos]

Gerhard Mitter's two-stroke F2 engine from 1965 would certainly be considered a "square four". Not a very successful one, though.

[fines]

Originally posted by britishtrident
A square four is nothing like a narrow angle V4 (which is really an inline engine with cylinders at a slight angle covered by a single cylinder head) or a flat four (what is currently fashionable to call a boxer engine.

Nothing to do with fashion - some flat engines are boxers, some not. Look up "crankshaft throw".

[Ray Bell]

There was a hillclimb car in Melbourne with what might well have been a square four engine...

I can't think of the name of the outboard engine that was adapted into that car, but I'm confident it was a 4-cyl of some odd configuration.

I have little doubt that Ariel Square Four engines have also been adapted into F3-like cars, particularly during the fifties and early sixties. Places like Pound Hill would have bred such things.

[Teapot]

Sidetracking just a little...isn't the term "square engine" also used for an engine with equal bore and stroke?

[2F-001]

Originally posted by Catalina Park
...A square four has two two cylinder engines side by side (or front and back!) with two crankshafts.

So a little bit like a BRM H-16?

[Yorgos]

Matra was developing a U8 Bagheera in 1973. I think that it did reach road-testing status but
the Yom Kippur war and the fuel crisis put an end to the project.
Yorgos

[Sharman]

Can't remember configuration but Jowett Jupiter?

[bradbury west]

Originally posted by Sharman
Can't remember configuration but Jowett Jupiter?

John, flat four
Roger

[Hoofhearted]

Originally posted by Teapot
Sidetracking just a little...isn't the term "square engine" also used for an engine with equal bore and stroke?

The square in "square four" refers to the cylinder layout. A square engine is equal bore and stroke.

[Arjan de Roos]

Originally posted by Twin Window
A quick rummage in my sticker box produced this...



I'm still uncertain of the period though.

EDIT: Ah, I hadn't realised that squares and flats were different...

I should know better than to opine on mechanical matters

OT1: I think the series ran from 1985 till 1994.

OT2: Also good excuse to post a pic from the Alfa museum.

[Hoofhearted]

Just out of curiosity could someone please tell me why on earth anyone would want to out an Ariel squre four into a race car? Or any car for that matter. Such a docile and weak motor would be a waste of time for racing.

[britishtrident]

Originally posted by 2F-001

So a little bit like a BRM H-16?

yep -- 1/4 of an H16, similar problems due to vibrations causing shock loads on the gears link the crank.

[britishtrident]

Originally posted by Hoofhearted
Just out of curiosity could someone please tell me why on earth anyone would want to out an Ariel squre four into a race car? Or any car for that matter. Such a docile and weak motor would be a waste of time for racing.

It was just a nice thing to behold like a traction engine or one of those little Mamond steam models.

To put it in context for anyone whoi hasn't seen one the closst modern equivaklent to the Ariel square 4 bike would be a Honda Gold Wing

[f1steveuk]

Originally posted by Hoofhearted
Just out of curiosity could someone please tell me why on earth anyone would want to out an Ariel squre four into a race car? Or any car for that matter. Such a docile and weak motor would be a waste of time for racing.

I didn't say an Ariel sqaure four into a car, I asked for a car, or better still a racing car with a sqaure four layout engine, the Ariel was mentioned simply to illustrate the layout.

[Allan Lupton]

The only reason for a square four that I can think of is that it is short enough to fit a motorcycle without compromising the wheelbase (as in FN straight-four) and narrow enough not to scrape the ground on corners as a six-cylinder across the frame Honda (or a flat-four/twin) might.
There seems little benefit to be had from the layout in its own right: geared-together crankshafts are never easy to use, the twin-cylinder engine halves have poor balance individually and not much better collectively, cooling the rear cylinders was not easy (liquid cooling would solve that, of course) and getting the inlet and exhaust ducts sorted out is a challenge.

[Macca]

Yes, there have been cars with square-four engines..............500cc class hillclimb Jedi cars using a tuned version of the road Suzuki RG500 2-stroke. Basically two twin-cylinder engines, one in front of the other, with a common crankcase, and the carbs mounted on the ends/sides of the crankcase breathing though disc valves, with the drive taken off the middle of both cranks which turn in opposite directions (two exhaust headers out of the front and two out of the back).......so with the smoother power (more bangs but smaller), adequately reliable.

I've probably got a photo of a Jedi somewhere, from Gurston Down.


Paul M

[Simpson RX1]

Originally posted by Allan Lupton
The only reason for a square four that I can think of is that it is short enough to fit a motorcycle without compromising the wheelbase (as in FN straight-four) and narrow enough not to scrape the ground on corners as a six-cylinder across the frame Honda (or a flat-four/twin) might.
There seems little benefit to be had from the layout in its own right: geared-together crankshafts are never easy to use, the twin-cylinder engine halves have poor balance individually and not much better collectively, cooling the rear cylinders was not easy (liquid cooling would solve that, of course) and getting the inlet and exhaust ducts sorted out is a challenge.

Actually, just about the only strong suit of the Squariel was it's smoothness; they set the cranks 90 degrees out of phase to give near perfect balance and for this reason it was favoured by the sidecar set, if it could be said to be in favour by anyone.

I've never ridden one, but one of my best pals had a couple in the early 60s and reckons they were like turbines, but heavy and unwieldy in every other respect; in fact, so unloved were they, his last one he picked up for a couple of quid and left in a hedge by the side of the A1 when it cooked a rear cylinder, it wasn't worth the effort to go back and get it!

Not quite the same story today though; apparently a non running and rather rough Mk2 4 piper went through auction at not far short of 5 grand recently, so start looking for those barn finds people........

Incidentally, to F1steve; the Yamaha RD500LC was a V4, only the Suzuki RG500 Gamma adopted the square layout, and lots of fun they were too!

[f1steveuk]

Originally posted by Simpson RX1

Incidentally, to F1steve; the Yamaha RD500LC was a V4, only the Suzuki RG500 Gamma adopted the square layout, and lots of fun they were too!

Yes. I need my ankles slapping for that one (could have been worse, I could have said NSR400, and that was a V3!!)

The reason I asked was an argument regarding multi cylinder engines and crankshaft strength, whcih went from V16 to W12 Napier engines, e.g 12 cylinders, but a crank the length of a four, it then got into H16s and thence on to sqaure fours. I am reletively sure no one has built a square four, specifically for a car, and not for racing, only converted bike engines?

[Allan Lupton]

Originally posted by Simpson RX1



Actually, just about the only strong suit of the Squariel was it's smoothness; they set the cranks 90 degrees out of phase to give near perfect balance and for this reason it was favoured by the sidecar set, if it could be said to be in favour by anyone.

I can't see that anything like perfect balance could be achieved, but it would feel better than a single or a parallel-twin which was otherwise the norm.
Setting the cranks at 90 degrees would give some interesting effects for both balance and firing interval.
What I can't recall is how the individual cranks were arranged (i.e. were they 180 degree or 90/270 degree) but whichever they were, they would need to be in phase to give equal firing intervals. Gearing them to rotate in opposite directions could give better mechanical balance.

Back to the point, Kenneth Neve built a twin squariel sprint car which I seem to remember has been resurrected recently by someone.

[Red Socks]

Originally posted by f1steveuk
It could be the definition of a square four that will sink this argument!

The Lancia (Fulvia and Flavia) is technically a very narrow V4, and the Alfa a boxer, inthe sqaure four the cylinders are i think vertical, either geared to a common crank, or with two cranks geared together (my assumption!), and to be honest, I just cannot think of that many manufacturers that have gone that route, let alone raced them. They sort of lend themselves to two stroke, but four?!

And the Lancia Lambda, Aprillia, Ardea and Appia!!