Team-BHP - Horizontally-opposed engines: Reflections

Quote:

Originally Posted by RM2488 (Post 3202445)

Nothing is impossible- three cylinder inlines were common enough at one point- the venerable M800 having one.

Inline 3s came (back?) to the UK in the mid 90s, I think. A lot to be said for them. But I'd love to see your design for a boxer with 3 or 5 cylinders!

Quote:

Originally Posted by RM2488 (Post 3202445)

Regarding accessibility- I love the spacious engine bay in my Ikon. But practically every car on the market is so jam packed now- remove ten things for a single component. Although it probably makes the car more efficient, but difficult to work on for DIYers like me.

Couldn't agree more. They are becoming much more solid-state, and with very high labour costs in Europe many are scrapped well before they ought to be. Like you, I am lucky to be able to work on my own vehicles if necessary. I don't mind with really lovely machinery but everyday cars are a pain, one reason I use simple everyday cars with the W124 Mercedes and Golf diesels.

Quote:

Originally Posted by RM2488 (Post 3202445)

Looks like an evolved opposed piston engine. The "Commer Knocker" TS3 had an opposed piston with a gorgeous sound. Must look this one up.

Which, according to Wikipedia has a similarity with the pre-war Sulzer ZG9. Long time since I heard a TS3 knocker! Were/are there many in India?

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Originally Posted by Jeroen (Post 3200581)

Also, how do you figure out which piston is at its beginning of the piston stroke? Under normal operation the injection would have started already? So you need a few gadget and electronics to figure that out too. At least I assume the firing sequence to start an engine this way, is somehow of compared to the normal firing when running? (It's later, I assume?)

This has never been done so far AFAIK.

Mazda is the first to try and implement this and I believe it is in the market now (i-stop). They use precision speed/position sensors (resolver) along with stepper control of starter to bring the engine to a stop at desired position. Once that is accomplished, starting the engine is possible without cranking. However, this is only if the stop is < few minutes (stoplight) so that compression does not bleed off.
http://www.mazda.com/mazdaspirit/env/i-stop/

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Originally Posted by Mpower (Post 3202468)

Exactly what I said, without compression (and probably heat in the engine block) this is not going to work.

I'll see if I can get some more information on the Bosch system

Jeroen

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Originally Posted by RM2488 (Post 3202479)

Not that I'm aware of. I just read a lot. Too much probably.

I will try to reduce the length of my posts in that case, otherwise you may stop reading them altogether as has Sutripta! :eek:

I grew up with the sound of this weird engine but of course didn't realised what made the unusual sound. Engine and exhaust sounds were much more varied back in the 70s - there were loads of flat twins (bikes and cars), flat fours (Alfa, VW and Citroen) and Lancia's V4s to disrupt the sound of the straight four. Even the trains were all different, with turbocharged V12s (Paxman Valentas, as used in frigates and aircraft carriers) powering the faster ones. Today all the diesels sound very similar, gruff and boring.

I've just read the Suzuki triple will be powering the Caterham Seven shortly, with a turbo. Presumably for emissions reasons, although it should go well with the extra bonus of less weight.

edit - link found - http://translate.google.co.uk/transl...tor%2F&act=url

A very interesting thread - thank you flatout !
I think the word to describe the boxer engine is 'elegance'. Hats off to the guy who came up with this layout.
(reminds me of how an 8 year old Gauss figured out that the sum of first 'n' numbers equals n*(n+1)/2 => there are many ways to arrive at this, but none more elegant that just writing the series one below the other, one in reverse to the other )

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Originally Posted by venkyhere (Post 3206405)

From Wikipedia: "In engineering, a solution may be considered elegant if it uses a non-obvious method to produce a solution which is highly effective and simple. An elegant solution may solve multiple problems at once, especially problems not thought to be inter-related."

Inherent balance with much less vibration than an I4 or V6, a lighter, stiffer crankshaft, free revving, smooth across the rev range, a much lower centre of mass (with all the additional benefits for vehicle ride and handling) and much shorter in length.

Thanks for your positive comments venkyhere.