Oddball engines and prototypes

[Pursang]

Tyrrell did watercooled brakes in F1 years ago, not because the brakes needed cooling, but because they could dump a whole lot of weight as soon as the race started. Cars had to be weighed after the race, but regs allowed that they could be topped up with consumed fluids before weighing.

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'.

[Pursang]

Daryl, I realise that I probably don't know a helluva lot really (doesn't stop me thinking or talking though).... but it appears that with HCCI, there is no spark plug needed to initiate combustion,(at least in the running mode, as opposed to starting mode which may require a spark). So there is not actually any flame front, combustion is instantaneous. When it has reached the correct temperature and pressure, it ignites (all through the chamber) and does not have to spread, as it would do in a normal engine, so possibly there doesn't need to be a "trench" to conduct it across to the other side. That's my thinking but maybe someone else can veryify that for me.

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.

[husaberg]

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.

I Have posted stuff about the KR harleys before somewhere, they took what ricardo found 30 years before and made a better lemon.
The other advantage at the time was their valves didn;t get tangled and they had near direct valve actuation

[WilDun]

There you go, and I thought I knew it all!
Must say that as far as being able to take huge forces is concerned, I'd go for the Victa before the B&S!- but then, like the old Harleys, the B&S plodded on forever without actually making any progress in the performance department, bringing in a steady income by just doing......... nothing!

[Pursang]

I Have posted stuff about the KR harleys before somewhere, they took what ricardo found 30 years before and made a better lemon.
The other advantage at the time was their valves didn;t get tangled and they had near direct valve actuation

The other "advantage" they introduced was having the Rules written to ensure that it was almost impossible for any other manufacturer, with better technology, to be competitive in the premier class. (from 1946 to 1963, when Dick Mann won on a trick, fast 500cc BSA single).

Happened back in the 30's too. After the board tracks finished up, 350 & 500cc speedway & long-track was quite huge in the States, 'til the depression.

Croker had the really smick bikes, HD & Indian had factory teams competing all over the country on speedways and horse racing tracks.

With the depression hurting sales, HD & Indian decided they would sell more V-twin production bikes, if that's what the people saw racing.
Had the rules written how they wanted, killed off the trick, fast 500 singles. Bugger all M/C speedway in the USA, til the 70's.

In Oz, NZ, Britain & parts of Europe, 500cc singles were the premium models and speedway continued.

Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.

Cheers, Daryl

PS. I actually love what American flat track racing eventually evolved into, er! 450 singles,
but imagine them trying to catch a Bultaco Astro with a modern technology 2 stroke engine (2T's were banned in 1987).

[Michael Moore]

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'.

That depends on how they write the rules. Some organizations say "everything not specifically allowed is prohibited" while others are of a style of "if not specifically prohibited it is allowed."

[guyhockley]

He had help
Attachment 331578

So now my browsing history shows I looked at a picture called "Pussy tuning"...

[Frits Overmars]

That depends on how they write the rules. Some organizations say "everything not specifically allowed is prohibited".

Yeah, those are the rules where you are not allowed to inflate your tires because that's not in the book.

Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.

Come on Dary, you know you can do it if you try.

[Niels Abildgaard]

This might be the problem, the SV squish does a few important things:

A) It pushes the mixture across into the valve/combustion chamber.

B) It attempts to produce a "reasonable" Compression Ratio.
(really hard to do Hi Comp. & maintain decent intake flow at the same time)

C) Creates a sudden lower pressure zone above it, as it heads south.

D) It keeps the top of the piston cool, by:
a) pushing away the warming (by compression) mixture and:
b) by close proximity to the cool head surface and;
c) By shielding the piston from the main combustion.
d) C) above.

And that's the rub, the gasses trapped above the piston are way cooler than those in the chamber and might not be able to ignite at the same time.

I know a little about SV engines.....But I truly know nothing of HCCI.

Plenty of scope for experimentation though, test engines are plentiful and cheap. Bit like Victas.

Cheers, Daryl.

Make it a two stroke HCCI SV and nobody knows anything.

http://i.imgur.com/Iz3tD97.jpg

or even more useless:A two stroke Harley

http://i.imgur.com/kgeUWsJ.jpg

[WilDun]

The other "advantage" they introduced was having the Rules written to ensure that it was almost impossible for any other manufacturer, with better technology, to be competitive in the premier class. ...........Hard to imagine that a manufacturer could have "the rules" changed in order to promote only the type of motorcycles they produce & sell.

Honda, Dorna, MotoGP.

PS. I actually love what American flat track racing eventually evolved into, er! 450 singles,
but imagine them trying to catch a Bultaco Astro with a modern technology 2 stroke engine (2T's were banned in 1987).

Honda again?

But ....... to show that I'm not biased in any way, I have an old Honda CRV car which rattles along nicely! (and it's not a two stroke!).

[WilDun]

Make it a two stroke HCCI SV and nobody knows anything.

Yes, well maybe I'll have to rewind and think it over!

or even more useless:A two stroke Harley

That'd be like when the Gods came to earth and mixed with mankind! - Look what happened after that! - God forbid!

[Grumph]

It always pays to Read the Rules Very Carefully. As Smokey Yunick said (and lived and raced), 'It's not cheating unless they actually say you can't do it'.

Ron Grant is said to have had that up on the wall in the Honda Britain workshop - where they cut and welded a VFR750 crank to change the firing order...In "Superstocks"....

I've lived by it too - which has resulted in some, "interesting discussions," with officialdom over the years, LOL.

One of my old friends - now dead - was on the CIK Commission as the rep from this part of the world. I always had him on about the CIK rules being of the type where you couldn't do it unless they said you could...He'd agree, then go away to find a way of tightening the rules further...

[WilDun]

Yeah, those are the rules where you are not allowed to inflate your tires because that's not in the book.

Those who religiously follow the rules hinder evolution, those who defy the rules progress (or die).

Come on Dary, you know you can do it if you try.

Like the Victa and the Harley it's Iron! (and the world's best selling motorcycle!).

[Pursang]

Does that mean that you have seen the light and are switching to watercooling Daryl? In that case the good news is that you don't need 60 litres per minute; the rule of thumb is one litre per crankshaft-HP per minute. .

As a gesture to Common Sense, the Laws of Thermodynamics, and out of respect for Great Advice, given warmly and freely.......

...AND.... In the absence of Any Rules that dictate otherwise.. The Victa will be Water-cooled!!!

I've spent some time on this and think I have something reasonably practical, that I can turn up at home, from a 50mm length of 120mm diam. aluminium billet.


It's not perfect, and somebody might say: "I'd rather say they had a water cooled head cover. Coolant in the cylinder was hardly moving; cooling below the exhaust was non-existent. Not the best solution if you want reliable power." or something like that.

It will be no harder than casting and machining a decent air cooled one.
It will reduce the air cooling requirement, (or at least transport a fair percentage of it to a radiator).

A water-cooled exhaust duct will be a much tougher fabrication.

Transfers (whatever they'll look like) can hang in the breeze, for now.

cheers, Daryl

[Grumph]

Google "Dent water cooled conversion" Daryl. I can't post a link sorry - but it's in a vintage kart club site.
Similar to what you're doing but the alloy pipe seats on the lowest fin left on the barrel - and the head is air cooled.
As someone will say - it looks like sitting the barrel in a bucket of water - but it worked.
There's no sin in leaving the head air cooled - MZ's were like that for quite a while.