ESE's works engine tuner

[FastFred]

More real than TopGear

[jonny quest]

Welding a crank is useless. Poor design is what causes crank to move. Even welded cranks move in a poor design

[husaberg]

Welding a crank is useless. Poor design is what causes crank to move. Even welded cranks move in a poor design

The crank on the Pulse/ROC/SwissAuto/MUZ 500 gp bike is a little special as its a flying web design.
When Fits said welded I wondered if he was referring to where the original Hirth joint was.

The unsupported disc between the cylinders is also the type of crank design as used in the SwissAuto V4 - Gp engine, that ended up as the Pulse 500 as run by some of the guys from the BSL500 team..This is called a flying web crank, but has the pins opposite to give 180* firing in adjacent cylinders.

One thing to note in the pics of the cylinder held by Thomas - the real RSA does not have any taper at all at the top of the duct divider ( septum), the end of the divider just has a small radius on each side.
This is to reduce the area ratio between the duct entry and the port exit.
Edit, here is a better pic I have just got.

That notch for timing reminds me of one of the cleverest triggering setups I have seen.
In the SwissAuto/Pulse flying web engine there were two magnets at 180* in one crank web with only 1 sensor, setup much as the pic of the RSA125.
I spent ages trying to figure out how it worked, untill one day I grabbed another magnet and discovered that each one inside the crank
was orientated N & S pole outward.
The trigger sensed the N pole as cylinders 1,3 and the S pole as 2,4, bloody clever and as simple as it could be made.

The SA500 engine was used in the Pulse and I rebuilt the one that Bill has when it first arrived in NZ..
Its cylinders did fire in pairs, and were very cleverly triggered by a N and S pole magnet embedded in a flywheel with a single trigger.
The pistons were A Kit Honda, with the domes machined off, leaving only the squish band radiused up from the timing edge.
Made them very light, but wow I thought the dome would sink for sure - never did.
Having a flying web only supported by a pin on each side of a flat plate in essence made for hideous stress levels and the only way the cranks would live
for any reasonable time was having them made in unbelievably expensive materials and processes.
They cost in the region of E20,000 each I believe, did 1500Km and then in the bin.

The reeds were very small in area and the carbs ( mag Keihins at E120,000 for 2 pairs ) were equivalent to a 35mm area, so the design was biased toward good acceleration, but it still made
close to 180 Hp at the sprocket.
The cylinders were very close in design to an A kit Honda, the big difference being the B port hook was a smooth radius, pointing to 1/3 across the piston to bore centre ( and of course SA on the side )
Again, all designed for mid power - I have some sitting on my bench if you want some pics , but nothing to see of interest really.

I have got access to one of the Team Roberts built, Mike Sinclair designed frames from the Pulse project and its an amazing piece of alloy artwork.

The code does not care about what part of the input is used to represent the duct/pipe, except to say that the duct temp is part of
the jigsaw as much as the pipe wall temp is.
Thus in this case we have an alloy spigot extension that has the slip joint around it, and water is a fair distance away.
I would opine that this alloy extension would be closer to the pipe temp than the duct wall temp, so should be considered part of the header.

Re the relative "betterness" of any one physical layout for a boat, in the case of the 4 cylinder the differences between say a twin crank
contra rotating stack ie a square 4 Vs an inline 4 Vs a V4 would all come down to the number of seals/bearings in total used to support
the flywheels.
As it would appear that balance, firing order and rotational precession have little bearing on the final result then FMEP would become important, except
maybe the inline 4 would have a much higher C of G and this may overcome any perceived frictional advantage.
Maybe the best compromise ( but problematic to implement reliably ) is a flying web setup.
Go buy a Swiss Auto, they were cheap enough in comparison to a Japanese factory engine at the time.

What you describe is exactly what SA Design did with the flying web V4 - 500, but needed no sealing between the crank pairs.
The Swiss Auto had adjacent cylinders crankpins running at 90* opposite each other off a common web that was sitting inside a common crankcase volume.
This eliminated a seal and bearing between those cylinder pairs.
Gave a very small package, but required very expensive materials, extensive FEA and heat treatment to overcome the stress levels generated in
the unsupported "flying web".

http://www.swissauto.com/d/motor/pro...Display=20000D

The SA didnt need to seal adjacent cylinders - they fired together off a common case volume.
ie the crank pins on each side of the flying web were displaced by 90*, as were the cylinder axes - thus both pistons arrived at TDC together.
Put two of these pairs in line and you have a V4 with the minimum seals/bearings.

I found the cost hidden in there 20000 euros and 1500km for the crank back in the day.
Conversely the Yamaha 500 cranks were 3000 pounds each (they have 2) in 1994
The recommended interval then was 1800km, Pretty sure the big bank cranks would have been half of that km though.

[2T Institute]

He was the one doing the beautiful RSA like Cylinders but alas his site seems to no longer have them or the other Honda conversion stuff.
he has this test bench listed but I can't figure it out .
http://www.he-ja.nl/winkel/werkbank/#

Wasn't just Thijs, the engine was designed by Mike Austin of Exaxctweld fame and Patrick Unger was to design the data aquisition. Jonas Folger was their rider, Patrick was Jack Millers engineer last year and is still working with Aki Ajo. Got knock on the head when.........."someone" convinced Gary Taylor and John Surtees that "his" design would be better. Any guesses on the name of that genius?

[husaberg]

Wasn't just Thijs, the engine was designed by Mike Austin of Exaxctweld fame and Patrick Unger was to design the data aquisition. Jonas Folger was their rider, Patrick was Jack Millers engineer last year and is still working with Aki Ajo. Got knock on the head when.........."someone" convinced Gary Taylor and John Surtees that "his" design would be better. Any guesses on the name of that genius?

I am picking it is something along the lines of Macbeth.................
I do try not to mention Macbeths name in Hope that the other Jan might post rather than just visit occasionally.

[jonny quest]

I mentioned it husaberg because so many people love to weld the crank pins on a perfectly good crank.

[jonny quest]

Has air ever been injected into a 2t pipe? Potentially raising temps at key rpm points?

[mr bucketracer]

I mentioned it husaberg because so many people love to weld the crank pins on a perfectly good crank.

only animals do that

[husaberg]

only animals do that

Mention husaberg that is...........

I have seen some stuff about using weld to secure Mallory. I assume its an overlap only securing technique to stop it falling out anyone?

The MUZ500

[gravmax88]

RGV250 cranks come with the center section welded from the Suzuki factory..............

[Frits Overmars]

my guess is that the end result between combustion and explosion for the same amount of fuel is the same amount of heat induced pressure...

Peak temperature during combustion is in excess of 2000°C. Aluminium melts at 660°C, so why doesn't the piston come dripping out of the exhaust? Because it is protected by the boundary layer of stationary gas that is clinging to all metal surfaces.
This boundary layer is an excellent heat insulator, but the shock waves caused by detonation can blow it away and once it is gone, there is much more heat transfer from the combustion gases to the metal, so the metal gets hotter and the heat-induced pressure will be less.

When Frits said welded I wondered if he was referring to where the original Hirth joint was.

By welded up crank he probably means that the crankpins are tig welded to the crank webs (flywheels) so that the crank doesn't go out of phase. It stops the "push" from one cylinder from turning the web on the crankpins, as the push is phased and hence not equal or at least not at the same time or 180 degrees apart. The weld only needs to be very small (not all the way around the crankpin) to ensure the pins don't turn.

That is exactly right Swarfie. I've seen welds where the crank pins were pressed into the flying webs (B), and in some cases also where they were pressed into the outer webs (A). The Hirth joints that made the Swissauto crank so expensive, were not welded.

[husaberg]

That is exactly right Swarfie. I've seen welds where the crank pins were pressed into the flying webs (B), and in some cases also where they were pressed into the outer webs (A). The Hirth joints that made the Swissauto crank so expensive, were not welded.

So zee Swiss could have learned a bit from zee Germans.
I guess in their defence it was because the Swiss designers were used to working with Cheese and Chocolates

The Konig crank (above) seems to be a better solution.
Anyone know how long it lasted. Yes I realise the HP was a bit lower then. It would be a bitch to make that way but it was how the Hondas twins were done so it must have been cheaper.

[Frits Overmars]

So zee Swiss could have learned a bit from zee Germans. I guess in their defence it was because the Swiss designers were used to working with Cheese and Chocolates.

Don't forget the cuckoo clocks.

The Konig crank (above) seems to be a better solution. Anyone know how long it lasted. Yes I realise the HP was a bit lower then. It would be a bitch to make that way but it was how the Hondas twins were done so it must have been cheaper.

What you are showing is not a König but a Konny crankshaft. Konny (http://www.konny.cz./) is a Czech company that started producing hard-to-get König parts, but their products are of higher quality than the original Berlin-made König parts.
I have little experience with the longeivity of König crankshafts in the boat engines for which they were designed, but their life expectancy in racing sidecars was not unlike that of a snowball in hell. The grip of a boat propeller seemed to be much more forgiving than the grip of a mile-wide sidecar slick on hot tarmac.

No Honda engine ever had a flying crank web; what they did have, was crank webs with one integrated crank pin each. It was not a cheap solution either, but it allowed the crank to be made narrower because per cylinder there was one less press fit that depended on length for rigidity.

[chrisc]

Excuse my ignorance but why do many of the 2 stroke cranks I see appear to have a cover on the web? Such as the crank above.

[husaberg]

Don't forget the cuckoo clocks.

What you are showing is not a König but a Konny crankshaft. Konny (http://www.konny.cz./) is a Czech company that started producing hard-to-get König parts, but their products are of higher quality than the original Berlin-made König parts.
I have little experience with the longeivity of König crankshafts in the boat engines for which they were designed, but their life expectancy in racing sidecars was not unlike that of a snowball in hell. The grip of a boat propeller seemed to be much more forgiving than the grip of a mile-wide sidecar slick on hot tarmac.

No Honda engine ever had a flying crank web; what they did have, was crank webs with one integrated crank pin each. It was not a cheap solution either, but it allowed the crank to be made narrower because per cylinder there was one less press fit that depended on length for rigidity.

I was meaning the integral crankpin but you missed the Honda that I would say was one of the bigger sellers i can't help but think Good ol Honda would have done it to save a few yen.
I can't see it being narrower because of it, they are problematic once the hardening starts to peel.Pretty sure most if not all early Honda twins were made the same way the cr93 were.

Yes I was cheating with the reproduction Konig I just assumed the design never changed.
I do have a pic of the original Konig Crank but not in bits though.