ESE's works engine tuner

[Kickaha]

Most extreme case i know of is Bugatti - he ran small dia tubes through the sump front to rear which were open to outside air. That would certainly increase the surface area available for heat transfer..

There used to be BMW deep sumps available for the Boxer twins with the same setup

[Flettner]

The begining of the water core ( master ), this will be the same mould for top and bottom half, sand cores glued together in the mould.
Core prints need to be added to hold the core in place as the metal is pored. These will end up being the water inlet ports.
These are what " frost plugs" are on a car engine, not actually for frost, they are there to hold the water jacket sand core in place as the metal is poored around it. Also allows gas to escape as the air in the core expands as the hot metal is surrounding the sand core.
Orange things are air gun pellets, gives me a standard thickness on curved surfaces.

[wax]

Thats so cool the casting and molds you are making. If you drew it could you not make the molds on a cnc router ??

[Frits Overmars]

Do the fins stick up into the gearbox oil on the inside? if they did this would greatly improve heat transfer.

Heat transfer from oil to metal is at least a hundredfold better than heat transfer from metal to air, so internal fins would not give much improvement. They would also make modelling and casting more complicated, so I don't expect you to find them on any production bike.

[Flettner]

EFI YZ250 at the Acerbis 4 hour two weeks ago. Wayne Blackwood at the controls.

[husaberg]

Neil i googled armourboard and only came up with it in weatherboard form where do you get yours?
moved on to bb's from the beads...... more masculine
looks bloody sweet btw.
Oh Frits what did you think of the YCAT transmission, Honda does one very similar for the new Dream/Wave
Honda CV-matic i can't read japanese but it looks like a wet clutch drive to me.(pics in english )

[RomeuPT]

Frits , Wob, if you can answer, I have a doubt.

The Aprilia RSA 125 102 pipe is a Ti pipe!? It has about 804mm of total lenght. This lenght is optimised for Ti or MildSteel?

Peaking at 13000rpm with 804mm raised the doubt, would the Aprilia engine gases had a clearly superior temp than the average 125 2t or would the Ti make the difference?

So, a mild steel pipe for Aprilia RSA would be around, 8% less or 739,68 mm total lenght?



Many Thanks

[Flettner]

Thats so cool the casting and molds you are making. If you drew it could you not make the molds on a cnc router ??

No problem, we have a three dimentional CNC milling machine in the workshop I could use, but I'm trying to show how to make a cylinder using basic tools, wood, bondi fill and casting resin.
We do most of our aircraft gearbox patterns on the CNC in amorboard.
I bought a pellet load of armorboard a few years ago, I'm not sure it's still available. The amorboard is good for machining with the CNC although it's important to use a vacume cleaner to keep the dust down while machining.
Wood is a good material to use for hand pattern construction. Best is kiln dried pine, I've just dissasembled two lounge chairs, plenty of dry wood in them.

Just thought I'd show ( picture above ) the YZ250 EFI still going about it's bussiness, a running testiment to twostroke EFI at work, it's done a few hours now.

[wax]

Ok that makes sense. Im really enjoying watching the work your doing on this cylinder casting. Keep up the good work. I have seen pics of your efi bike before. How do you find it holds its tune.

[Flettner]

Ok that makes sense. Im really enjoying watching the work your doing on this cylinder casting. Keep up the good work. I have seen pics of your efi bike before. How do you find it holds its tune.

We haven't needed to touch the tuning, it just keeps on doing the business, at between 14 - 20% less fuel burn over my standard YZ.
The original tuning was trouble free and within an hour we pretty much had the program that's in it now, ear and seat of the pants.
The reason it's so easy is because of the transfer port injection, each injection is a clean cycle with no residual fuel in the crank case.
Also because of what had been learn't with the Kawasaki F9 injection programe previously.
I'm just trying to point out to the doubters, that EFI on a two-stroke is practical.
We both suffered " incidents " ( hit tree roots ) in the race, it took me several miniutes to start my YZ as it lay on it's side ( as did I ) for a while and was flooded, but Wayne's EFI bike started first kick after it had been on it's side for a while, race winning advantage right there!

[Frits Overmars]

Frits what did you think of the YCAT transmission, Honda does one very similar for the new Dream/Wave
Honda CV-matic i can't read japanese but it looks like a wet clutch drive to me.(pics in english )

I hadn't seen either of them, but these pics look nice and compact compared to the usual scooter units. What kind of power, torque and revs is it supposed to handle?
(BTW, I think you're wrong: the pics are in dutch).

[Frits Overmars]

The Aprilia RSA 125 102 pipe is a Ti pipe? It has about 804mm of total lenght. This lenght is optimised for Ti or MildSteel?

Yes, it's a titanium pipe, like all Aprilia works pipes. But your second question amazed me. Can you think of anything on the RSA that was not optimized?

[Flettner]

What are the two rubber boots for sprouting from the top of the CVT case for? Cooling air perhaps?
I maintain the best system I've seen uses a chain with hollow boxes at each link set at 90 degrees to the chain travel. Many shim like parts are in these boxes and can slide, sidways. The chain wraps around similar drive wheels like the vairable rubber belts BUT the surfaces of these wheels have grooves, like key ways, running radialy out from the centre. The wheels are set so that if there is a groove on one side there will be a lump on the other exactly opposite. The shims then slide one way or the other depending on what they " see " . This makes for positive drive with NO slipage and can handle large loads at lowish speeds ( final drive perhaps ). System runs in oil.
Bekham plastic extruders used to use this system, small gearbox with high load and minimal heat generated.

[RomeuPT]

Yes, it's titanium pipe, like all Aprilia works pipes. But your second question amazed me. Can you think of anything on the RSA that was not optimized?

I have no doubt that every detail was state of the art, maybe I didn't write exacly what I mean.

I was just thinking about the 8% less lenght rule of thumb for Stainless or Ti pipes.

Thanks

[twotempi]

Neil i googled armourboard and only came up with it in weatherboard form where do you get yours?


I think "Armourboard" is a laminex group product and is essentially high density customboard.