ESE's works engine tuner

[peewee]

The engine is from a 1999 Honda CRM250 AR - the production version of their EXP-2 400 rally bike.

nice project you have going. is your assignment only to model the cylinder or do you have to prepare it for more power as well ? excuse me for not knowing but whats a crm250 ? I presume it was some kind of road going bike but is it medium or high performance ?

[jseb89]

Now all you need is an SLM (Selective Laser Melting) unit. Then you will have your cylinder directly in metal, no casting required any more
(minor problem: you will need a watercooled credit card).
Attachment 327730

Metal printing is very expensive and I think the material selection is limited, digital sand printing for casting is another option that is potentially cheaper and lets you have greater control of the material specification / composition - air cooled credit cards need not apply for either option unfortunately

[jseb89]

nice project you have going. is your assignment only to model the cylinder or do you have to prepare it for more power as well ? excuse me for not knowing but whats a crm250 ? I presume it was some kind of road going bike but is it medium or high performance ?

I'm not quite sure exactly what direction to go in yet but a good first step is to inspect, measure and model all of the components.

The basic composition is:

Bore & stroke: 66.4x72

Con rod length: 132.5mm (most modern 250's are 125mm)

Piston compression height: 33mm (most modern 250 engines are 38mm)

It's a road going trail bike, medium performance

[husaberg]

nice project you have going. is your assignment only to model the cylinder or do you have to prepare it for more power as well ? excuse me for not knowing but whats a crm250 ? I presume it was some kind of road going bike but is it medium or high performance ?

sorry the first ones fuzzy.
exp
https://www.kiwibiker.co.nz/forums/s...post1130353595

[peewee]

sorry the first ones fuzzy.
exp
https://www.kiwibiker.co.nz/forums/s...post1130353595

must be a european model as ive never seen or heard of it in the usa. looks interesting

[husaberg]

must be a european model as ive never seen or heard of it in the usa. looks interesting

More likely to see one in Japan, some were imported second hand all over the world though.

[adegnes]

Coming along!

[philou]

Many people complain about ignitech.
The power would be less than the original ignition on 250 rgv or rs honda.

It is necessary to couple the 2 outputs on a single coil for a cylinder, and to power the cdi with 16 V to arrive to equalize the original cdi.

Amazing that wobbly made with. What do we not understand?

[F5 Dave]

So how is this criticism manifested or quantified? Are you somehow measuring spark energy in a running system, or looking at a spark at turnover?

[wobbly]

The issue with the Ignitech in the case of the RGV ( Aprilia ) and the RS125 is that what no one realizes is the interaction between the output circuit
of a DC - DC converter and the ignition coils inductive reactance.
Both of those ignitions are DC-DC,like the Ignitech, but have been optimized to provide sufficient coil energy by fine tuning of the converter to drive the coils
primary resistance and overall inductance.
For the Ignitech, any coil can, and often is connected that is nowhere near correct to generate sufficient spark gap power.
The RS125 coil is very wrong, and doubling up the output circuits of a P2 ignition will then give better performance than the stock setup.
The RGV,Aprilia coils have worked perfectly well on dozens of race engine projects I have done.
But the Ignitech is also capable of driving huge power into a very high inductance ( with low resistance as well ) coil such as the big Crane CDI
versions.
This setup is ideal for high com methanol burning race engines,where big spark gap power is needed to fire off the rich mixtures reliably.
I now routinely use a P4 ignition on twins with circuits 1,3 and 2,4 paralleled into 2 RGV coils with very good results.
Edit - by that I mean way more spark energy than is actually needed.

[F5 Dave]

Just reading the Mike Sinclair book. Its not a literary masterpiece, but it is interesting and gives an interesting insight into some of the advances and some of the disadvantages of being beholden to a major manufacturer. Even with KRs considerable infulence as Team head and Marlboro money. Some of the advances made have been mentioned here, exh port bottom, carb solenoid, Czech university flow simulation tool etc.
Not sure if it will be available outside NZ.

I got loaned mine but I'll probably buy one for the sake of it.

http://www.batemanpublishing.co.nz/P...ProductId=1594

[Frits Overmars]

Jan Thiel just told me that he is considering selling a helmet that was given to him by Valentino Rossi in 1997,
the year that Rossi became a world champion for the first time. The helmet is signed by Rossi. Any takers?

[EssexNick]

Any idea how much he might be asking for it, or is it up for auction?
Two things I have to add, 1: Thank you for thinking of us. And 2: Unfortunately it won't be for me, but someone I know is a mega fan.

[wobbly]

Anyone got a Rotax 257 cylinder for sale.
I have an old engine that needs rebuilding and the cylinder is cracked on the spigot as many did.
A damaged one is fine as long as its serviceable.

[Frits Overmars]

Jan Thiel just told me that he is considering selling a helmet that was given to him by Valentino Rossi in 1997,
the year that Rossi became a world champion for the first time. The helmet is signed by Rossi. Any takers?

Any idea how much he might be asking for it, or is it up for auction?

I was only the messenger. You now know as much as I do and I am in no way involved, nor do I wish to be. Posting my message was just a kindness among friends.