ESE's works engine tuner

[jamathi]

Don't talk to me about concrete; I just had lunch.

Now you're being modest. I bet you're the Head of Department.

A lot more manageable. The NSR500V riders I spoke to, all envied the speed of the Aprilia RSW500 but I bet that they would all be completely cured after one ride on it. 250 cc world champion Harada even bluntly refused to ride it after his first few outings. Only fearless Jeremy McWilliams seemed to enjoy wrestling with the beast.

Harada refused to ride it after the gearbox started to break down.
Not so strange, as it originally came from the 125...
After that a completely new engine was made.
Finally a full 500, but still short stroke
What a waste of time and money.....
Fuel injection was tried, everybody was happy with how it performed on the dyno.
On-track it proved useless however.

[peewee]

frits do you remember the hp and weight of the rsw500 engine? i had a idea of a inline twin of 500cc using the viper cylinders

[TZ350]

Fuel injection was tried, everybody was happy with how it performed on the dyno. On-track it proved useless however.

I am not finished yet but it's pretty much my own story so far. I can make good power but getting it ride-able is proving a bit of a challenge.

I would love to know more about the Aprillia EFI setup.

[F5 Dave]

Honing plated bores.


I’ve been reading an article from an ex engine reconditioner bestowing the virtues of diamond honing the plated barrel.
http://www.motoxparts.co.nz/tech/pro...-piston--rings





He claimed that the plated barrel should always be honed or the rings would not seal as well and wear quicker. Certainly on a steel bore I always used to hone or at least cross hatch scuff above the ports if in a rush.



He stated that the common “if you can see the hone marks” idea was flawed as the smaller edges as still worn off.


He warns against using ball hones & of course stone hones, but diamond hone machine costing many 10s of thousands.
Can't imagine anyone local having one.


On my 50 with plated bore the power used to go off as the ring wore. But it always seemed to some back to the same when a new ring was in place. 10 years on the power was down a little. I’d assumed that I’d just worn the plating oval. I bet a hone would have helped there.


I never bothered on my dirtbikes. Maybe scotchbrite and plenty of brake clean.



Wob etc, what is the sage advice?

[Grumph]

NZ Cylinders in Ashburton can certainly do a diamond hone. I've used them with good results.
More reconditioners are buying the gear as nicasil is becoming more common in cars now.
Ring around your area Dave, you may be surprised.

The setup costs per job are higher as apparently it has to be set up much more accurately than the old Sunnens.
I had a multi done and they told me the setup for that was nearly the same as for a single cylinder...

[Frits Overmars]

frits do you remember the hp and weight of the rsw500 engine?

Nope. Jan Thiel was decidedly not involved with the RSW500, so we have little solid information.

I would love to know more about the Aprillia EFI setup.

All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

[FastFred]

Fuel injection was tried, everybody was happy with how it performed on the dyno. On-track it proved useless however.

... pretty much my own story so far. I can make good power but getting it ride-able is proving a bit of a challenge.

Looks like you are in good company TeeZee.

[TZ350]

Might be the only time that I am anything close to being in the same league as the best .....

[Carel H]

Long time reader, admiring the sharing of knowledge here. In the fuel injection misery I want to add a thing or maybe two. Engines are made by mechanical engineers, ingnitions and fuel injection systems are programmed by software people. They leave you nothing but filling in parameters and guessing how they function internally.

A couple of years ago I made a CDI ignition just for fun. One of the things I encountered is acceleration. With just a trigger for ignition the only way to know the rpm is the last rpm, the last spark - the spark before that, but not the current rpm due to the acceleration on the current stroke. A single cylinder two stroke is the winner in this error. I solved this by measuring the rpm on the current up stroke and determine the spark advance after that. 15000 rpm = 250hz. A holiday season for the most modest microprocessors.

The mechanicals will say, why bother, the sparkies will say, overcomplex, but I found the numbers then interestingly enough to do it that way.

And off course I quit with motorcycles around that time, so no experience, just the observation here.

[2T Institute]

Only fearless Jeremy McWilliams seemed to enjoy wrestling with the beast.

I asked Jezza about that too "I would wheelie and spin the rear as soon as you touched the throttle mind corner" he said in that Northern Ireland brouge. He thought the 250 was the perfect bike. Jezza spends a few months a year in Australia including riding in 2 of the biggest classic meetings. A lovely bloke with some good stories

[TZ350]

All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

Thanks for the Aprilia injector position information.

... fuel injection systems are programmed by software people. They leave you nothing but filling in parameters and guessing how they function internally.

With just a trigger for ignition the only way to know the rpm is the last rpm, the last spark - the spark before that, but not the current rpm due to the acceleration on the current stroke.

Yes, I find I am guessing a lot about what the EFI software designer meant with some of their selective options. Interesting about determining the exact crank speed.

[jamathi]

Nope. Jan Thiel was decidedly not involved with the RSW500, so we have little solid information.

All I remember is that it had a big injector in each inlet tract and a small injector in each crankcase.

All the tests were done with a single cylinder engine,
And a 39mm carburetor, with a bigger carburetor the piston would melt in a couple of seconds....
The best power they saw was about 70HP I think.
The same injection was also tried on the 125.
Same HP as with a carburetor.
There was no injector in the crankcase.
I would have loved to have it on the 125!

[Tim Ey]

Yes, I find I am guessing a lot about what the EFI software designer meant with some of their selective options. Interesting about determining the exact crank speed.

Hence you got so much troubles getting to know what the Ecotronics designers wanted to do with some strange variables - why dont you give the ignijet injections a try? Their software seems quite easy and understandable.

[husaberg]

Yes, Jan would do a dual disc now.
Is it fair to say...? Well, yes and no. The RSA was an improvement over the side-disc RSW alright, but not by as much as Jan had hoped for.
But as the RSA was winning GPs, Aprilia-management decided not to spend any time and money on development; there may have been a few more horses in there, waiting to be unleashed.
You're right about the RSA250's rotation direction being reversed, compared to the RSW250. The various shafts in the engine were moved about in order to make it more compact. In the RSW the top crankshaft was driving the clutch; in the RSA it was the bottom crankshaft.
Left to right: RSW250, RSA250, RSA250.

I just figured out something was amiss with my musing......
The Aprilia has contra rotating cranks it wouldn't mater that the direction was reversed, as one would always be rotating the opposite anyway

[SwePatrick]

I´m having a thought.

Only proper way to get fuelinjection to work fully in a dynamic twostroke raceengine is to add a 3d map with rpm,throttle,airmass inputs.(map sensor won´t work)

As when pipe start doing it´s thing you have to predict fueldemand at fullthrottle without airmass meter, this makes it very off the chart in hitting the throttle again after a 'long' coastdown(pipe has gotten a bit cooler and doesn´t work 100% for a couple of moments until heat is up again)

Problem is the airmass meter unit, you need it close to the carb(to get fast reaction), and carb spits fuel the wrong way sometimes, this will lead to malfunction of airmass sensor.