ESE's works engine tuner

[husaberg]

Aaron Slight???

I had that argument once, but it wasn' t him.

Husa - I think you may be wrong about the KR250 winning a NZ title. I suspect you're getting mixed up with the KR1 S specials produced by Boyles - and a page added to the manual to aid homologation, LOL.

There have been a couple of KR250's modified for local club racing, neither very seriously as parts are a concern. Frits may be amused to learn that invariably the first thing done is to re-phase the cranks. Both the modified ones I know of are now parked up permanently.
I also know of one still on the road which has also been re-phased. More because it simplifies the ignition once the original fails.

I have it in a mag here
It was the season that ended with the Snydham GP it was def the tandem
I am not sure if it ran the whole championship though on it though he may have started on a RZ250 then finished on the KR250.
Yeah the Boyles change bits is legal as long as you do the min number thick, If it was good enough for the Wire wheel black pipe Katana, it was good enough for Kawaski as well.

Nah, I don't think so. The shock absorbers were built into the hub of each primary gear, see below left. They were of the cam-type, with spring-loaded lateral movement, like you'll find in a number of British Torrey Canyon-type engines (below right).
The Kawa clutch hub would only contain some springing that pushes the driven gear and the anti-backlash gear against one another, like on the six-pot Honda CBX1000.

I should have googled the parts fiche.
Looks like you are 100% Frits, it has a Old pomy like crank shock interlocking cam shock absorber, but with a beville washer set up as a spring.
there is indeed also a rubber damper in the clutch sandwiched with a plate.
Later models also had rubber dampers in the disk valve.
http://www.kr250.org/KR_partsbook.htm

I had never seen that the Kawasaki engine had both an intake by disc and valves.
I was very interested in this engine, but so far I had not found much information

They called it Krris which is Kawasaki reed rotary induction system.
I wouldn't lose sleep over it, As it wasn't for top end power
Pretty sure the AR125 had the same system which Europe did get in numbers?

if you look where screw 92009 is you can see the reed valve
here is some info

if you look at 1.02 you will see it


http://twwhlspls.com/tandem-twin/
http://www.kr250.org/KR_home.htm

[jasonu]

I had that argument once, but it wasn' t him.

.

Eddie Kattenburg perhaps.

[husaberg]

Eddie Kattenburg perhaps.

Just for giggles aussie

[Flettner]

Husaberg, the last hoorah for the rotary valve.
What a pity dumbarse Kawasaki gave up on the RV and just followed the others with reeds, never to do any good again with the twostroke, dickheads.

The Gibs experiment on my 360 is a testing vehicle for the RV to be revived, and set into the 700 V twin, variable rotary valve induction engine. Tractability of the reed down low with the all out power of the RV top end.
That's the trouble with RV engines, if you want hard out top end RV timing they are all but unrideable off the pipe.
But who am I to say, you all know this anyway.
Love that video though.

[F5 Dave]

You forget how far road tyres have come. Not much lean angle going on there.

[husaberg]

Husaberg, the last hoorah for the rotary valve.
What a pity dumbarse Kawasaki gave up on the RV and just followed the others with reeds, never to do any good again with the twostroke, dickheads.

The Gibs experiment on my 360 is a testing vehicle for the RV to be revived, and set into the 700 V twin, variable rotary valve induction engine. Tractability of the reed down low with the all out power of the RV top end.
That's the trouble with RV engines, if you want hard out top end RV timing they are all but unrideable off the pipe.
But who am I to say, you all know this anyway.
Love that video though.

I was reading the other day about the OW60 that Croz rode which was the Yamaha copy of the RG500.
It was dyno'ed 156HP Rear Wheel in 1983.
This was a massive increase over the Inline 4 piston port OW48R Yamaha previously had. and a huge decrease in weight over the first square 4 OW54
Kenny only rode it in a few races opting for the Rotary valve V4 the the rotary valves inside the V. The OW61.
The Yamaha mechanics claimed the OW61 it was the worst bike Yamaha ever made. Likely cost Kenny the championship.

Croz on the other hand only had access to the older OW60 in the AGO team. He rode the bike and realised that something was really wrong in the front end so with Yamaha permission Radar hacked off the steering head to get rid of the funny geometry Kenny had built in and set it up the same as a RG500.
He loved it then. It was 2 seconds a lap faster than it was previously.
Although Croz finished second it could have gone better, The story goes that Radar Cullen and Croz and the other mechanics would build a bike only to come back and find Ago had lent it out to an Italian for a local meeting and it would be broken crashed or out of spares right before the next GP. Yet he still finished second in the championship. Kenny finished 4th.
What I never knew was the Yamaha OW60 was triple port with a PV.
I linked the article the other day neat bikes those 80's GP bikes so light and spindly and hand built.
One thing that's neat about the OW60 is the radiator is actually inside the frame allowing the front wheel to be closer to the frame.

Anyway what I do know is I could never do the stuff you do Neil, you are an artist with a mill.
https://www.pressreader.com/uk/class...82540133675797

https://www.pressreader.com/uk/class...83349/textview

[TZ350]

What a pity dumbarse Kawasaki gave up on the RV and just followed the others with reeds, never to do any good again with a twostroke, dickheads.

Yep, not much inovative engineering comes from design by accountancy.

[F5 Dave]

To be fair their reed KX and KDX of the time did pretty ok I thought.

[Flettner]

To be fair their reed KX and KDX of the time did pretty ok I thought.

yes but imagine if they were rotary valve, they could have been much better (in my opinion) and like Subaru, sales by point of difference. Silly old fools like me would go out of our way to purchase a RV engine bike, if not just because they are different. And now the age old problem of sharp power delivery is gone. And also now a 'relatively' clean (well better than a carburetor) exhaust with TPI.
I just can't wait to see how this 360 goes, if it's anything like my injected Bighorn engine it will be all worth the work.
But boy there is a lot of work in it yet.
made a stainless steel water pump drive shaft today and fitted the plastic gear to it, little battles.

[husaberg]

What was the last serious performance road bike made that had disc valves RG500? or KR250? both were made up until 1987 any others?
No Rob I am not including the GP125 Suzuki.

[TZ350]

I just can't wait to see how this 360 goes,

Me 2 ......... very exciting ..

[katinas]

Thanks Husa for KR/OW story and nice Video.
Just remember my meditation in second hand motorcycle shop, when left hand was on KR 250 ( red/black color with all exhaust adjustments ) other hand on NS 250. I really like KR engine, but NS chassis and 17 inch rear wheel overweight (three others two strokers in this shop, was RZ 250 and two RG 250).
Later, when guy who bought KR asked me adjust carburetors, I was very surprised, when noticed additional reeds.
He was not a two stroke man and I hear the story, that after usual two stroke caprice he burned down this KR. Maybe its true, because I've never seen this KR anymore.

[SwePatrick]

I have been simulating for hours for my friends 98cc minarelliengine.

One thing that amases me is section 2 on this printout.
Everytime i add a 'square' piece in the header it gives me a boost in power.
And almost everytime it raises the whole curve(and previous projects have shown the same in real life dyno)

By adding this i can run harder tapering on section 1 and 3 to acheive the same 'medium' tapering as a long header that replaces 1.2.3 sections would have to meet cylinder and section 4.

Anybody noticed the same?

Rgds


Attachment 335919

I quote my self if anybody want to hear the progress.
First pull on dyno, very raw and just setup to start and be safe in 'break in'
29.2hp to the wheel at 14300rpm on 98 octane pump fuel.
It revs very freely was the first spontaneus reaction, they pulled it all the way to 17000rpm by mistake
I´m sorry to say that i isn´t there where they dyno it, we just have contact through the phone as is.

Very low barometerpressure today in Sundsvall, only 1002hPa

[teriks]

@ Dutchpower,

Be careful, this photo of the transfer ducts represents the sand cores, with positioning apendices for the central core.
In addition, these are the core for the Suzuki RG500 cylinder which is much narrower than the FPE cylinder.

@ Frits,

I applied myself to compact the engine as much as possible, and also to privilege the mechanical accessibility and the flow of air behind the radiator.
During the study, I considered several configurations, tandem, V ...
Finally I chose a V/tanden.
As I reduced the distance between the two crankshafts, I did not have enough room for the base of the two cylinders side by side, so I opened very slightly cylinders , one with respect to the other (5 °)
And I prefer the dynamic balancing of the tandem, to that of the V one.

Attachment 335947 Attachment 335948 Attachment 335949

Beautiful! I can for sure appreciate the amount of hours behind such a model.
Even more so after spending _way_ too much time modelling a propeller and mold lately.

[TZ350]

I quote my self if anybody want to hear the progress.

Very interesting, I would love to hear more as the project progresses.