ESE's works engine tuner

[husaberg]

There is totally nothing that looks like RSW/RSA on KTM 125 sx

The little uns 50 and 65.

[diesel pig]

Piecing together what i have found it seems pretty much anything two stroke right from the elisnore that came out of honda up until the late 90's had one designers fingerprints on it.

Do you mean Shin'ichi Miyakoshi? In Kevin Cameron's book "Classic Motorcycle Race Engines" he writes when Honda realised in 1981 they were never going to win with the four stroke NR500 (wags said the NR stood for never ready!) in GP500 racing and would need a two stroke. They needed someone with two stroke racing experience, Miyakoshi was the only one in the company who had it having headed the design of the MX Elisnore's in the 70's.

[husaberg]

Do you mean Shin'ichi Miyakoshi? In Kevin Cameron's book "Classic Motorcycle Race Engines" he writes when Honda realised in 1981 they were never going to win with the four stroke NR500 (wags said the NR stood for never ready!) in GP500 racing and would need a two stroke. They needed someone with two stroke racing experience, Miyakoshi was the only one in the company who had it having headed the design of the MX Elisnore's in the 70's.

Yip that's right according to legend he had brought a few overseas mx bikes and looked at them to see how they were built.
He then made the CR Elsinore and was testing it on the sly, supposedly without Hondas full knowledge and consent.
Soichiro honda was not impressed when he found out, but when it was shown to be rather good and a large potential seller he relented and let it proceed.
Miyakoshi's finger prints were on pretty much all Honda two strokes up to and including the NSR500 big bang as well as a lot of Four stroke in the 60's GP era
Another story is the original goldwing was designed and built only to be a flat six and when Soichiro seen it he made them turn it into a four.

[jato]

For a company that has always "believed" in 4 strokes i've always thought Honda make better two strokes than most of their competition - with the exception of the mvx 250...

[jamathi]

For a company that has always "believed" in 4 strokes i've always thought Honda make better two strokes than most of their competition - with the exception of the mvx 250...

Yes, they definitely did much better than Yamaha and Suzuki!

[Dutch Fisher]

Yes, they definitely did much better than Yamaha and Suzuki!

With the breath and depth of resources that Honda have, no surprises they'd be on top even if they did make the odd blunder in design or appilcation. So many resources infact, I'm in no doubt they designed the 250 twin crank in 1998 just for Katoh to take advantage of his small size. A japanese WC on a japanese bike, that s a big prize in the land of nippon.




Jan I'm curious, did any of the Japanese manufacturers ever approach you to work or do consultation on engine projects for them?

[jamathi]

With the breath and depth of resources that Honda have, no surprises they'd be on top even if they did make the odd blunder in design or appilcation. So many resources infact, I'm in no doubt they designed the 250 twin crank in 1998 just for Katoh to take advantage of his small size. A japanese WC on a japanese bike, that s a big prize in the land of nippon.

Honda also bought a 250cc ROTAX engine.




Jan I'm curious, did any of the Japanese manufacturers ever approach you to work or do consultation on engine projects for them?

I once talked with Yamaha-people.
Later I had an appointment with Suzuki-people, but then the 4strokes came.....

[Flettner]

ok, it would seem the Link ecu can 'read and hold' a crank case pressure value. Just not internally, but the ecu can drive some circuitry to read then hold an output from the MAP sensor. Using some transistors and a small capacitor, dumped and reloaded every cycle but only dumped when the main reading occurs then switched in untill the next cycle (reading).

[TZ350]

ok, it would seem the Link ecu can 'read and hold' a crank case pressure value. Just not internally, but the ecu can drive some circuitry to read then hold an output from the MAP sensor. Using some transistors and a small capacitor, dumped and reloaded every cycle but only dumped when the main reading occurs then switched in until the next cycle (reading).

I received my Speeduino fuel injection ECU kit today. Being a shield for an Arduino with open source code I should be able to write a sample and hold routine and incorporate it in the main control program. If not then I will follow Flettners lead and go the Link way.

[katinas]

[QUOTE=Dutch Fisher;1131105717]Well I never...

Another from "Well I never knew that...!" box.
When Kawasaki decide to return to 250, they started with pararel twin ( KR-1 street version) 1987-88 and ended in 1993 with radical upside down V 90 with firing angle 90 . But between this two versions was third (add photo): Well I never... "normal" engine position, V 75 angle with 105 firing angle in 1989-1990. Best result 17 place in All Japan Championship race in 1990.

After first period with V90 and 90 angle firing (inline crank pins), Honda release NSR with V75 in 1992 and RS/NX5 in 1993. With offset crank pins, firing angle 60 (if pins offset 15 degrees, not sure precisely, in advance position from the first working pin) and they hold this on RS until the end. But on NSR, from 1997 or 1996 ( except Katoh's two crank, real big- bang with 0 angle firing) and later RSW, they stick to Kawasaki's 105 firing angle, with 20 ( oh sorry 30 thanks Dutch Fisher) degrees crank pins offset in retard position from the first working pin.

But late Honda RSW 250 crank photo from 'Racers', with inline crank pins, probably indicate that they tried 75 firing angle on Aoyama's bike, maybe upgrade throught the 2009 season. But designed drawings on Aoyama's bike fairing from ignition side, show 105 pic up angle, but this is only paint.....

[JanBros]

[QUOTE=katinas;1131106071]

Well I never...

Another from "Well I never knew that...!" box.

But between this two versions was third: Well I never... "normal" engine position, V 75 angle with 105 firing angle in 1989-1990. Best result 17 place in All Japan Championship race in 1990

you are right about that !

any more info ?
I'm curious though : as it probably is one of the most secret race-bikes ever - only 2 outings known : '91 Shah Alam and '92 Daytona - : if it was raced in Japan how come in 1990, surely their should be some mention of it somewhere ?

[katinas]

[QUOTE=JanBros;1131106086]

you are right about that !

any more info ?
I'm curious though : as it probably is one of the most secret race-bikes ever - only 2 outings known : '91 Shah Alam and '92 Daytona - : if it was raced in Japan how come in 1990, surely their should be some mention of it somewhere ?

Yes, but this was upside down version V90 and very sad that they not return to V75 normal configuration ( say, with different, 54x54 mm) engine with new chassis after 1993. As I read, the chassis on late 93' with upside down engine was superb. V75- 50.6mm stroke, V90 upside down- 50.7mm.

Someone, even made 1/12 scale model of this 1989 bike with V75 engine, but foto only with the fairing.

[Dutch Fisher]

[QUOTE=katinas;1131106071]

Well I never...

Another from "Well I never knew that...!" box.
When Kawasaki decide to return to 250, they started with pararel twin ( KR-1 street version) 1987-88 and ended in 1993 with radical upside down V 90 with firing angle 90 . But between this two versions was third (add photo): Well I never... "normal" engine position, V 75 angle with 105 firing angle in 1989-1990. Best result 17 place in All Japan Championship race in 1990.

After first period with V90 and 90 angle firing (inline crank pins), Honda release NSR with V75 in 1992 and RS/NX5 in 1993. With offset crank pins, firing angle 60 (if pins offset 15 degrees in advance position from first working pin, not sure precisely) and they hold this on RS until the end. But on NSR, from 1997 or 1996 ( except Kato's two crank, real big- bang with 0 angle firing) and later RSW, they stick to Kawasaki's 105 firing angle, with 20 degrees crank pins offset in retard position from first working pin.

But late Honda RSW 250 crank photo from 'Racers', with inline crank pins, probably indicate that they tried 75 firing angle on Aoyama's bike, maybe upgrade throught the 2009 season.

As far as I can tell, all the V75 Honda are pin offset 30* firing angle 105*, its the natural setup for primary. That inline pin crank pic is a head scratcher, if anyone has the NSR250 Racers mag and can photo the pages at 3200 x 1800 (that sample page is at that reso and OCR'd perfectly) I'll happily translate the whole mag, just make sure that the pages are as flat as poss (sheet of glass with no reflections) we see what they say about Aoyama engine.

Katoh's appears to be a 120* twingle, again another natural angle for that design along with 90*, 60* and 180*


As for the Kawa 250 effort, a bit bizarre esp. keeping with the gen1 KIPS.

[katinas]

[QUOTE=Dutch Fisher;1131106092][QUOTE=katinas;1131106071]


pin offset 30* firing angle 105* .... Katoh's appears to be a 120* twingle, again another natural angle for that design along with 90*, 60* and 180*





Yes, I lost 10 degrees .....of course 30...thanks, but two cranks NSR drawing and technical info, indicate 110 cylinders angle and 0 firing difference

[Dutch Fisher]

[QUOTE=katinas;1131106093][QUOTE=Dutch Fisher;1131106092]

pin offset 30* firing angle 105*


Yes, I lost 10 degrees .....of course 30...thanks, but two cranks NSR drawing and technical info, indicate 110 cylinders angle and 0 firing difference

Another 'well i never' to the naked eyeball it appears 120* more balancing shenanigans from Honda