ESE's works engine tuner

[katinas]

[QUOTE=Dutch Fisher;1131106092]

That inline pin crank pic is a head scratcher, if any.

Yes, specification table indicate that from 2002 to 2009 on RSW just V75 and 105 firing used, only 40mm carb was used from 2006.
So Kawasaki starting, Honda ending (maybe with 75 firing, inline pin crank, like they started in 1984 with V90).

[guyhockley]

Not a 2 stroke question but... That looks like a Hurst Airheart master cylinder in the inset photo. Did the Enfiled run a rear disc, or was it a rear hydraulic drum brake, in '65?

Way, way off topic, sorry TZ, but I said I'd check this out... weeks ago.

Better late than never, hopefully. This is what I've got.

[katinas]

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

Jan, maybe you have some ideas about this Yamaha 250 rotary engine. Its V60 and from ignition side looks like firing on both cylinders at the same time.

[JanBros]

[QUOTE=katinas;1131106087]

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.

So basicly the 2 prototypes known to mortals (one with upsidedown forks, other one with right side up) are very different ? How come you know about the V75° if I may ask as you appear to be a non-mortal any more info ?

[katinas]

[QUOTE=JanBros;1131106102]

So basicly the 2 prototypes known to mortals (one with upsidedown forks, other one with right side up) are very different ? How come you know about the V75° if I may ask as you appear to be a non-mortal any more info ?

Mortal, have some experience. All info from Racers magazine, I am really surprised too when found this. From all photos on internet about Kawasaki X-09, it easy indicate who is who.
With upsidedown forks and with right side up with casting legs- V90 upsidedown engine.
With right side up forks and brown anodized legs made from billet or two piece - V75 engine.
Fairing on V75 with big side ducts for air from radiator.

[katinas]

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.

Yes, and Katoh, as wild card, wins first 1998 season Suzuka race with new, first generation, two crank engine. And very interesting, with new lead free fuel regulation, they started with under square 52x58mm configuration, mainly to minimize detonation with smaller piston. But later, return to 54x54mm, because no gains and some power lose.

[Dutch Fisher]

Looks like the big bang was designed to have zero piston acceleration on the bottom cylinder while the top cylinder was on max deceleration (TDC)

Hold on a minute there cowboy, seems my engineer eyeball has tripped me up again.
A few light fandangos with the fingers on the special calculator and using Hondas fav 104mm rod C-to-C and 27mm crank radius (54 stroke)
we've got max piston velocity (zero accel) at 76.6* not 68, opps! luckily the top cylinder is on max deaccel.

[crbbt]

Anyone happen to know the radius of the dome piston for a CR250 (05-07)

[husaberg]

Yes, and Katoh, as wild card, wins first 1998 season Suzuka race with new, first generation, two crank engine. And very interesting, with new lead free fuel regulation, they started with under square 52x58mm configuration, mainly to minimize detonation with smaller piston. But later, return to 54x54mm, because no gains and some power lose.

When you look at the Twin crank Honda layout its rather seems to be a tacit admission from Honda they cant match the Aprilia on HP
So they try the next best thing attempt to repackage the bike to make it narrower.
From Memory the Twin crank had the side mounted radiators as well. (Shades of NR500)
The radiators normally being the widest part of the frontal area.
On a side note The other possible reason for the twin crank which would cost HP would be to less the Gyro.
Honda had made up twin crank NSR500 prototypes in 1987 and i believe again in 1992.

Thanks, very interesting story.
I am very surprised when found this photo, that shows how Honda was keen about carbon comstar wheels, even after some Spencer's era problems. One of many changes that E. Lawson tried in 1989 was comstar "2nd version" front carbon wheel and AP brake discs. Carbon 3.75x16 =2.5kg, magnesium=2.6kg, but 17in version carbon= 2.83kg magnesium=2.81kg.

You showed a carbon wheel on Lawsons bike the other day.
I can confirm that not only were they used on the Freddie Spencer bikes a few years prior to that the wheels that Lawson used actually were left overs from Freddies bikes as Honda considered it to costly to make more.

one os Freddie's bike also had CF reinforced forks. as did Lawsons
Freddie had one wheel blow to bits at south Africa one year from the early batch.
He had used Carbon discs in 82 and even A CF swingarm at various times on The NS500.

Honda painted up the CF swingarm so it looked aluminium.

Pretty sure the NR500 had Carbon wheels and Discs at one stage as well, it certainly had a CF frame in one version. (cf swingarm as well)

A lot of people say Honda should have won GP bike classes as they used huge resources and money i dont really find that rings true when you look at the size of the crew Kenny Roberts had compared to HRC.

[katinas]

....On a side note The other possible reason for the twin crank which would cost HP would be to less the Gyro.....

With two crank configuration they equalize both cylinders inlet and exhaust, this help on power side.
Cost HP only on 52x58mm config. and with bad cooling from side radiators in 1998 (very young engineers team involved in this project with swingarm-crankcase attachment experiments ), but return to 54x54mm in 1999 on two crank engine with front side radiator and gain HP again. 2000-2001 they are very happy with the bike, but when Katoh won championship, goal was reached, all resource was redirected to last NSR 500 and 4-t.
So 250 team left to do something with RS/NX.

[husaberg]

Cost HP only on 52x58mm config. and with bad cooling from side radiators in 1998 (very young engineers team started this project), but return to 54x54mm in 1999 on two crank engine with front side radiator and gain HP again. 2000-2001 they are very happy with the bike, but when Katoh won championship, they reach the goal, and redirecting all resource to last NSR 500 and 4-t.
So 250 team left with RS/NX.

Yeah it might have had more HP, But thats only part of the equation of what makes HP, What i am saying is two cranks cost HP in friction compared to the same spec single crank.
Every thing else being equal ie cylinders, pipes, carb, intake layout, airbox etc. A single crank will give more HP just as a Disc valve will give more hp than a reed will., which is the path Yamaha choose to use to stay competitive with Aprilia.
Funny enough when they made the origional NSR they played with lots of bores and strokes, I was stunned to learn they would at the time have preferred the 56x50mm but didn't want to compromise width on the first design NSR500.
They (at the time) relied on the tech of materials to achieve the same revs with a longer stroke. time has proven a square engine is the best compromise (at this time anyway.)

What i was meaning is i think Honda designed the twin crank NSR250 to bias towards aerodynamics rather than HP. (twin crank and side radiators)
Another interesting snippet from Spencer was he raced and won in one GP on a two up crank configuration, at least three years before Honda decided to standardize the layout. (which is a shame)

[JanBros]

Anyone happen to know the radius of the dome piston for a CR250 (05-07)

3mm dome height

http://www.mitaka.co.uk/HONDA%20PISTONS/PT.05CR250.htm

[F5 Dave]

. . .
A lot of people say Honda should have won GP bike classes as they used huge resources and money i dont really find that rings true when you look at the size of the crew Kenny Roberts had compared to HRC.

At the track or at the factory?

[husaberg]

At the track or at the factory?

At the track Team Roberts would have outgunned HRC by 10:1 Even Kocinski said the same.
I cant remember what he said, but is was something like "look arround team roberts has 80 people HRC 10 and we are still getting smoked....
HRC was big of course about 400 people, but they also did a lot of other stuff, trails, MX and Superbike plus building the customer GP bikes etc.
Aprilia out of a total workforce of 450 i understand had about 62 people in the race program.
I have no idea what Yamaha had them but i know they have 67 engineers back in japan on the YZRm1 MotoGP team alone.
Plus 17 in italy and 55 at each GP.
https://www.cycleworld.com/2014/12/0...umbers#page-18

[TZ350]

Got my Speeduino fuel injection CPU kit. Put it together and started to find my way around it and understand its methodology.



Interesting system. It has staged injection but instead of it being the small or large injector the Speeduino fires both together but varies the on time of them individually to suit.