ESE's works engine tuner

[jonny quest]

I've heard of a lot of Honda cylinders being copied by other manufacturers. Why wasn't the RSA copied if it far superior?

Jan or Frits, have either of you helped any motocross teams with their engine development?

[peewee]

Why wasn't the RSA copied if it far superior?

because nobody could get their hands on one ? thats my guess anyways

[jamathi]

because nobody could get their hands on one ? thats my guess anyways

A Danish kart engine manufacturer bought an RSA cylinder at Aprilia and copied it.
A French kart engine manufacturer bought a complete RSA after the last 125cc race.
All 250cc superkart engines are now Aprilia copies.

[jamathi]

[QUOTE=jonny quest;1131105619]I've heard of a lot of Honda cylinders being copied by other manufacturers. Why wasn't the RSA copied if it far superior?

Jan or Frits, have either of you helped any motocross teams with their engine development?[/QUOTE

No, I never did!

[husaberg]

A Danish kart engine manufacturer bought an RSA cylinder at Aprilia and copied it.
A French kart engine manufacturer bought a complete RSA after the last 125cc race.
All 259cc superkart engines are now Aprilia copies.

The KTM MX cylinders show a definite Aprilia influence.
As do the DEA cylinder moulds i have, they well buggered up your septum's though.
The rest is pretty close to the RSV/RSW era cylinders though.

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.

[katinas]

Remember very serious efforts from Holland with Honda RS 125 engines and Aprilia type cylinders, with very good results, but can't find quickly. They adopted biggest Honda CR 125 four petals reed cage version for this project

[husaberg]

We are saying the same thing..


At the risk of the blind leading the blind (kinematics are my weakest topic) here's a theory.


Using the formula I stated earlier (2xAv)-180) the 112* comes out spot on at 44* pin offset.
That means primary balance is achieved right there, as noted by the zero piston accleration on the bottom cylinder and max decel on the top cylinder (TDC)

The fly in your soup is the secondary forces are having a party in a wasps nest and buzzing away merrily.
I've modded the pic and added the sum of inertia force lines of the secondary in yellow.
Now it seems Honda has approached this problem (likely 2 mins on the back of a cigarette packet for them) by reduced the crank balance factor to 50% and added that other 50% to the balancer so maintaining primary balance. This has allowed them to use a good % of the rotating interia of the balancer counter weight (thats counter-rotating) to offset a fair degree of that untamed secondary inertia force.
The counter force angles are not absolutely in-line while at their respective peaks, but it looks like the level of vibratory forces is reduced to the point that its ok to solidly mount the crankcase into the frame.

I found this bear in mind its been translated from Japanese to english

Supplement 2 Description of Riding Sports 2012-9
　"Although this engine is a two-cylinder simultaneous explosion engine, since the two banks explode simultaneously at 68 ° -292 ° intervals ~ V bank angle of NSR 500 is 112 °, theoretically the primary vibration is zero For this reason, the balancer shaft became unnecessary in the 1992 model, and due to the three-axis configuration, the rigidity and precision of the engine alone were upgraded "(page 58)
As with supplementation 1- (2), it seems that Mr. Writer misunderstood that the 1992 type NSR 500 misunderstood that the primary inertial force is perfectly balanced without the balancer shaft. "Three-axis configuration" ... ... "Exploring the NSR 500 Hyper 2 st engine" (Tsukasa Tsukasa, 1995 Grand Prix publication) Other publications have written about the balancer shaft (that is, it becomes a 4-axis configuration) It seems to be a product of imagination due to wrong recognition of Mr. Lighter's primary vibration.

Remember very serious efforts from Holland with Honda RS 125 engines and Aprilia type cylinders, with very good results, but can't find quickly. They adopted biggest Honda CR 125 two petals reed cage version for this project

Frits knew the guy they dont do them anymore very nice looking cylinders..
there are some pics in my aprilia and my crankcase album.
I think it was the same guy that was doing the doubled up disc valve crankcases.

Last time i looked at his site it had mainly 4T stuff plus the odd 2 stroke mini bits and bobs.
It was three initials JHE? or somthing its one my other computer.

[katinas]

This project

[jamathi]

I found this bear in mind its been translated from Japanese to english



Frits knew the guy they dont do them anymore very nice looking cylinders..
there are some pics in my aprilia and my crankcase albulm.
I think it was the same guy that was doing the doubled up disc valve crankcases.

Last time i looked at his site it had mainly 4T stuff plus the odd 2 stroke mini bits and bobs.
It was three initials JHE? or somthing its one my other computer.

I think you mean my friend Thijs Hessels.

All RSA cylinders were tested on a RSW engine.
Because to work well on an RSA you had to cut off the under/rearside of the cylinder....
As it stood in the way of the RSA's inlet flow.
After that it gave less power on the RSW and 250.
And most cylinders were destined for 250...

[husaberg]

I think you mean my friend Thijs Hessels.

All RSA cylinders were tested on a RSW engine.
Because to work well on an RSA you had to cut off the under/rearside of the cylinder....
As it stood in the way of the RSA's inlet flow.
After that it gave less power on the RSW and 250.
And most cylinders were destined for 250...

Thats him
Was it him who was making the CNC double disc crankcases?

[jamathi]

Thats him
Was it him who was making the CNC double disc crankcases?

Yes, but not 1 engine was ever finished....

[husaberg]

Yes, but not 1 engine was ever finished....

So what happened to all the cases?

[Dutch Fisher]

Well I never...


What I first thought was water cooling for the Aoyama RSW crankcase, turns out to be air cooling.
Having seen an air scoop under the engine in pics of the bike sans bodywork, I turned the old brainbox over with my fav cranking handle and concluded that it was an entry for a gearbox oil cooling system. Wrongamondo!!

I guess you could call it air cooling, more like an active insulator for the CC from the heat of the GB

Honda state on their website that the 2009 bike was 'old', I'm not so sure, i can't as yet find this air cooling system (the big black air scoop) on the 2006 bike. Has anyone?

[dutchpower]

[QUOTE=husaberg;1131105671]The KTM MX cylinders show a definite Aprilia influence.


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

[katinas]

Looks nice and compact

https://grassrootsmotorsports.com/ar...trokes-genius/