ESE's works engine tuner

[trevor amos]

Jan Thiel posting on the Bucket site, it`s true then, Christmas does come twice a year! Terrific to have you here Jan, welcome.

Trevor

[Frits Overmars]

. .

[Martin1981]

Wob I found this
You had a bit to do with some of his stuff earlier on.

http://nsr250.freeforums.org/tuckerb...s-t414-20.html

Hi Husa, i asked Tuckerbag the Questions about the Cylinder. In the drawing there IS a mistake, yes. So as i understand it Tuckerbag does NOT have a staggered cylinder. But wobbly HAS a staggered one. so i am excited and looking forward to what wobbly will find out about it. maybe one of only few existing staggered cylinder made by honda for what reason?


I am also very happy about Jan posting here now!

[Sketchy_Racer]

Well the last few months for me have been a great learning exercise. I've made pretty big changes to my NSR300 motor and found some good things along the way.

The first change I started experimenting with was the chambers. I went about modeling a FOS pipe in engmod and then tweaked dimensions from there. The biggest change that the engine so desperately needed was a increase in the nozzle diameter. As it would turn out all the trouble that I've had with detonation and having to run very very large jets to compensate was mainly due to this. As soon as the stinger was increased detonation in the simulation went away. So I've now gone from a 21mm nozzle to a 24.5mm nozzle. Massive change.

Next was the chamber itself. They Tyga chamber isn't too far off what I needed so with a cut of 40mm off the header and added 40mm into the belly it was in the ball park. This is still not the optimum and engmod suggests that there is still 4-5hp hiding in the chambers themselves, this is a work in progress.

Finally came the changes to the exhaust port. The NSR150 barrels come with parrallel exhaust duct walls. Again as suggest by engmod and researching on this fantastic thread I found there was to be much gained from porting into the side wall to get a larger flow area on the Ex port. As it seems to be the NSR150 barrels have enough transfer time/area but lack blowdown.





Finally when building the new motor I decided to also try using a radius on the edge of the piston, mainly for lubrication properties but also in hope that I may gain some flow when the ports are partially open.



The end result is this:



The change in engine characteristic is significant and on track the additional spread of power has transformed how I can ride the bike.

There is still a small dip in the power curve that I haven't had a chance to iron out yet. I believe this is just incorrect power valve timing

The only problem that I have now is that the motor revs too high and I'm worried about crank life. Does anyone have any good ideas on how to bring the power down the rpm range?

[jamathi]

Well the last few months for me have been a great learning exercise. I've made pretty big changes to my NSR300 motor and found some good things along the way.

The first change I started experimenting with was the chambers. I went about modeling a FOS pipe in engmod and then tweaked dimensions from there. The biggest change that the engine so desperately needed was a increase in the nozzle diameter. As it would turn out all the trouble that I've had with detonation and having to run very very large jets to compensate was mainly due to this. As soon as the stinger was increased detonation in the simulation went away. So I've now gone from a 21mm nozzle to a 24.5mm nozzle. Massive change.

Next was the chamber itself. They Tyga chamber isn't too far off what I needed so with a cut of 40mm off the header and added 40mm into the belly it was in the ball park. This is still not the optimum and engmod suggests that there is still 4-5hp hiding in the chambers themselves, this is a work in progress.

Finally came the changes to the exhaust port. The NSR150 barrels come with parrallel exhaust duct walls. Again as suggest by engmod and researching on this fantastic thread I found there was to be much gained from porting into the side wall to get a larger flow area on the Ex port. As it seems to be the NSR150 barrels have enough transfer time/area but lack blowdown.





Finally when building the new motor I decided to also try using a radius on the edge of the piston, mainly for lubrication properties but also in hope that I may gain some flow when the ports are partially open.



The end result is this:



The change in engine characteristic is significant and on track the additional spread of power has transformed how I can ride the bike.

There is still a small dip in the power curve that I haven't had a chance to iron out yet. I believe this is just incorrect power valve timing

The only problem that I have now is that the motor revs too high and I'm worried about crank life. Does anyone have any good ideas on how to bring the power down the rpm range?

Just make your pipe a little bit longer in small steps, maybe 5mm is enough. At the flange, or the beginning of the header.
21mm was surely too small!
You can use distance pieces between flange and header for quick tests.
I did this on my 50cc from 1969 with very good results

[Sketchy_Racer]

Just make your pipe a little bit longer in small steps, maybe 5mm is enough. At the flange, or the beginning of the header.
21mm was surely too small!
You can use distance pieces between flange and header for quick tests.
I did this on my 50cc from 1969 with very good results

Thank you Jan, I will experiment with this next time I am on the dyno.

[jonny quest]

Pipe length is easiest to try like Jan said.

The radius on the Pistons probably did the most damage to your powerband. That may have not been the best direction

[ief]

You're looking at the wrong one Jonny, he only wants to get rid of the flatter area before peak power.

[wobbly]

Yes, 21mm is WAY too small even for the 250 engine..
And looking at the PV,it wont be working hardly at all with that big space down each side.
You need to add weld to the PV blade side walls and grind pockets further up in the duct to get alot better sealing.
Also looking at the dyno curve the overev thru the gears would be all done at 12500 - that isnt reving hard at all.
From memory the Tyga pipes have way steep rear cones, that wont be helping the dramatic drop off in power past peak.
So I would be getting the header and diffuser length % correct,then lengthen the rear cone to gain some upper mid,without loosing
any overev.
The rear cone is easy enough to replace as a single section.
The other big issue with the 150 cylinders is that they have no port stagger,and the roof angles are very flat.
Fix that and you will pump up power everywhere.

[ken seeber]

. .

Jan, welcome. This makes it a Triple Whammy for ESE. The key thing is to keep these guys stimulated.

[TZ350]

So my friend Franco listened to me, I am happy to hear that!
I told him that in my opinion you are the best tuner in the world. Pesaro is a very nice place to be, I worked there for 1 year.
Hope you'll enjoy it!! And you will love the food.

Great to have Jan here and to hear his endorsement of Wobbly.

[JdG]

Jan Thiel calling you the best tuner in the world... That should shut up those who criticize Wobbly for a while...

[wobbly]

"That should shut up those who criticize Wobbly for a while"

Na wont happen, as I said at the time those smartarse flamers didnt criticize with any intelligent logic to justify their opinions,
they think personal attacks are clever and much more insightful, yea right.

I will just carry on helping out by detailing here what I think is the reality's of tuning 2Ts, and no matter what they may think or say - who got the
job at one of the best companies in the world actually building Championship winning engines.

Thanks Jan , I appreciate the kind words and all your help with my personal " education ".

[WilDun]

"That should shut up those who criticize Wobbly for a while"
Na wont happen, as I said at the time those smartarse flamers didnt criticize with any intelligent logic to justify their opinions.

Just let it all ride over your head Wobbly, everyone is entitled to their opinion, but history will eventually sort out whether they are right or wrong, meantime your "Wobbly Wisdom" is greatly appreciated and used by many here, (if not most), but you have a task ahead of you and you need to keep focused on that.
I don't have a lot of input on this thread, but from what I have seen, you are a great contributor.
Congratulations and good luck with the new job.

[sispeed]

Hello. I know there are at least to Posts stating that a motor with a leak in the case, Gasket or Seal, is running rich.
Unfortunately I can confirm that this is true. Had the Problem on my last race event on the German Sachsenring.
And like stated from Wobbly it sized as I went leaner on the main to correct. The surviving side was dark black. So all statements are proved an it was a sad day for me.
Since then I tried to get my head around why the the motor runs rich and what exactly forces the rich condition.
Can someone give an explanation on the effect? That would be great.
Thank you
Regards Siggi