ESE's works engine tuner

[skako]

Your book is in better shape than mine, Skako. You wouldn't happen to have two copies of Band 1, would you?

I'm sorry I don't have band 1.
Band 2 is the only one I have from Jante.

[Jan Van Hamme]

Thank you very much Jan. I've got Band 2 here but am still looking for Band 1. I will contact them and see what they've got.

Maybe Band 1 from this other website ? I don't know how Band 1 looks like.

[skako]

I'm sorry I don't have band 1.
Band 2 is the only one I have from Jante.

Excellent, Skako. So you have Jante's books too? For those who are curious now: "Über Verbrennungsmotoren und Kraftfahrwesen, Band 2" by professor Alfred Jante.
It won't be easy to find those books now, but if you manage to do so, please let me know; there is still a volume missing in my library.

The research on of the exhaust top edge radius, page 333 and subsequent, shows that Jantes NZD 12.5 research engine had a bore of 90 mm and a stroke of 125 mm.
My research into the effects of the bore/stroke ratio led me to make the radius dependent not on the bore, but on the stroke, and I found an optimum at 5% of the stroke.
Attachment 354006

On page 319, the exhaust duct has a large radius drop that is approximately 78% of the cylinder diameter, at an angle of about 35° to the horizontal plane. The large radius on the upper edge of the port transitions into a smaller radius that is about 11% of the cylinder diameter.
These ratios are according to my approximate estimation based on the data and drawings that can be seen in book Band 2.
Sorry, I did something wrong with these double repeats.

[Frits Overmars]

Maybe Band 1 from this other website ? I don't know how Band 1 looks like.

Thank you once more Jan. I am going to try that.

[Pursang]

If both the piston and the exhaust port have a timing radius, and if both radiuses are not tangential to the bore, and if the top of the exhaust port has an elliptical shape, then calculating the open port passage degree by degree for the purpose of determining the angle.area becomes quite a job. Thank god for computers.
Attachment 354007

Reminiscent of the significant improvement in flow that can be achieved by using multiple angle cuts on poppet valves and seats.

[F5 Dave]

If both the piston and the exhaust port have a timing radius, and if both radiuses are not tangential to the bore, and if the top of the exhaust port has an elliptical shape, then calculating the open port passage degree by degree for the purpose of determining the angle.area becomes quite a job. Thank god for computers.

Oh he absolutely hates them. They have helped disprove his existence multiple times and you don't even want to know the logical logistics for him to even form that opinion.

[Frits Overmars]

Reminiscent of the significant improvement in flow that can be achieved by using multiple angle cuts on poppet valves and seats.

Watching that image makes me want to cry. What happened to common sense? I can't imagine anyone would want to improve flow by cutting multiple angles on poppet valves and seats. I would leave out the poppet valves completely. I would also leave out the four-strokes completely. But if you insist on four-strokes, imagine the significant improvement in flow that can be achieved by substituting those multiple angle cuts with radiuses.
I happen to know some otherwise decent people who work on four-strokes, so I'm not completely unaware of what goes on there. Radiusing is common practice in competition four-strokes and has been so for a number of decades.

[wobbly]

Yes Frits , radiused geometry is now commonplace since Rottler introduced multiple axis CNC porting machines with spindle cutting heads that can also form any shape in the seat area.

[SwePatrick]

Just some info of my tzr250 i´m converting to fuelinjection.
It isn´t by far finished in dyno(mapping) but it seems very promising, a lot of wheelspin halters my progress, but i´ll change the tire for the coming weekend(reduce slip).

But i wanted to share with you the gains of having a seriously short intake compared to normal.
In my case the normal intake with carburetor was about 130mm long.
It is now only 35mm long.

And in picture below, in the white quadrant there wasn´t any power before, it just fell on it´s nose after ~11500rpm, at 12000rpm i had about 5-8hp left, now it is above 50hp.
And i haven´t really lost anything in midrange and on the left side of the curve, i can´t say exactly as it is slipping on the dyno.(maybe after this coming weekend i got more info on that)
I also marked with a red arrow some slight misifre i had, probably due to not 100% correct fuelmap yet, it was worse at first, but after some pulls when i richened it up in steps, it started to go away.
If probably is just adding some more fuel in that area it will go away, and maybe some more hp.
But my tire was melting so i had to end the dynoday.
IR gun said the tire was 82-85c hot, it was very 'wet' when i laid my hand on it, i actually got stained black *lol*
Best before ending it was 71.4hp, i have dynoed more with carburetors.
That was with a lot less wheelslip, so probably it is equal now, but i can´t say just yet.

I will when i feel i am very close, mount the wideband sensors and finetune it.

Best of all, rock solid idle and lowrpm drivability, really smooth.
And idles perfect from cold to hot, and coming down to idle perfect after some hard pulls on dyno.

Very pleased so far =)

[SwePatrick]

Watching that image makes me want to cry. What happened to common sense? I can't imagine anyone would want to improve flow by cutting multiple angles on poppet valves and seats. I would leave out the poppet valves completely. I would also leave out the four-strokes completely. But if you insist on four-strokes, imagine the significant improvement in flow that can be achieved by substituting those multiple angle cuts with radiuses.
I happen to know some otherwise decent people who work on four-strokes, so I'm not completely unaware of what goes on there. Radiusing is common practice in competition four-strokes and has been so for a number of decades.

I need to argue with you Frits.
You are not always correct.
Radius seats are commonly NOT used due to wet flow do not like it.
In exhaust you can use it.
I´ve been porting foulstroke heads on a very serious level for about 5-6yrs ago and further back in time.
I often reached the same levels of power as professionals did, this with my 'hobbylevel' of knowledge.
On turbocharged engines i often reached far more power, or to say it otherwise 'the same power' but at far less boostpressure.

The idea of not having radiused seat on intake is that you need those abrupt corners between the different faces to keep the fuel atomized and suspended in air column.
It has been verified many many times in motorsport.
We can take Pro stock in dragracing, 8liter V8 with poor technology is reaching more power per litre than many highly tuned engines with 4valve technology.
And the tuners all agree there, you need those non radiused seats.

Dry flow is an another thing though =)

[Pursang]

Yes Frits , radiused geometry is now commonplace since Rottler introduced multiple axis CNC porting machines with spindle cutting heads that can also form any shape in the seat area.

Multiple angle cuts were obviously not optimum but were a means to achieve some consistency in multiple cylinders with manual machining operations. It was more about the similarity of the image than the finer details.

As wobbly says, Four Strokes now have 5 axis CNC porting machines. The valve pocket and tract is not too hard to imagine as a transfer port or exhaust duct.


If 'precision' radiused port openings and piston edges are able to produce valuable improvements in flow volume and directional control a Computer controlled tool would allow quick and consistent experiments and/or performance upgrades to production units.

[aljaxon]

spent the last few days searching this thread and i like the idea of a two stage header with wobblys 2/3 1/3 dimensions but am struggling to fit in the 3.5/5.5 angles along with a 3 stage diffuser with a sharper angle last cone to give more front side power. if i try and incorporate all this and the 32/68%
my belly goes too large in diameter. over 3.5x my duct exit diameter. 25mm . i cant have the main diffuser more than 12 degrees. and even then my last diffuser isnt much steeper.
can i use a two stage header but with angles 60% of the recomended @ 2.1/ 3.3 ? that only saves me a fraction.
or can i ignore belly diameter and my diffuse sections would go 8-12-18 degrees and follow roughly the lengths of the various pipes ive seen on here. wobblys wr200 pipe layout seems similar to my needs except it doesnt have the steeper
last diffuser
my rear cone im guessing a bit less by 2 or 3 degrees. 22.

aiming for wide power emphasis on front side.

i can make 3 pipes with variations and see how they perform on the dyno.

[wobbly]

As with all of the results gained from the black art of pipe design everything is a compromise and no free lunches are available.
To gain front side I would go with a slightly steeper single stage header say 4* with a two stage diffuser , making the second cone quite long and steep.
But 18* is very steep in any mans pipe design manual ,so I think shooting at that number is too limiting , if a smallish center section is deemed desirable.
Why the emphasis on a pipe with a narrow belly , this is only mandatory in old engine designs with lift shaft transfer ducts and no inner radius to keep the transfer streams on track,
away from the Exhaust port.

EDIT - SwePatrick , just a couple of observations re your SportsDevices printout.
Why is there a ratio difference with the two files shown ?
The DIN700 correction is useless for a 2T - JIS D1001 is far better or the latest update V41 has the FOS correction option that works very well.
Your graph is showing either you do not have enough trigger teeth to give enough data points for better resolution , or you have very low smoothing in operation - no way does
an inertia wheel jerk from rpm to rpm point like that.
Here is a sample run off my SportDeviced rig - it has 124 teeth on a starter ring gear 1:1 with the wheel , and minimal smoothing.

[SwePatrick]

away from the Exhaust port.

EDIT - SwePatrick , just a couple of observations re your SportsDevices printout.
Why is there a ratio difference with the two files shown ?
The DIN700 correction is useless for a 2T - JIS D1001 is far better or the latest update V41 has the FOS correction option that works very well.
Your graph is showing either you do not have enough trigger teeth to give enough data points for better resolution , or you have very low smoothing in operation - no way does
an inertia wheel jerk from rpm to rpm point like that.
Here is a sample run off my SportDeviced rig - it has 124 teeth on a starter ring gear 1:1 with the wheel , and minimal smoothing.

Different days, different gears(front sprocket, and also slip), i thought that was obvious as the name of the runs kind of hinting on that =)
But upcoming weekend it will sadly enough differ again as i´m about to change rear rim and tire to a known good kombo that doesn´t melt on the roller
I do run quite low smoothing as i want to se small changes in fuel and ignition map, running more smoothing just lowers the numbers very little, up to only ~1hp.
And this isn´t any hunt for most hp in the world at this point, so i don´t need to be 100% correct, i only need to see changes.

I´m not a fan of FOS compensation as it is the one that adds the most power, but i also need to say i actually haven´t studied what to use, i only just chose the one that a friend of mine runs in he´s cardyno and settled with that.

I´m running if i remember 16 tooth on the triggerwheel at the roller, (the one that was included).
Earlier i had Performancetrends system and it never showed what you mention even though i just had one triggerpoint per revolution.
And about v4.1, it is actually quite buggy.
You can also spot there is no torque reported, i later on loaded the runs into v4.0 and it showed torque, so it was recorded, but not presented in v4.1.

But i also got a starterring, so i might test that in the future.

[SwePatrick]

A little video of me just not getting it(to start with)
I have my excuses, but i won´t drag them to the surface here