ESE's works engine tuner

[Frits Overmars]

This youtube video clip is from our onboard model engine flying in circles at about 275 km/h on control lines. Not fast really, but shows the head temp in deg C.
For the model engine when it stopped it got to about 218C or so, but during the run is in the 203C range. The glow plug was looking like new.

How about the glow plug temperature modulation Neil? Any news?

[Lightbulb]

Sorry Frits, just had too much trying to get this all working and fitted to a model. There is a circuit plan and another hall effect backplate made. Still have to make the new backplate data board that is adjustable to see where the timing of it needs to be etc. We have tested that on the bench we can augment the wire of the glow plug. On the bench it is difficult if it is actually doing anything, as it looks a continuous glow, bit like a filament lightbulb.
Neil

[wax]

This is the piston from my reed cylinder and some ideas from other people. i notice wobbly a while back you said to make the holes as low as possible n the skirt. Im trying to figure out why you said that and which configuration you would go with as a starting point if this was your cylinder you were setting up
thanks

[peewee]

i believe you want the piston windows low because the intake phase doesnt start until the piston is well on its way up from bdc. perhaps around TPC or even alittle later. at bdc if you put the piston windows in full view of the cylinder inlet, the windows will already be to far up the stroke by the time inlet starts. draw imaginary windows with a pencil and rotate the piston and you can see what happens. im not for sure but i think the faster the cyl pressure drops during the exh phase, the sooner the inlet phase can start.

[Frits Overmars]

We have tested that on the bench we can augment the wire of the glow plug. On the bench it is difficult if it is actually doing anything, as it looks a continuous glow, bit like a filament lightbulb.

It will be a continuous glow; the thermal mass of the plug filament is much too big to expect anything else. But I think you should be able to keep the glow somewhere between red-hot and yellow-hot.

[wobbly]

+1 what peewee said.
Most engines the reeds have only just started to lift,between BDC and TPC.
What opens the reeds initially is the case going below atmospheric and the intake wave going + at the same time.
Depending upon what harmonic is active in the inlet pipe and at what rpm, the + wave can be closer to BDC or closer to TPC.
The two actions together + the rising piston dropping the case pressure opens the reeds.
Thus the lower the piston cutouts the better, and the flow requirement of the intake to make the power needed will dictate how much piston cutaway
and skirt hole area is needed.
As power rises it is first better to be looking at floor ports and or Boyesens down the side into the case, before doing the piston, as any holes create the oportunity
for destruction.
Here is a 66mm Wossner as used in my RZ400, I made the ports a little smaller as the skirts were just starting to crack at 500Km of 12,000 rpm racing.
No issue since then.

[wax]

Thank you , once again you guys have been very helpful

[Muciek]

Hey Wobbly, did You finished the engine with that special casting of the ex port?(400cc racer)

[katinas]

This is the piston from my reed cylinder and some ideas from other people. i notice wobbly a while back you said to make the holes as low as possible n the skirt. Im trying to figure out why you said that and which configuration you would go with as a starting point if this was your cylinder you were setting up
thanks

Have experience only with big Boyesens Reed Cylinders (Honda NS 250/400). Original pistons have two holes very low, but when I put the piston without any holes, mid power goes up, acceleration much better without any dip and very linear throttle response (very nice to ride), did not notice difference on top. Even without ATAC feels stronger than original pistons with ATAC. And every time when made any holes in pistons, especially on upper skirt side (cylinder with Boyesens) always was worse bottom and mid. I think, that size of cutaway on piston intake side, depends on how big Boyesens are and the holes in piston weakens flow through A B at low and mid revs.

Honda from 1980 to 1986 playing with Boyesens on CR 125 reed cylinders and piston intake side cutaway. They try bigger and smaller Boyesens, and smaller arrangement looks more like help for C than for additional suction. On first RS 125/250 with reed cylinders, they used big Boyesens, but with CR125 ended with small ones for better bottom and mid.

With Reed Cylinders without Boyesens (or with very small), there is no other way for additional mix and better flow in C, just through piston, so for more power, holes are necessary, but I do not have experience with that type of cylinders.

If your cylinder is with big Boyesens and you need mid power, would be interesting to try piston without any holes, and later try cutaways or holes in small steps and write.

Interesting, how C port influence engine power at low and mid revs. Maybe closing/opening valve on C duct, will work in simillar way like powervalve?

[TZ350]

Started to make progress with a piezo amp and getting a clean usable signal. The ignition trigger pulse is on the bottom line as a marker. The just before exhaust port opening pressure peak (top line) was in the right place and of the right amplitude to be useful as an input for the Arduino. Worked well for a while then turned to mush.

I suspect the piezo crystals are getting hot and giving up. Know more tomorrow night when I try again after they have cooled down.



Jaycar op amp kit KC5531 setup as a single channel and for piezo input.

[husaberg]

Started to make progress with a piezo amp and getting a clean usable signal. The ignition trigger pulse is on the bottom line as a marker. The just before exhaust port opening pressure peak (top line) was in the right place and of the right amplitude to be useful as an input for the Arduino. Worked well for a while then turned to mush.
I suspect the piezo crystals are getting hot and giving up. Know more tomorrow night when I try again after they have cooled down.
Jaycar op amp kit KC5531 setup as a single channel and for piezo input.

Rob did you know they have water cooled Piezo's they are more stabe in regards to drift.

[Norman]

Have experience only with big Boyesens Reed Cylinders (Honda NS 250/400). Original pistons have two holes very low, but when I put the piston without any holes, mid power goes up, acceleration much better without any dip and very linear throttle response (very nice to ride), did not notice difference on top. Even without ATAC feels stronger than original pistons with ATAC. And every time when made any holes in pistons, especially on upper skirt side (cylinder with Boyesens) always was worse bottom and mid. I think, that size of cutaway on piston intake side, depends on how big Boyesens are and the holes in piston weakens flow through A B at low and mid revs.

Honda from 1980 to 1986 playing with Boyesens on CR 125 reed cylinders and piston intake side cutaway. They try bigger and smaller Boyesens, and smaller arrangement looks more like help for C than for additional suction. On first RS 125/250 with reed cylinders, they used big Boyesens, but with CR125 ended with small ones for better bottom and mid.

With Reed Cylinders without Boyesens (or with very small), there is no other way for additional mix and better flow in C, just through piston, so for more power, holes are necessary, but I do not have experience with that type of cylinders.

If your cylinder is with big Boyesens and you need mid power, would be interesting to try piston without any holes, and later try cutaways or holes in small steps and write.

Interesting, how C port influence engine power at low and mid revs. Maybe closing/opening valve on C duct, will work in simillar way like powervalve?

Katinas, I find your posts about new flow paths and so on very interesting. Hopefully you will be able to do some real testing as the snow goes away..? About the "c-port powervalve", your thought is that the c-port shall be blocket up until about mid-range?

[wobbly]

Musiek, yes that has been done for a while.
The owner is very busy with a new bike shop business,but has been making cold air intakes and Titanium axles etc.
It will be on the dyno soon.

[wax]

Have experience only with big Boyesens Reed Cylinders (Honda NS 250/400). Original pistons have two holes very low, but when I put the piston without any holes, mid power goes up, acceleration much better without any dip and very linear throttle response (very nice to ride), did not notice difference on top. Even without ATAC feels stronger than original pistons with ATAC. And every time when made any holes in pistons, especially on upper skirt side (cylinder with Boyesens) always was worse bottom and mid. I think, that size of cutaway on piston intake side, depends on how big Boyesens are and the holes in piston weakens flow through A B at low and mid revs.

Honda from 1980 to 1986 playing with Boyesens on CR 125 reed cylinders and piston intake side cutaway. They try bigger and smaller Boyesens, and smaller arrangement looks more like help for C than for additional suction. On first RS 125/250 with reed cylinders, they used big Boyesens, but with CR125 ended with small ones for better bottom and mid.

With Reed Cylinders without Boyesens (or with very small), there is no other way for additional mix and better flow in C, just through piston, so for more power, holes are necessary, but I do not have experience with that type of cylinders.

If your cylinder is with big Boyesens and you need mid power, would be interesting to try piston without any holes, and later try cutaways or holes in small steps and write.

Interesting, how C port influence engine power at low and mid revs. Maybe closing/opening valve on C duct, will work in simillar way like powervalve?

Thanks for that, the boysens are not to bad on this cylinder. Interesting you found a gain with no piston holes

[chrisc]

I brought a carving blade to a gun fight back in December at the Southern Classic! Riding against 250cc 4t, 150cc 2t and 150cc 4t production bikes, I wheeled out my 1991 Honda RS50 for some fun in the twisty bits. With only 15hp, she goes alright... enough to put me 7th on a grid of 36 bikes in qualifying! This was the first race and unfortunately my GoPro failed in the next race so didn't get any video where I actually hustled a few 250s. The 3rd race I overheated the poor little thing and seized it at 143km/hr all the way to the hospital with a bruised lung hahaha. I did set the 5th fastest time overall up to when I crashed though. A 1:20.751 was my best time.

It's clear I stuffed up and overrevved the poor girl a few times at the start of the race. It was my first time riding the bike there so was still figuring out how to get it around the circuit. I'm eager to try again when she's going. I think a sub 1:20 is possible which would be faster than most the 250s.