ESE's works engine tuner

[Muhr]

Welcome Johan. Your drawings are looking real nice. Why did you decide to build a 100 cc engine? Is there any form of competition you can use it in?
You may have seen the JBB-pictures I posted earlier, but in case you missed them, here they are once again.
If you wish to Google: JBB stands for Jean-Bertrand Bruneau, a French dentist with many original ideas about motorcycle chassis and engines.
Attachment 333710 Attachment 333711 Attachment 333712

I have experienced that small rotary fed engines are very sensitive to the intake area crankcase volume and pipe area. Have you experienced any difference in a v-twin? Are they more forgiving in terms of time area?

[guyhockley]

Chris, sorry to hear you have had a bit of a nasty off, get well soon. best wishes from Team ESE for a speedy recovery.

Same from me.

[Frits Overmars]

I have experienced that small rotary fed engines are very sensitive to the intake area crankcase volume and pipe area. Have you experienced any difference in a v-twin? Are they more forgiving in terms of time area?

When it comes to gas dynamics and thermodynamics, I tend to treat any twin as two singles; in my experience all gas exchange processes in a twin are identical to those in a single. Engines with 1-in-2 inlet systems (Trabant) and 2-in-1 exhaust systems (BRP-Rotax) excluded of course.


By the way: that Rotax engine could be shoehorned into a Trabant without much effort. Imagine standing at the traffic lights with your little two-stroke car merrily bubbling away, nobody having a clue that instead of 26 HP you now have 165 HP under your right foot .

[Frits Overmars]

Following on from Nath88’s suggestions about the amount of air flowing through the motor that needs fuelling depends on whether the motor has fired and the pipe action has sucked air through or not.

Excellent lecture from Clint Gray, combining theoretical knowledge and practical thinking. I especially like the simple asymmetrical signal spacing.
Here is some more injection lecture for the Christmas holidays:

EDIT: uploading failed because the file is too big (2793 kB). You might try to find it yourself on the internet.
Search for WO2016193902A2 : Internal combustion engine having two fuel injectors per cylinder and control method therefor.

[SwePatrick]

'It' has been done....

http://teknikensvarld.se/provkorning...rt-800-173151/
https://www.youtube.com/watch?v=uxTG1tCMAtc

Still not fast thou

[ken seeber]

Excellent lecture from Clint Gray, combining theoretical knowledge and practical thinking. I especially like the simple asymmetrical signal spacing.

Gotta agree with Frits on this one (& others of course ).

[Muhr]

When it comes to gas dynamics and thermodynamics, I tend to treat any twin as two singles; in my experience all gas exchange processes in a twin are identical to those in a single. Engines with 1-in-2 inlet systems (Trabant) and 2-in-1 exhaust systems (BRP-Rotax) excluded of course.


By the way: that Rotax engine could be shoehorned into a Trabant without much effort. Imagine standing at the traffic lights with your little two-stroke car merrily bubbling away, nobody having a clue that instead of 26 HP you now have 165 HP under your right foot .

I had my suspicion that it is the case.
When you have gone too far and standing on idle and not coming from it feel so close yet so far away. My hope is, however, that cylinder "A" will be a little more forgiving then cylinder "B" probably will be.

Rotax engine in a Trabant that would be awesome. Have seen videos on smart cars with Hayabusa engines.

[Nath88]

Excellent lecture from Clint Gray, combining theoretical knowledge and practical thinking. I especially like the simple asymmetrical signal spacing.
Here is some more injection lecture for the Christmas holidays:

EDIT: uploading failed because the file is too big (2793 kB). You might try to find it yourself on the internet.
Search for WO2016193902A2 : Internal combustion engine having two fuel injectors per cylinder and control method therefor.

I believe this is the same patent.
http://www.freepatentsonline.com/20170159598.pdf

Update on my thing:
-I'm overdriving the piezo transducer, they're rated at 15V AC, I'm seeing an output of 50V. The signal diminishes over time, quickly at first, then it settles. Could market it as 'self calibrating', but the better option would be to use a smaller disk to reduce the output.
-The signal to noise ratio is still not that great, and I'm hampered by being fixed to 1 value where the fuel table switch occurs. The ideal switch value varies by RPM.

-I have found that the pipe effect on overall air flow is greater when the throttle is more closed, it's about 2.5x 8000rpm 100% throttle, and about 4x at 0% throttle (by extrapolation). I guess the pipe is providing a bit more intake vacuum, overcoming some of the throttle restriction.
-Richening the air fuel ratio to approx 14.4:1 from 15:1 has stopped the unwanted ARC/HCCI operation at light throttle.
-The next trial will be to use a differential pressure sensor between the intake and the crankcase. I've previously found crankcase vacuum increases with pipe effect, but it's relative to the total pressure in the system, which is influenced by atmospheric pressure and throttle restriction. Accounting for both with differential pressure might give me a usable signal. KTM must be doing something like this, since they are measuring crankcase vacuum.

[Flettner]

I see your water cooled exhaust spigot And raise you.
An ethanol cooled exhaust flange��
Athough it wasn't to cool the exhaust, It was to heat the ethanol. Wrong, don't need to do That.
It did heat the tank up, using the original mechanical injection system I used on the Kawasaki, with a circiting mechanical fuel pump.

[F5 Dave]

Neil I do love your inquisitive mind.
Wish I could get enough sleep to achieve 1/4 what you do.

[TZ350]

I see your water cooled exhaust spigot And raise you.
An ethanol cooled exhaust flange��It did heat the tank up.

Proof it was cooling the gas in the header, very interesting that....

[TZ350]

.
Modified 1978 Suzuki GP100, water cooled, 6 speed, dry sump gearbox, 8 plate clutch and fuel injected. Target is 32 rwhp at 12250 rpm.



The next step in the EFI saga is to detect with a piezoelectric sensor any in cylinder pressure just before exhaust port opening to see if the motor has fired or not.



It was suggested to me that to get a good reading all I would need is a 0.75mm hole in the cylinder wall.



The cylinder casting is very precise, no wasted metal anywhere so it is quite a challenge to find somewhere to drill through without breaking out into the water jacket. It wouldn't do having combustion gases escaping into the cooling water, it would boil up in no time.



I managed to drill a clean 1.53mm hole through the cylinder with no break outs into the water jacket or cylinder head stud hole and the drilled hole came out just above the exhaust port. 1.53 and 1.55mm drills are much easier to work with than a 0.75mm one.

I made this quill with a 1.55 OD, 0.75mm ID tube and to be doubly safe the hole in the cylinder is drilled size for size with the last 5mm of the quill a 0.02mm interference fit in the cylinder wall so the quill is completely sealed in the cylinder at both ends. The quill was a grantee against breaking into the water jacket or a thin or porous patch of casting.

I was finding it challenging figuring out how to get a 0.75mm hole through the cylinder wall that would be reliably leak proof, and I am pretty happy with the way this has worked out.

[chrisc]

I 4 corner seized it. Pretty certain I overheated it which is unsurprising. 26 degrees by 9am, 32 degrees in the shade mid day. Undermaintained cooling system and no temp gauge

Chris, sorry to hear you have had a bit of a nasty off, get well soon. best wishes from Team ESE for a speedy recovery.

Thanks team. Pretty bloody achy still but progressing well. Should be all good and have medical clearance for the nationals. I'm so hyped. I keep waking up at odd hours with racing and bike setup on the mind.

Chris that is both good and bad to hear. Keep blowing into that machine with the floating balls and get those lungs sorted.
And go up a pilot size. Closed throttle is a swine on long tracks.

You're soooo right Dave. I stuffed up not being proactive with setup.

I'll bet they hated you, nothing worse than being beaten by a 50!
You need to get well soon and teach them that lesson again.

So many laughs in the pits. "Is that REALLY a 50?!" Can't wait man.

Chris - missed you again, dammit. At least you'll be moving slow enough for me to catch up and meet you now.

Next racing I'll be doing is round 1 of the nationals, first weekend of Jan at Ruapuna. We'll have a massive field of 125s with our our grid this year and some really solid competition. Come say hey if you're around.

[F5 Dave]

I had about 3 of those Daytona ones. All failed pretty quickly so gave up as it was always pretty stable. . . At least on the last RG engine.

[Flettner]

My metal un printer at work. This is the real valve cover, the other was just a ' test cut'