ESE's works engine tuner

[Frits Overmars]

... So they achieved HCCI combustion up to 16 bar BMEP on a 4-stroke engine charged to 3bar absolute pressure. So that would be 8 bar BMEP on a two-stroke engine firing every revolution and charged to 3bar absolute pressure.
With an exhaust pipe only, maximum charging is at about 1,5 bar.

Where did you find that figure Haufen? The Aprilia RSW and RSA reached a cylinder pressure at exhaust closure of nearly 2.7 bar abs.

[MotleyCrue]

Where did you find that figure Haufen? The Aprilia RSW and RSA reached a cylinder pressure at exhaust closure of nearly 2.7 bar abs.

I didnt read the article too closely so far but if the 3 bar was for an auto OEM 4 stroke then the intake valve closes a lot sooner than the exhaust closes on a 2 stroke race engine so a 3 bar pressurized intake auto 4 stroke would have more than 2.7 bar pressure by the time the piston got up all the way to 80 BTDC. Exactly how much I dont know but maybe 6 bar I suppose. Not sure how 16 bar 4 stroke equates to an 8 bar 2 stroke though both having the same boost??

[MotleyCrue]

You can get a big boost in top end power by cutting the piston skirts short on the Ex side.
This creates havoc with the jetting, but once sorted it does work well.

Wobbly, do you mean cut the skirt short enough that the crankcase is connected to the exhaust port when the piston is somewhere near TDC. If so about how many degrees of duration would one shoot for as a good starting point ? I might give it a try, pistons are fairly cheap.

[jonny quest]

Wobbly, that's how I learned 2 stroke pipe building on snowmobiles. There was many a time the 2into1 outperformed individual pipes. You could be right though about 200 ex helping that.

[breezy]

Wobbly, do you mean cut the skirt short enough that the crankcase is connected to the exhaust port when the piston is somewhere near TDC. If so about how many degrees of duration would one shoot for as a good starting point ? I might give it a try, pistons are fairly cheap.

careful!! the exhaust gas temp could dry out the big end bearing...

[Flettner]

https://youtu.be/vVnOM_JZt9A


HCCI in action

The link, it' not working is it?

Just google this Lohmann Fahrrad Hilfsmotor Start durch Anwärmen

You will note that heat in the cylinder / head is nessasary and no sparkplug!

18cc ?

Can you see Ryger in there?

[husaberg]

https://youtu.be/vVnOM_JZt9A

HCCI in action

Mr Frits did mention a smaller radiator.............

[TZ350]

... http://www.highwaymanbikes.com/ I have linked some of his work before.

This is a really interesting must see place to explore.

[tjbw]

https://youtu.be/vVnOM_JZt9A


HCCI in action

The link, it' not working is it?

Just google this Lohmann Fahrrad Hilfsmotor Start durch Anwärmen

It's working, thanks. Looks like he has an exhaust leak.

[41juergen]

Attachment 317534

No sorry, but under "Thread Tools" which is near the top right hand side of the page, you can "View Thread Images" and sort them into 70 per page. When you find an interesting image click on the N/A sign to see the post, there are more than 7,000 images.

When I was playing with EFI I did use a A/F meter but with a 2T there are traps as the A/F reading is seemingly rich when the trapping efficiency is not good, like when you are moving away from peak torque or well out of the power band.

The A/F meter accuracy seemed at its best when the rpm was at peak torque, every where else it indicated varying degrees of rich but was not. Frits put me on to this, the indicated richness was just air/fuel being blown through the exhaust port and lost down the pipe the remaining air/fuel that got trapped in the cylinder burnt correctly, all the air/fuel was of the correct strength for good combustion just some was not trapped and consequently lost and looked to the meter like the engine was running rich when in fact it was not.

Thank's for the feedback TeeZee!
May be than another question to the experts here: how can the fueling be tweaked with the main air jet? The tests I made showed the smaller the air jet, the smaller also the main jet needs to be (of course ). And the smaller the air jet the stronger the negative pressure signal at the needle jet is... But what do I need to do when the A/F at the end of the power band goes significant leaner than in the power band (assuming that here the reading might be not too wrong)? Will a significant larger air jet together with a corresponding bigger main jet the way to go? I know that a power jet can do that, but in the power band the A/F ratio and the exhaust temps are fine.... Or is there also a reason that the lamba meter shows at the end of the power band very wrong readings?

[husaberg]

Thank's for the feedback TeeZee!
May be than another question to the experts here: how can the fueling be tweaked with the main air jet? The tests I made showed the smaller the air jet, the smaller also the main jet needs to be (of course ). And the smaller the air jet the stronger the negative pressure signal at the needle jet is... But what do I need to do when the A/F at the end of the power band goes significant leaner than in the power band (assuming that here the reading might be not too wrong)? Will a significant larger air jet together with a corresponding bigger main jet the way to go? I know that a power jet can do that, but in the power band the A/F ratio and the exhaust temps are fine.... Or is there also a reason that the lamba meter shows at the end of the power band very wrong readings?

I am not Rob (TZ350)but Robinson covered it.
Remember carbs have over lapping circuits the air jet is used to compensate for the rate at which the fuelling of the main circuit is controlled by an increase in high speed airflow.

[TZ350]

Thanks Husa for the pictures of the fueling curve, I hunted high and low but could not find them. ...

[husaberg]

Thanks Husa for the pictures of the fueling curve, I hunted high and low but could not find them. ...

I can't figure out how to move them from the album back without posting them as images rather than attachments though.
All (well most) the carb stuff I have posted is here.
http://www.kiwibiker.co.nz/forums/al...p?albumid=4844

Exhausts stuff from the thread is here
http://www.kiwibiker.co.nz/forums/al...p?albumid=4854
Aprilia stuff from all over the web is here
http://www.kiwibiker.co.nz/forums/al...p?albumid=4839
Frits Overmars home phone number and bank account details are here
http://41.media.tumblr.com/227f11a82...g3vgo1_400.jpg

[41juergen]

perfect, thank's a lot Husa. Some of the stuff I already know, but the Robinson book isn't in my shelf, so more to learn...

[Frits Overmars]

Mr Frits did mention a smaller radiator.............

My grandfather is in no way involved, Husa. In other words: drop the Mr .

Frits Overmars home phone number and bank account details are here
http://41.media.tumblr.com/227f11a82...g3vgo1_400.jpg

Would you please remove the phone number Husa? You can leave my bank account details. Thank you.

EDIT: Sh*t ! That is the number of my swiss account. Please remove immediately!