ESE's works engine tuner

[Frits Overmars]

These electronic manometers coupled with a rotary encoder look very tempting. http://cavanaughracing.com/cdproflow.html

Nice stuff; it will ease operating a conventional flow bench.
It won't however correct the shortcomings of a conventional flow bench: much lower pressures and temperatures than in a firing engine, and no pulsed flow.

[marsheng]

haufen let me ask something about the extension. on each end where its machined down to fit inside the arm. the machining will produce sharp inner corners. do you think i should make these inner corners have a small radius instead or it isnt critical ? i always thought a crack can form at sharp corner but maybe this situation isnt a big deal. cheers mate

Remember that aly looses a lot of strength when welded. It softenes quite a bit. Some structural bits are heat treated to get the strength back.

[MattPatterson]

Hi Guys,

This is my first post here. Spent many an evening trawling through this thread. Have to say, the knowledge and tips that have been shared is astonishing, and long may it continue.

Great to see the projects people are working on too.

The only trouble is that I should be working and not reading this thread, but there's so much to learn that work will have to take a back seat until I'm all up to date. And as it's 8pm here in Thailand, I think that I'm allowed a tea break.

Cheers.

[breezy]

Has anyone ever heard of a ' lean burning 2 stroke engine"... past or present? i read recently about 4 stroke lean burners wondered if it had been tried on a 2 stroke...

[philou]

Informations for flowbench => http://www.hpt-sport.us/goflow.htm

[Nath88]

Has anyone ever heard of a ' lean burning 2 stroke engine"... past or present? i read recently about 4 stroke lean burners wondered if it had been tried on a 2 stroke...

I've run my injected YZ250 at more than 19:1 ratio (off the scale on the lambda sensor) on highway cruise, about 5-10% throttle. Injection rate of 2L/100km. Ran smoothly with no misfire for 8 seconds until power started to roll off, throttle response was very weak. After that it ran fine, piston and plug looked normal. I found some info from light aircraft people talking about 'lean of peak' operation on 2 strokes, however they tend to be a bit more conservative. Also the cruise load for a plane is probably a higher than a bike. I think lean burn could work for light throttle, fuel economy is impressive if it can be sustained.

[Haufen]

Has anyone ever heard of a ' lean burning 2 stroke engine"... past or present? i read recently about 4 stroke lean burners wondered if it had been tried on a 2 stroke...

HCCI for example is a lean burn combustion process. Also any Diesel is typically running with excess air.

[Lightbulb]

On models they had lean burning glow plug engines to more range. So the fuel had no methanol in it. But would fail a plug if it truly did run lean. I developed a squish band toroidal head that could run lean without failing the glow plug. The result of the model engines running lean was a big end on the rod bush failing. It may have still worked if it had a miniature needle roller set up like some have made. I never have gone down that track yet with the model engines. But with hcci on the horizon that maybe the missing link.

[lodgernz]

Hi Guys,
This is my first post here. Spent many an evening trawling through this thread. Have to say, the knowledge and tips that have been shared is astonishing, and long may it continue.
Great to see the projects people are working on too.
The only trouble is that I should be working and not reading this thread, but there's so much to learn that work will have to take a back seat until I'm all up to date. And as it's 8pm here in Thailand, I think that I'm allowed a tea break.
Cheers.

Welcome Matt (no pun intended). I take it that you are the Matt Patterson of Tyga Thailand?

[MattPatterson]

Welcome Matt (no pun intended). I take it that you are the Matt Patterson of Tyga Thailand?

Yep, that's me.

[TZ350]

The transfers were flowed with the piston in 4 positions 25% open, 50%, 75% and fully open

Very interesting, is that 25% of window area or 25% crankshaft degrees of opening? Thanks.

[jamathi]

Very interesting, is that 25% of window area or 25% crankshaft degrees of opening? Thanks.

25% of window area.

[jamathi]

Nice stuff; it will ease operating a conventional flow bench.
It won't however correct the shortcomings of a conventional flow bench: much lower pressures and temperatures than in a firing engine, and no pulsed flow.

I never missed higher pressures or pulsing flow.....
Still not see the necessity.
And the engine does that already, measure the air consumption if you like to know that.

[polinizei]

I tried that 90% exhaust mod a couple days ago. Its a 135cc engine with 58 x 51mm, single exhaust duct, 30mm carb and fan cooled. The rear wheel power is about 30 HP.
The mod brought no power gain, but had more power fading (2-3HP) due heating the cylinder much more.
After removing the sheetmetal part, the power characteristics was back.

But I have to say: it worked well in engmod :-)


It think I should go the old fashioned way and enlarge the duct in little steps...

[Pursang]

Its a 135cc engine with 58 x 51mm, single exhaust duct, 30mm carb and fan cooled. The rear wheel power is about 30 HP....

30RWHP That sounds wonderful, I need some of that, will you please show what the transfer ports look like?

EDIT!! That's OK I think I've found it.



Cheers, Daryl