ESE's works engine tuner

[TZ350]

... I love the side resonant ( thats what Prof Blair calls that setup in his books ) "flute" idea -

Great minds think alike ... .... right.

[Ocean1]

You could use the same idea by uncovering staggered holes as the outer rotates, without changing the length.

Or a slot, (stepless).

[wobbly]

Then go another step, and I bet you a free blowy that a progressively varying slot width is what is needed to get the the optimum effect at differing rpm.

[Ocean1]

Then go another step, and I bet you a free blowy that a progressively varying slot width is what is needed to get the the optimum effect at differing rpm.

A step further: make the moving element a sleave with a radial slot, the intake tract with an axial slot of varying width. It means you can vary the cross sectional area of the bleed aperature to exactly suit the revs (+ and -) while allowing the sleave movement to be linear.

[Yow Ling]

A step further: make the moving element a sleave with a radial slot, the intake tract with an axial slot of varying width. It means you can vary the cross sectional area of the bleed aperature to exactly suit the revs (+ and -) while allowing the sleave movement to be linear.

So long as it has USB and a Facebook interface it will be great

[jasonu]

Then go another step, and I bet you a free blowy that a progressively varying slot width is what is needed to get the the optimum effect at differing rpm.

I'd want to know who the free blowy is coming from BEFORE accepting that wager...

[TZ350]

now could there be any benefit in adding a variable tuned length to the bellmouth of my pumper carb? Narrr probably not! ... why would someone want a massive ramming effect from the inlet tract through out the power range?

[Grumph]

now could there be any benefit in adding a variable tuned length to the bellmouth of my pumper carb? Narrr probably not! ... why would someone want a massive ramming effect from the inlet tract through out the power range?

Am I the lone voice here who says you're not lengthening the inlet tract with that huge carb extension ? Factories deliberately make the OD of the bellmouth area - where a hose to an aircleaner would attatch, and where your extension attatches - large enough to avoid any entry flow effects when there is a hose or similar on there. If your bellmouth was the same ID as the carb bore then yes you're lengthening the tract....you're not !

What you are doing as has already been said is adding a short resonant chamber onto the entry of the carb. Yes, a heimholtz resonator.

IMO you got lucky when you saw a cleaning up of the carburation over a limited range...it could just as easily have gone the other way.

Normally when tuning 4 strokes you'd change needles to achieve the same result while leaving the inlet tract length correct for max power rpm.

[bucketracer]

Am I the lone voice here who says you're not lengthening the inlet tract with that huge carb extension ? - If your bellmouth was the same ID as the carb bore then yes you're lengthening the tract....you're not !

What is the function of a velocity stack on an Amal carb, they are bigger at the carb end than the carb throat.

Normally when tuning 4 strokes you'd change needles to achieve the same result while leaving the inlet tract length correct for max power rpm.

They will have tried that. Anyway why leave it "correct for max power" when you can vary it for better performance throughout the range?

IMO you got lucky when you saw a cleaning up of the carburation over a limited range...it could just as easily have gone the other way.

Didn't so its a useful technique ...

What you are doing as has already been said is adding a short resonant chamber onto the entry of the carb. Yes, a heimholtz resonator.

Yes a series resonant chamber, TeeZee has been talking about that. He thinks more experimenting is called for ...

A series resonant chamber in sync with and feeding the inlet tract proper can't be a bad thing can it?

[Grumph]

What is the function of a velocity stack on an Amal carb, they are bigger at the carb end than the carb throat.

The function is to clean up airflow at the entry - no more than that as there is a step remaining at the entry. The real ones are the same bore as the carb. Most are cosmetic.



They will have tried that.

Not stated...and needles are often not available for OE carbs...



Didn't so its a useful technique ...

In some - very closely defined, circumstances



Yes a series resonant chamber, TeeZee has been talking about that. He thinks more experimenting is called for ...

So do all the serious researchers

[bucketracer]

""The function is to clean up airflow at the entry - no more than that as there is a step remaining at the entry.""

The cleaning up of the air flow is what TeeZee thinks is the reason that the longer inlet with the hole made better power than the open carb and is also why he can flow quite a bit of air through a 24mm venture when its fitted behind the slide of a bigger carb. He thinks the bell mouth and first part of the carb gets the air flowing in the right direction.

[bucketracer]

So do all the serious researchers

Grumph maybe they could post something enlightening themselves ... by any chance, do you see yourself as a researcher too?

[Moooools]

Well here is how I would do it. Even though I may be pissing into the wind a bit.

My theory: isolate most of the spring action from the straight shot of incoming air.
THoughts

(sorry for continuing on with this 4 stroke nonsense)

[Kickaha]

(sorry for continuing on with this 4 stroke nonsense)

There is a four stroke tuning thread but none has posted since 2009 http://www.kiwibiker.co.nz/forums/sh...ormance-tuning

I think they're all to busy out riding their bikes and winning races than typing out hundreds of page of crap on how to make your bikes go fast

[TZ350]

I think they're all to busy out riding their bikes and winning races than typing out hundreds of page of crap on how to make your bikes go fast

Its not every day I agree with Kickaha about 4-Strokes and there value to mankind, but what he said could be true .....