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HACman Mixture Control Kit


Dale
 

Don't know if the group is aware of this:

http://gsatech.store/hacman-mixture-control-kit/

I thought they were out of business ...

Dale


craig powell
 

I was the first one to use this new model 18 months ago on my Gen 4 as a beta unit. Needles to say I had some problems at first in the way it was supposed to work. After 3 months going back and forth with the owner of HACMan on a faulty design on the needle valve and how It was hooked up, the issues were resolved and the manual now incorporates a different way to work with Jabriu engines.


On Mar 23, 2021, at 8:10 PM, Dale via groups.io <daleandee@...> wrote:

Don't know if the group is aware of this:

http://gsatech.store/hacman-mixture-control-kit/

I thought they were out of business ...

Dale


jabcamit@...
 

I think a better  and cheaper (around $50) solution would be to  make a simple electric motor driven  centrifugal vacuum pump (vacuum proportional to  motor speed, knob on control panel to control motor speed).   An added advantage of this set up is that it could be made self tuning (press a button and it  increases leaning  until  EGTs  or rpms dip a defined  amount). Also it could turn off  automatically when WOT is engaged, (microswitch on throttle lever).

BobP


John Miller
 

Mine was home built and cost under $100. Veryu simple hookup. Of course I don't have the knob showing which way to turn for lean, but that's easy. Left lean...right rich.

The most expensive part is the laboratory  35 turn valve. The rest was hoses.

Works great when the Bing auto altitude adjust gives out around 7500 feet.

Alt altitude say 10,000 MSL and leaned out I burn only 2.8 GPH in my 2200.

John M


glen english LIST
 

I have a few different vaccuum pumps I got from china for my (robot) vacuum pickups. They were small,light and $10. However if you can get something from a reputable mfr, I''d suggest it. Or use a pressure pump and a vaccuum venturi.......

I want to make my closed loop - vac pump, diff pressure sensor/ lambda sensor.

However, humans make pretty good feedback loops ! So Bob's and john's idea is perfect.

And lambda sensors clog up quickly with leaded fuel...

On 24/03/2021 11:46 pm, jabcamit@panth.co.uk wrote:
I think a better  and cheaper (around $50) solution would be to make a simple electric motor driven  centrifugal vacuum pump (vacuum proportional to  motor speed, knob on control panel to control motor speed).   An added advantage of this set up is that it could be made self tuning (press a button and it  increases leaning  until  EGTs  or rpms dip a defined  amount). Also it could turn off  automatically when WOT is engaged, (microswitch on throttle lever).

BobP


John Miller
 

I use the fuel primer input on the carb for vacuum source.

No need for a pump.

John M


jabcamit@...
 

Not all vacuum pumps are the  same. For best design you need a pump that produces a precise and predictable pressure differential  (as opposed to defined volumetric pumping) proportional to the control knob (or whatever) position. 

I think Hackman type devices are air displacement? If so  they are not ideal.

BobP


John Miller
 

Since Hackman devices depend on vacuum you have to be aware that if you have it leaned at cruise and then sudeenly reduce you RPM the engine could die.

Also, with normal leaning (Continental) at a high altitude airport you can rev the engine and set the mixture for best RPM and then taxi to the runway for take off.

With the vacuum unit I have to pull out on the runway, hold the brakes and and run to full throttle and then lean for best RPM.

Upon departing from a 6700 MSL airport I see an extra 40-50 RPM which is a big help on climb out.

John M