Where Fuel Meets Air

Spark-ignition reciprocating engines require that fuel be mixed with air in the proper proportion to support efficient combustion, a process known as "fuel metering." Maintenance expert Mike Busch discusses various methods of accomplishing this. SavvyAviation offers Professional Maintenance Services to owners of General Aviation aircraft, such as: Savvy Mx (Professional Maintenance Management), Savvy QA (Expert Consulting), Savvy Prebuy, SavvyAnalysis (Engine Data Analysis) and Breakdown Assistance. For more information, visit us at savvyaviation.com. This webinar was hosted by the Experimental Aircraft Association (EAA).

[@trilomann]

These webinars are worth gold !!!! Thanks for sharing Mike.

[@charosenz]

Excellent in depth view of the MS carb. Especailly for people who are new to carbs. (Thanks for not adding annoying music!)

[@michaelclements4664]

Regarding accelerator pumps: Bush doesn't mention another reason for these. When the throttle is suddenly opened, Bernoulli's law says velocity through the throttle briefly slows down, which causes a pressure increase, which draws less fuel, which leans the air-fuel ratio. This happens only briefly, until the engine speeds up, increasing airflow. Thus, suddenly opening the throttle causes a brief lean condition. An accelerator pump squirts a little fuel to counteract this.

[@sebastianruffer5184]

Thanks for sharing your knowledge in all those webinars. Making it available is a HUGE contribution to GA safety. Again THANK YOU, Mike!

[@brianferrero9544]

Great videos! I'm currently learning about aviation fuel metering, including pressure carbs. Seems like there are many variations . You have a mash-up of two different diagrams: the diagram of the PS 5, but the image next to it is not a PS 5, and is a different model/setup/arrangement. Dale Crane, Jeppesen, and the 8083-32 talks about the PS 5 specifically. The 8083-32 also describes what looks to be an amalgamation of a generic pressure carburetor, not indicating the specific model. The diagram you have (right side of screen), and the design you talk about, is an unspecified model. It seems closer to a PD or PT serries model. Thanks for these great videos. Tons of great information! And really enjoyed the Q&A''s on this episode.

[@gmcjetpilot]

I just found this channel. I've learned so much from these webinars. I knew a lot of it but I'm just getting more in-depth knowledge than I ever had before. thanks.

[@craigcarpenter6541]

Great description of the different systems.... Glad I watched this one....

[@jjohnston94]

You know what would be a great addition to these vids? It'd be a lot of work on your part, granted, but a timestamp for each question so a viewer can click right to one he may be interested in.

[@RD2564]

You did a nice job on the Stromberg Bendix pressure carburetor my friend, thanks for explaining it for me. I understand venturis, dynamic vs. static pressure, and control valve theory, so I was able to fill in the areas you didn't cover in depth.

[@azarpour]

This was an outstanding presentation, Mike! Thank you for such an amazing job!

[@davidwallace5738]

Outstanding video sir!Thank you!

[@rigsontejada7762]

Literally passing my trade program because of this guy. Thanks for your work sir!

[@Gamemaster0225]

Same

[@Jxcobdy]

You’re short rigs

[@deewaldron7062]

Thanks for this Mike! I've been using it in class to teach my A&P students for a while now. Do you still own that 310?

[@troyball6623]

If the auxiliary fuel pump pressure is higher that the engine mechanical pump, the higher secondary pump pressure can push past the needle and seat flooding the fuel bowl cutting the engine.

[@joaovasconcelos404]

Eu gostaria que tivesse legendas para esses artigos sobre motores de avião. Obrigado

[@davidfitzpatrick7466]

To Mike or anyone that follows this channel, did Mike ever do the webinar on diesels? I'd love to hear that one.

[@VERANTESDEVOLAR]

Aweesome webinar! THanks for sharing this quality of information !!! SALUDOS from santiago de Chile!

[@troyball6623]

I have a question, if a carbureted engine was inverted, what happens with the float bowl in the carburettor ? Does it then try to fill the fuel bowl because the needle and seat would be open when inverted unable to cut fuel off ?

[@troyball6623]

Do aircraft run a water separator on the fuel system ?

[@Rwalt61]

I made a lot of extra money when I was younger, rebuilding carburetors for frends and family members. The biggest things you would have to watch out for is all the minute metering passages that easily got gunk and debris in them. And all the gaskets and seals that would dry up and leak.

[@alaskanalain]

I wish I was too rich to burn

[@karga2tilki]

great! Thank you Sir! But change your dentist.. ;-)