Aircraft suitable carbs.

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Streffpilot

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Hi, Im wondering if anyone knows what kind of carb that would bolt onto a small block chevy would allow the mixture to be adjusted while in flight. Or if there are any mods to a regular car carb (ie: Holly or such)
 

Dana

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I don't know what's available off the shelf, but a relatively simple mod is to port manifold vacuum to the float bow... jet a bit on the rich side to begin with, then add vacuum to lean it out.

-Dana

Space isn't remote at all. It's only an hours drive away if your car could go straight upwards.
 

Dan Thomas

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Sep 17, 2008
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RAF's gyrocopter Subaru conversion used a Holley carb with a mixture control plate between the bowl and carb body. The various channels were drilled through the plate, and one of them was the delivery from the main jet. Another drilling down through the plate from the top held a small shaft with a flat milled onto it that acted as a mixture control. It was really abrupt and didn't spread the mixture variation over much control travel; I machined a taper onto the end of the shaft to give better control. And then it turned out that the Subaru did not want to be leaned much. It burned a valve when I did so, and RAF indicated that they found it similarly useless.

Dan
 

Max Torque

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Arizona/Alaska/several nasty places around the glo
You can use a Holley carb. Tom McNeilly makes a leaning block for it. Are you using a Belted Air Power small block Chevy set up?

Dan, did you use one of Tom McNeilly's leaning blocks on the Subaru? What model Holley carb was it? Interesting to note that the engine didn't need to be leaned much. At what altitudes were you/RAF flying?

Thanks,
Tom
 

Streffpilot

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I actually plan on running direct drive with a forged crank, running a 383 stroker. Eventually, an aluminum block would be nice, but for the proving phase of testing, I will be using an iron block for economic reasons. I have been reading much about how the airboat community runs their props direct drive, and that got me to thinking, so we will see how it works.
 

Dan Thomas

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You can use a Holley carb. Tom McNeilly makes a leaning block for it. Are you using a Belted Air Power small block Chevy set up?

Dan, did you use one of Tom McNeilly's leaning blocks on the Subaru? What model Holley carb was it? Interesting to note that the engine didn't need to be leaned much. At what altitudes were you/RAF flying?

Thanks,
Tom
The block came with the carb, which came with the conversion. Can't remember the carb model but it was a two-barrel unit. I would carefully lean in cruise; when I did a max-power short-field takeoff, standard procedure for which is to lean to max RPM, it burned an exhaust valve before I got to 100 feet altitude. The valves in the Subaru are slender little things compared to the massive sodium-cooled valves found in a Lycoming, which is fine when you have a computer controlling the mixture for various power settings. Doesn't work so well when one tries to operate it like a Lycoming or Continental.

Dan
 

Max Torque

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Dec 16, 2011
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Arizona/Alaska/several nasty places around the glo
Thanks Dan.


The block came with the carb, which came with the conversion. Can't remember the carb model but it was a two-barrel unit. I would carefully lean in cruise; when I did a max-power short-field takeoff, standard procedure for which is to lean to max RPM, it burned an exhaust valve before I got to 100 feet altitude. The valves in the Subaru are slender little things compared to the massive sodium-cooled valves found in a Lycoming, which is fine when you have a computer controlling the mixture for various power settings. Doesn't work so well when one tries to operate it like a Lycoming or Continental.

Dan
 

cklskypilot

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Nov 13, 2011
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estacada oregon
Good Morning I use to crew a superpro\comp elemintor team. we used a flying toilet fuel injection system. I have seen these used in the aircraft field. both on cross country planes and the aerobatic field. easy to ajust and light weight. I think that Mr. Crowler used them on a exp. aircraft engine package If I remember right he was getting 700 hp. out of a s\b chevy.

Happy flying Chuck
 

slociviccoupe

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Apr 1, 2011
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Location
Palm Bay Fl.
or run the mercruiser fuel injection for a small block chevy. very simple and 100% complete bolt on. uses a map and tps based speed density system. intake air and coolant temp. along with a crank trigger. still uses a hei distributor. fuel system is already there too with a small header tank with the high pressure fuel pump. no carb needed. just a thought. also with a mercruiser or other scanner it is programable and all sensors can be monitored.

there is the oem mercruiser and there is also the high performance arizona speed and marine products.
 
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