The Stovebolt Site Forums The Shop Area Engine Shop Airplane Carb on a truck?

Has anyone done or heard of this? I live near the mountains and it would be great to be able to change the mixture like on and airplane. Just curious if it would work or not.

Now ya wanna fly..???? LOL..yup used to live at altitude.. uhhhhhhhh dunno bout airplane carbs tho..??? uhhhhh again.. altitude usually changes more the air mixtures...less air at altitude...you can compensate tho for that with timing..if i remember right ya advance timing 2 degrees for each 1000 foot.. smaller jets help the higher ya go too.. as for adjustable..?? the best answer would be a turbo...then ya dont hafta worry bout no stinkin altitude....hehehehe

Been there, tried that- - - - - -didn't work! I was attempting to meter liquid Propane through an aircraft-type pressure carburetor. You MIGHT get away with gasoline, if you supply enough fuel pressure (at least 25 PSI). The altitude-compensating function leans the carb out at high altitude to compensate for the less-dense air up there. I don't know if the carb would be sensitive enough to adjust for sea level VS. Denver @ 5,000 feet, but it might work on Sonora Pass at 10,600 feet. Good luck if you try it. The carb would need to be calibrated for an engine approximately the same CID as the truck.
Jerry

Thanks guys, I knew I'd get a chuckle out of some of ya. Just always wondered about it. I guess I could just put on a fuel injection system w/ twin turbos

I tried to think of a downdraft aircraft carb but the only ones I could think of belong on the larger radials and V-12s with throats I could stick my whole shoe in and around 3 inch venturies. There is the Lycoming O-235 which would have about the right size carb but it's updraft.

If I remember it right there was a Stromberg or Carter carb with adjustible main jet?

Works not automatic, but can be bolted rigt on without modifications.

Frank

Think about the operating conditions of piston aircraft engines,even during cruising,the engine is devoloping 70-80 percent of it's full power rating which is at a low RPM range as compared to automotive engines.And I would imagine any aircraft carb parts are brutally expensive.
When engines such as Corvair,Suburu etc are converted for experimental aircraft,what carb do they use?
You might better take a look at variable venturi vacuum controlled carburetors(constant velocity) such as SU,or Japanese bike carbs.

I suspose as long as you dont decide to install wings on the truck I will still think of you as a man with a sane mind,,,,,well maybe

Joker, Sanity is boring. You should know that

Adjustable main jets are available for Holley 94 carburators (The 3 bolt 2bbl flathead kind). They are adaptable to a 1bbl manifold. You can order them from http://www.vintagespeed.com/
I have a set, but I have not tried them yet. They are an adjustable needle valve that pokes into the main jets. The adjustment screws stick right out the side of the carburator so you can futz with them without even taking off the air cleaner.

Well he's a 'Shipwright' wantin to marry an 'Airplane' to a 'Stovebolt'. Joker, he may be sane, but certainly is confused at the same time. Or just multitasking. I know rdbates mentioned "There is the Lycoming O-235 which would have about the right size carb but it's updraft. ". Well, there are some aerobatic planes using O-235's so that might not be an issue, right?

Rance (talking out the side of my head again)

Well, I talked to the Guru, Mr Carbking today, and he says there's a Stromberg & a Zenith that have external knobs for changing the mixture. Might do duals if he or I can find a matched pair.
This idea cam about on my journey to the Midwest All Truck Nationals in Kansas City. On the way there it ran better and better as I the miles went on & the altitude dropped. When I got to KC, the truck ran like a scared rabbit. It's a little rich here in Denver but just right @ sea level. I'd hate to lean the jets for this alt. & then be too lean when I went East. Can't ya burn up pistons that way? I could just change jets or metering rods when I know I'm gonna go to a different Alt. But what a PITA. Sounds like its gonna be expensive to do but a cool novelty none the less. Dunno if I'll do it or not but I'll keep posting if I do. Fun to think about & type about though. At the very least it gave some of you something to chuckle @. As for my sanity, well, I hang out here don't I? :p

I think you should do it , then you can ship me yor carter yf,,,,,,,,,,,,,,,,,,,,so you think sanity has something to do with hanging around here,huh that my friend makes you a very smart guy...Fred

Hey Shipwright - Sorry about that intake on Ebay - those airplane carbs won't fit an edelbrock anyway I hear what you mean about the altidude. My truck lived most it's life at 7k in Evanston, Wy. Here in Seattle which is basically sea level, it runs like it has a new motor compared to there. I've experienced that with most my cars going from there to here.

Altidude Isn't that a guy that lives in SLC and works at a ski resort?

Aircraft carbs don't have accelerator pumps, which makes them pretty well useless in a car.

I helped install a VW engine in a plane. It didn't have a carb - used a throttle body instead.

Some aircraft carbs have accelerator pumps. I flew a Piper Apache that we primed with the throttles. As far as running too lean, install a 6 channel EGT and you can see what each hole is doing.

A couple of comments on this subject:

Shipwright and I did have a conversation concerning the Stromberg and Zenith carbs with adjustable jets. By the way, Shipwright, there are many others with adjustable jets ie Marvel, Tillotson, Rayfield, Mallory, and probably more; but these carbs for the most part were sold to customers too frugal to purchase a repair kit for the original carb, so will not discuss them here. Carter also made a carb with adjustable main metering jet, but it is not one we recommend.

The whole subject of adjustable main jets is largely misunderstood; in fact the term itself is misleading. In general, when a carburetor is fitted from the factory with an adjustable main metering jet, the design is to install a larger than stock FIXED main metering jet and an adjuster which will restrict the fuel flow (there are other methods). There are some either "less than knowledgable" or "less than ethical" individuals that sell an aftermarket adjustor, which will do nothing for a richer mixture unless the fixed main metering jet is changed.

Generally (there are exceptions), the adjustable jets came from the factory on "universal, replacement" carburetors. Taking an adjustor from one of these, and applying it to a carb not designed for the adjustor doesn't necessarily work.

The one barrel carbs with the adjustable main metering system which we recommend (we have some of the others, should any wish to disregard this advice LOL) would be the Stromberg "B" series (at least one company made a good "B" series carb LOL) and the Zenith 28 and 228 series carbs. These come in two different physical sizes: S.A.E. size 2 (nominal 1 7/16 bore, 2 11/16 center to center) and S.A.E. size 3 (nominal 1 5/8 bore, 2 15/16 center to center). Each size comes in at least 2 different internal venturi size, and several different configurations; so one MUST be careful when selecting these to match them for use on a multiple carb setup.

As to aircraft carburetors; as I do not have FAA certification, I will NOT discuss aircraft carburetors other than the following: (A) we have one of the worlds largest librarys of USA produced aircraft carburetor reference books (some internal manufacturer items which are one-of-a-kind) for sale; and (B) typically, parts for aircraft carburetors seem to be priced at approximately 10 to 20 times their comparable automobile counterpart.

Jon.

Thanks for the Info Jon. Your knowledge and willingness to share it is much appreciated.