I recently bought a 79 F150 with a 302 in it (I dont know which year 302... see this thread for details How to figure out which engine - Ford Truck Enthusiasts Forums ) The engine doesnt seem to have any work done to it except for an Edlebrock 650 carb on it. It also has straight pipes on it from the headers.


It was running ok when I got it, but would sputter and hesitate when you stuck it in 3rd and if you had your foot on the clutch at idle it would some times stall.

I took the fuel filter out and it was pretty dirty so replaced it. When I started it again it ran super rough and would backfire if you touched the throttle. The fumes also stunk like gas.

I had a buddy of mine look at it and he said it could be that the carb in it now is too much for the stock engine. He said that if I put a stock carb on it that I would probably see it run better. Any truth to this? I'm 100% a newb when it comes to carburetors on engines.

 

A 650's too big for a normally-driven truck. That might cause some problems, but not like you're describing. What RPM does it idle at? Stuttering at idle could be carb related, but I'm confused about when it goes into third. Let's see what others say. Welcome aboard.

 

I have no idea what rpm its at, the truck doesnt have a tach on it. That will be the first thing I do pay day this Friday.

I dont know if this matters, but its got 4.10s in it and 35 inch tires.

 

Your buddy is correct. A 650cfm carburetor is way too big for a 302 engine. A smaller carburetor will give you much better throttle response, gas mileage, and maybe even better performance than what you have.

For a replacement, the Edelbrock 1406 500cfm carburetor is a good size, as well as the Holley Avenger 570cfm.

 

So if I put a smaller carb on, do you think it would fix the stalling problem?

I dont know if I explained that well enough before. If i'm driving, and come up to a light or stop sign and push in the clutch as I'm stopping, it just stalls.

 

83-85 5.0 Mustangs came with a 600cfm holley/motorcraft 4bbl, but they had MUCH better heads and cam (if its a 79 vintage 302).........450/500 cfm is all you need, heck, I would say a 390cfm Holley 4bbl would be ideal.

 

Maybe even a 500 holley two barrel. Then you would have only primarys, and it would all be controlled by your foot. Not sure about how an edelbrock works exactly, but with a light foot, if it does what your saying, it might be getting too much air and not enough fuel. Holleys open the primarys only, and then use vacuum to open the secondarys, as the vehicle needs it. You may have something plugging up the jets.

 

Sounds like i'm going to need to look for a new carb.

Next problem, finding out which engine I have.

https://www.ford-trucks.com/forums/1...ch-engine.html

 

The 1406 is a 600 CFM carburetor... the 1403 is a manual choke 500 CFM carb.

So, the carb is a Thunder series 1805/1806?

Either way it would be good to pop the top and check what jets are installed and also peek under the piston covers and see what rods and springs are installed. If the carb is jetted way rich or way lean you'll have problems, or in the case of the wrong springs stumbling and hesitation during acceleration and cruise.

Josh

 

Not hijacking the thread, just borrowing it a little. I have an opportunity to buy an edelbrock 650 for my stock 460. Is this too much carb or will it be ok? I am rebuilding the 4300 that was on it right now but people are saying they are a pretty sorry carb all around. A little help please.

 

What you need to do is do the math on a carb calculator. I would think a 650 is allright on a 460, but do look at the thunder series, and carter afb. I know of some problems with the new cheaper edelbrock carbs. Here is a calculator for you. TCI® - Sorry...

 

No it's not to big. I run an old carter afb 750 on mine, engine is not stock mind you but a 650 shouldn't be to much for a stock one.

 

Thanks for the information. I did the calculator and saved the website. It is pretty handy. Thanks again.

 

I would think if you can afford it a new carb would be worth it not shure but the fact that it looks like the carb was installed with RVT instead of a gasket does not inspire a whole lot of confidence in the P.O.'s mechanical ability.
John

 

Just a side comment. Selling car parts since 1978, i have a long list of idiot customer ideas and fetishes if you will.

1) Every chevy customer has a 'vortec.' I dont care if he is driving a 85 celebrity or a 90 model cavalier, the dang thing is a vortec.
2) "All chevy V-8s are the same motors." ex. the new 5.3 V-8 Chevy, cant tell you how many times i have had customers come in and call it a 327... Chevy hasnt made a 327 since about...oh 1968!!!!!!
3) Every chevy customer with a 350 wants the biggest dang carb they can afford to bolt to the manifold, an "1180 double pumper" etc. They dont have a damn clue what they are talking about they just bench race with their drunken retarded buds and have developed a total mythology of stupid ideas. They would not buy a carb unless it is a 'double pumper.'
4) They want the cheapest looking chrome anything & everything that they can afford to buy even if their kids starve.

It is truly refreshing to hear you guys get it right over and over again. Yall just blow me away with the depth of knowledge here. Mike and number dummy have kind of gotten the rest of us up on our game, and thats a great thing.