Haven't posted in a while...but I need some advice ..My 84 F-150 has the 351 W/Factory 4 bbl. Over the years the carb has been switched to a Holley 600. Truck is Automatic..A/C..Everything hooked up and operating as original......even down to the dashpot and kickdown...108K miles. It is hard to start..sometimes..I use it maybe once a week..Runs at the temp. it is supposed to... 160 degree thermostat..When it warms up..it's better..but still stumbles and just runs bad in gereral...at times. Carb had a pro rebuild...and I have had many Holleys over the years..none memorable..except one on another built 351 W...A friend with a Tiger switched to an Autolite 4100..or 4300 ??..Has anyone used the Edelbrock ?..The Holley has to go...EXPERTS..please weigh in....thanks..JV

 

I've had pretty good luck with the edelbrocks.

 

Never had one..But I've had NO luck with this Holley..Had a Holley on my Cobra Replica..289HiPo..and one on a a built Windsor..NO problems..Maybe its just the carb...but it HAS to go !!..C'mon guys ..HELP !!!

 

I would think a 351 would not need more then a 500-550 cfm carb. What was the factory carb a Holley 4180? I've had great luck with pony carbs rebuilds and they take all the flaws out of whatever carb you have them build. I just find that often times the best carb is the factory one since that is what it was designed for. And there are places like pony that takes the flaws out, like bogging and fuel leaks and the like.

Me personally my favorite carbs of all time are the Autolite 4100s, especially the 66-67 Big block ones from the full size cars and thunderbirds. They are a square bore carb, but those have 1.08 throttle bore instead of the 1.12 and act like a spread bore and I get great economy with them and they never need adjustment, I've ran a couple for about 10 years and have never touched them once since the initial adjustment.

Maybe it don't work right because the choke is not adjusted properly? Or maybe you thermostat is too low? I usually run a 180 degree or 185.

 

I believe your only choice is going to be a Holley or Edelbrock. Any other OEM carb is going to be used and need a rebuild, and then you don't know what it's jetted for, and good luck finding tuning parts for the OEM styles.

I like the Holleys because that's what I am familiar with. Like you said, they are a good carb, just sometimes you get a carb(any brand) that doesn't seem to run right.

I bet I know what's wrong with the Holley. The main body is warped where the metering block mounts, and it needs to be machined flat. Very simple thing to do if you have a milling machine. There is a way to check it also, but I am getting hints that you don't mess with carbs yourself.

 

You can flatten the metering block surfaces on a surface plate with emery cloth as well.

-Enjoy
fh : )_~

 

First off, a 160 degree thermostat is not good. You are not doing your truck any favors by running it that low. What is happening is your truck will never get hot enough to burn off moisture that accumulates inside the engine, and that causes SLUDGE to build up. The stock thermostat is 190 degrees. I wouldn't run any less than a 180 degree. I would change the thermostat first before doing anything else.

Second, keep in mind that you are not running electronic fuel injection. Meaning you can't just turn the key and expect a carbureted vehicle to start immediately if it has not run in over a week.

Are you running a choke, and is it functioning properly? A carburetor absolutely needs a functioning choke in order to start smoothly and quickly.

What is your starting procedure when your truck hasn't been driven on over a week? The carburetor's fuel bowls tend to dry out in about a week or so and that changes your normal starting procedure.

If you are going to replace the carburetor, I would replace the aftermarket Holley you have now for the original Motorcraft 4180 (made by Holley for Ford) your truck originally came with and go from there. The Motorcraft 4180 is supposed to be really good carburetor, and it will have all the ports you need for the engine accessories and emissions you have. I know that they were used on the Mustangs in 1983 - 1985, so you may want to check with the guys over at Welcome to FourEyedPride.com. Most of the guys there are really knowledgeable on the 4180.

As far as the best carburetor goes, you are going to get a lot of different answers, but I am going to agree with fepowerguy8 and say that the Ford/Autolite 4100 is probably the best, most reliable non-emissions four barrel carburetor ever built for day-to-day street use.

I switched from a Holley Truck Avenger (470cfm) to an Autolite 4100 (480 cfm) myself and it was a dramatic improvement. This is a very simple "tune it and forget it" Ford- engineered carburetor that actually uses the same jets and power valve as a Holley. The "hot air" choke works much better than the Holley electric choke, which helps it run much smoother when the engine is warming up. You can't get any closer to EFI than a properly tuned Ford/Motorcraft 2100/2150 (2V) or Ford/Autolite 4100 (4V). These stock carburetors utilize annular boosters, which atomizes fuel just as well as EFI. The Motorcraft 4180 carburetor your truck originally came with also used annular boosters on the primaries. This translates into snappier throttle response AND better fuel mileage!

If you are running a basically stock motor and need or want to keep your emissions components, I would go with the Motorcraft 4180. If you are like me, and are starting from scratch and don't have to worry about emissions, then the Autolite 4100 would be my choice.

 

I made a few revisions to my earlier post and accidentally posted it again. Sorry!

 

That's what I'm talkin' about !!...I replaced the 180 with the 160..Still runs between "R" and "M"..Electric choke..Works..I usually have to pump it 3-4 times after it has set for a week. I drove it yesterday..Got in it today..no pumping..Started right up..Got to operating temp..but always stumbles when I accelerate. The truck has everything original..and working.... except this Holley..and a Flowmaster... Occasionally it acts like it wants to die under acceleration at 50-60 MPH...Sounds like the Autolite is the way to go.....I don't think the truck was driven ..only started all last winter. Put some Sta-Bil in it last fall...I'm just ready to dump the Holley..Thanks..JV

 

Stumbles, where?

Just off idle?
The accelerator pump could have a sticking check ball, the wrong cam, improperly adjusted clearance...

Closer to 2k?
Vacuum secondaries? (I hope)
If it is from, or for, a car it's likely the spring is way too light.
Try a plain, or even a black, spring and see where that gets you for starters.

Maybe you ought to go back to the stock 4180.
I really liked mine until I just wore it out. (now using an 0-80475S)
It was engineered and calibrated for your truck.
There's a good article archived on FLEMWORLD under - '85 How To's-
outlining the basic differences of a 4180 v/s the 4160 and how to make performance modifications.

I have to agree with Lariat, you're running your engine way too cold.
Unless you have a REAL temp gauge you have no idea what "normal" is.
Try cleaning the terminal or even changing the sender before you swap in a colder thermostat and do serious damage to your engine.

Just my 2c

 

DOnt know if it helps ,but I have a used Edelbrock 1406 650 sitting on my shelf with an triangular edelbrock air cleaner w/ a K&N filter for $175.00 shipped. Has electric choke. The chrome air cleaner has some surface rust but could be cleaned up or repainted. PM if your interested.

 

I like the 4180 Holley or a 4100 Ford carb for these trucks because of the annular boosters they have. They give a much stronger vacuum signal and offer much better
drivability because of that. Standard Holleys have the smaller dog leg boosters which
offer better total flow but scarifice some low speed drivability. A 4180 can be made to
run very well with a careful rebuild with a quaility kit and a few tweeks such as a single
stage power valve and properly adjusted accelerator pump.

 

Looks like the FORUM has spoken. 4180 it will be..Anyone have a decent one..that they would part with ?...J

 

You have another problem somewhere. I am running a 180 and my gauge is at the "O" and "R" at normal operating temperature. Your gauge could be wrong, your sending unit could be wrong, your radiator may be clogged up, or you may want to check your fan clutch.

All of this sounds completely normal for a carbureted vehicle. Pumping the gas 3-4 times to start it after it has been sitting for a week is necessary because the fuel bowls begin to dry out. As long as you drive it every few days, one pump should start the engine, and if the engine is still hot, no pump is necessary to start your engine.

What you are describing is the same thing I experienced with my own Holley Truck Avenger I was running before I replaced it with the Autolite. For some reason, I had this "stumble" I never could seem to completely eliminate. I tuned it several times, and even had someone else who grew up with carburetors tune it for me, but that stumble was always there. When I replaced it with the Ford carburetor, the stumble disappeared, I got more power, better throttle response, AND better fuel mileage.

 

I took a 180 out a couple weeks ago ..and put the 160 in..Gauge reads the same..If it idles a bit..temp starts to climb..I drove it 20 miles last month..Got out at a friends..was 20 feet away when the top hose BLEW APART !!. At times the gauge runs a bit hotter..As far as I know it's the original radiator..Haven't checked fan clutch. Factory shroud is in place..I've just had it with this carb...j