So I thought it was a 600cfm "emissions" 4160. After doing some research, I found out the thing came off my mom's old '84 Mustang GT and that it was a 4180. It has annular primary boosters, the standard 30cc accelerator pump, a bunch of interesting vacuum ports, and those stupid fuel bowls with the tubular vents in them.
I found an article on how to hop up this carb (download the zip file) http://www.ddilts.net/mustangs/holley_4180/index.html Lots of good info, but I seriously wouldn't run it with those fuel bowls! I did change a few things that the article didn't get into though. It has standard side-feed fuel bowls from an 1850-3, a bigger accelerator pump nozzle, and bigger primary jets.
I put it on my 460 yesterday - bolted right onto the stock intake manifold without even needing a spacer. Once I got some fuel into the bowls, it fired right up. The thing wouldn't idle though because the 80's Mustangs had that electric idle solenoid (that I chucked) so I had to devise my own idle-stop bracket. It only took me an hour to get it tuned up and running good and I'll tell ya it runs WAY better than the Motorcraft spread-bore! Throttle response is crazy... I keep accidentally chirping my tires at stop-signs! And everyone told me it wouldn't work because the carb was intended for use in a 302 (which makes it all the more better since it works! )
I'm writing up a spec sheet so I can share the good combination of parts I used and hopefully I'll have some pics up tomorrow.
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People work from sun to sun but a gearhead's work is never done. -An old mechanic's adage
Last edited by crazyeddie; 09-18-2009 at 05:39 PM.
Reason: fpewwing waf ronge
I figured 600cfm was a little skimpy because my uncle is running a basically stock 460 in his jet-boat with a 700cfm Holley and it runs awesome - but then again it's a boat and he runs it around 3-grand+ most of the time.
How many cfm's does the Motorcraft 4bbl flow? Wasn't it around 650 or so? I wonder why Ford quit using Holleys for a while and went with the spread-bores. I'm impressed with how good it runs with the Holley!
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People work from sun to sun but a gearhead's work is never done. -An old mechanic's adage
Glad you found the article...sure save me alot of time trying to explain why the 4180 isn't just a "smog type" carburetor. I actually prefer the performance characteristics of the 4180 over that of a 600 cfm 4160 on a stock 460 as you may have already found out. Most 4180 carbs have four idle mixture screw hidden behind steel tamper-proof plugs. I did seen a 4180 with just the two primary idle mixture screws and no secondary idle mixture screws. It's a must to remove those tamper-proof plugs. I drilled mine out but it's time consuming and wear out a lot of drill bits. The tubular vents in the fuel bowls can be pulled out and replace with a steel expansion plug (freeze plug). I don't understand why you couldn't get it to idle without the electric idle solenoid. Every 4180 I seen had two idle speed screws...one for the primary throttle shaft and one for the secondary throttle shaft. Holley quit making the 4180 after 1985 and thus didn't make any replacement parts unique to the 4180 such as metering blocks. Problem is when working with parts that are 25 years old or older and made out of aluminum there is no telling how much corrosion there is in the internal passages of the metering block. Everything else on the carb (carb body, base plate, rear metering plate) are fairly easy to get clean...but the front metering block can sometimes be impossible to clean. If you are using the two-stage power valve I would be hesitant about changing jet sizes. I like to think of power valves as the mysterious "third jet" in a carburetor.
Parts for the 4180 are indeed quite hard to come by. I lucked out seeing as how the carb was stored bone dry in an attic prior to me using it. I'm surprised also that there isn't an idle adjustment screw. There's a set screw adjustment for the opening of the secondaries, but nothing for the primaries... not even a drilled and tapped hole for a screw to go (I can change that any time I want to though... have a Bridgeport mill at my disposal ) Since the carb was off a manual trans mustang though, it had the dashpot and electric idle solenoid so I guess Holley figured a screw wasn't necessary.
I've found though that there are a ton of standard Holley parts that are exchangeable with the 4180's. I traded the bowls with the vents for standard side-hung float bowls from an 1850-list carb, and back when I thought the carb was just a goofy 4160, I bought a Holley 4160 TricKit. I had to punch a few holes in some gaskets and remove some extra material, but other than that, everything worked. I set aside the old two-stage power valve and used the high-flow rectangle port power valve they gave me in the kit (opens @ 6.5).
I saw another article that shows you what to do to make a 4180 similar to a 4150 with dual metering blocks - takes some drilling and machining but it's been done with good results.
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People work from sun to sun but a gearhead's work is never done. -An old mechanic's adage
That would be a bummer not having an idle speed adjustment screw for the primary throttle shaft. When I rebuild a 4180 carburetor I like to have everything set up before I bolt it to the intake manifold...that includes setting the float level (don't waste your time setting brass floats until you have gas in the carb), the high speed idle screw (ensuring it clears the last step on the cam when taken off of high speed), setting all four idle mixture screws to 1 1/4 turns out, setting the idle stop set screw on the secondary throttle shaft for 1/2 turn in from closed throttle, and setting the primary idle speed screw for a slight (I'm guessing about .015") exposure of the the transfer slot. And of course checking the clearance between the accelarator pump actuating-lever screw and the diaphragm lever at WOT with the diaphragm fully depressed. I prefer .020" clearance.
What is all this "transfer slot" business? I didn't even fool with the secondary adjustment. I turned out the set screw just until the plates closed all the way then turned the screw in a half-turn.
As for there not being an idle adjustment screw, I rigged my own idle stop with a dashpot bracket until I get to drill and tap the base to accept the screw.
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People work from sun to sun but a gearhead's work is never done. -An old mechanic's adage
I was just explaining how "I" go about setting up a 4180 carburetor before bolting it to the intake manifold. It was intented for other viewers who may be reading this thread and who may be looking for tips on setting up their 4180 after a rebuilt. Setting the curb idle speed screw for a slight exposure of the transfer slot before bolting the carb to the the intake manifold isn't even necessary and was intented for those who may be interested in what would be "ideal" ....however, what is ideal never works out in the real world when the carb gets installed, engine running and warmed up, final adjustments made, and the fact that most of you are running ported vacuum to the vacuum advance on the distributor.... so it may be best to forget about the "transfer slot" business.
I was just explaining how "I" go about setting up a 4180 carburetor before bolting it to the intake manifold. It was intented for other viewers who may be reading this thread and who may be looking for tips on setting up their 4180 after a rebuilt. Setting the curb idle speed screw for a slight exposure of the transfer slot before bolting the carb to the the intake manifold isn't even necessary and was intented for those who may be interested in what would be "ideal" ....however, what is ideal never works out in the real world when the carb gets installed, engine running and warmed up, final adjustments made, and the fact that most of you are running ported vacuum to the vacuum advance on the distributor.... so it may be best to forget about the "transfer slot" business.
Oh so the transfer slot is the pickup for the timed vacuum port for the timing advance? That's all I wanted to know - just wondered what you meant by "exposing the transfer slot".
Thanks for the tips BTW. I've found that there's not a whole lot of people that want to take the time to srew around with this series carb.
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People work from sun to sun but a gearhead's work is never done. -An old mechanic's adage
I was referring to the idle fuel mixture transfer slot in the throttle bore. It's the vertical slot just above the idle discharge hole. The transfer slot is what allows more fuel into the throttle bore when the throttle plate is moved just above idling speed (as when you press on the gas pedal to give it a little more gas). As the throttle plate moves up, more of the transfer slot is exposed to below the throttle plate where engine vacuum sucks in more fuel from the exposed slot. The .015"-.020" exposure of the tranfer slot below the throttle plate would be about right (within a half of a turn of the final adjustment of the curb idle speed screw) on vehicles that run full manifold vacuum to the vacuum advance on the distributor. Ported vacuum does not give spark advance at idle and thus will require more turns of the curb idle speed screw to achieve the correct idle speed.
The mixture screws are in the baseplate and the plugs have to be drilled out to access them. There are two in front and two in the rear.
These carbs do run really well when they are right. I have one in the garage off of my Ex girlfriends 85 GT Mustang. It is partially disassembled and missing a few pieces these days. The front boosters give good throttle response and low end power.
Just found your posts on the 4180 Holley. I have one from my 1986 Bronco that I am trying to rebuild. I called Holley with the list number on the Carb, and they told me to get kit 37-485. It came in the mail, and has all the wrong gaskets. I found a kit on ebay motors that says it is for 4180c carbs. Would you by chance know the correct Holley trick kit for these carbs??? Help is much appreciated!!
The Holley 37-485 kit according to Holley website is for the Holley 4150 carburetor. The Holley website doesn't list a rebuilt kit for their remanufactured 4180 carburetors. I got my rebuilt kit from Autozone a few years ago. Autozone show a GP-Sorensen (part number 96-483B) kit for $26.99. They no longer stock them in the store, but they can order one from the warehouse.
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Franken-Holley (a 4180) comes to life!
it runs WAY better than the Motorcraft spread-bore! Throttle response is crazy... I keep accidentally chirping my tires at stop-signs! And everyone told me it wouldn't work because the carb was intended for use in a 302 (which makes it all the more better since it works! 
)
Engine compartment needs help. Wires running everywhere, rusty stuff, and my hillbilly double stacked, mismatched air cleaner elements.
) Since the carb was off a manual trans mustang though, it had the dashpot and electric idle solenoid so I guess Holley figured a screw wasn't necessary.
