That was cool. I remember well when 100,000 miles was a big deal and people were happy their car made it that far. Many cars did not. Fuel injection eliminated cylinder wash down for the most part, helping more modern engines last much longer. This, plus better oils, piston ring tension, etc. made cylinder wear almost a thing of the past. Carburetor and choke problems were not good for engine life.

@21stcenturyfossil7

2 жыл бұрын

Unleaded gas was probably the biggest factor. Carburated cars easily went past 100,000 on unleaded. Leaded gas contained ethylene dichloride and ethylene dibromide which broke down to strong acids in the heat of combustion in order to control lead and lead oxide buildup. Needless to say, these acids weren't selective in what they corroded.

@ldnwholesale8552

2 жыл бұрын

Cylnder wash? Happens equally with ULP. Because of ULP modern engines are forced to use far better pistons, rings, valves etc. Better oil too ofcourse, formulated for ULP.

@donreinke5863

2 жыл бұрын

The change to higher nickel block castings was the primary reason newer engines would last longer. Post 1986 Chevrolet engines would often show a hone pattern at nearly 200,000 miles while 86 and older small block Chevys had a noticeable ridge and occasional scoring by the time they reached 100k.

@thomaslemay8817

2 жыл бұрын

I noticed no mention the fact that the PCV system keeps the fuel vapor out of your oil gratley improving lubrication quality. You see all the systems that reduced fuel emissions helped make engines last longer by getting a stranglehold on wasted fuel both in the oil and in the exhaust . That is the reason fuel injection was adapted to get better control of fuel. The improvement in engine life was an accident ! Car manufacturers want to sell cars, if the cars last longer they sell less cars.

@donreinke5863

2 жыл бұрын

@@thomaslemay8817PCV systems were first used in 1963. Engine longevity was virtually no different in mid to late 1960s cars than 1962 and earlier engines that utilized a road draft tube or pipe for crankcase ventilation.

You hit the nail on the head. I worked at a dealership during the later years of this carb, and they were the WORST. There was a service bulletin concerning some of the design faults, but ultimately, this carb was just poorly designed crap. I especially despised the secondary split shaft. Hot soak flooding was horrendous. Just as you said, the Edelbrock carb was a VAST improvement - I've swapped many. I can still hear the moans and groans from owners and mechanics alike concerning the infamous variable venturi carb (feedback and non -feedback) but, unlike the 4300 /4350 carb, it can be fixed, and I specialized in doing just that - for decades. When I saw this video listed, it brought back the unpleasant memories, and a lot of grief that I had with the 4300 /4350 - and I just had to see it! You are right on. Great job!

@RareClassicCars

2 жыл бұрын

Thank you!

@gabrielleandro6246

8 күн бұрын

Is this bulletin publicly available? And what was the "fix" you had for it?

I was a tow truck driver during the period these carbs were on everything - can't tell you the number of road calls I answered for a no-start. The engine would crank, but no start, usually on a warm day in a parking lot after a good heat soak. The routine was simply take the lid off the air cleaner, shove a screwdriver down the carb to block open the choke, then get in an floor the gas and crank until it cleared out and started. Of course, the owner usually had made things worse by pumping the gas like a pump organ to thoroughy flood it.

@akallio-lj7dm

2 жыл бұрын

Didn't they have a "choke unloader" to open the choke plate a quarter inch or so if you held it to the floor?

@johnz8210

2 жыл бұрын

@@akallio-lj7dm Yes, but every time you pushed the pedal to the floor you also made the accelerator pump squirt some more fuel in the already flooded engine. You were better off doing what the tow ruck driver said in the other reply.

@daveallen8824

2 жыл бұрын

Theoretically...

@LakeNipissing

2 жыл бұрын

"Of course, the owner usually had made things worse by pumping the gas like a pump organ to thoroughly flood it." .... because that is what everyone did in the movies!

@howebrad4601

2 жыл бұрын

@@LakeNipissing I also know people that do that. Typically they develop that habit because they're so used to driving worn out carbs where the accelerator pump barely works so they "had to" pump like crazy. Good points here in the comments

My father bought his 68 Cougar in April 1968 in San Diego. It is a 302-4V with the 4300. He always had trouble starting it in the morning so I was the one to start the car. The car became mine in December 1969 and I had no real problems. In 74 it got a Holley 600 cfm 4bbl. for the next 20 years. The car currently runs a Autolite 4100 rebuilt by Pony Carbs. The 4300 is on the shelf. Ironically my 67 Parklane has a 4300 on it now. However, it was rebuilt by Jon at Pony Carb some years before he passed away. How he modified it was his secret but the carb runs like the car has fuel injection. It runs beautifully thanks to Jon. He even got on the phone with me to tell me how to adjust the idle speed via the large screw in the back.

Does this mean that a Quadrajet video is on the way? The QJ has been maligned for so many years that it would be nice to see a knowledgable defense of it. When I was a teen, I was one of the QJ detractors. But now that the Internet has provided the background info that wasn't easily available back in the day - and I've been able to put that info to use on a '67 QJ in an Eldorado - it seems that a properly operating QJ is almost indistinguishable from fuel injection: The QJ works very well.

@joshuagibson2520

2 жыл бұрын

Properly setup and tuned QJ is the bees knees. As you eluded, most folks just didn't understand or know how to work on them.

@purpurahaze9179

2 жыл бұрын

@@joshuagibson2520 one of the greatest sounds driving a older vehicle the sound of a Quadrajet opening up at full throttle

@joshuagibson2520

2 жыл бұрын

@@purpurahaze9179 amen brother my 79Z has a QJ and it's glorious when you open all 4 up! May only be 180HP, but a damn lot of fun!

@codyluka8355

2 жыл бұрын

I never had a problem with QJet carbs. I thought...and still think they are great carbs. There are issues that can pop up such as leaky float bowl plugs but those can be easily corrected. If the throttle shafts have no play and it's in rebuildable condition, you should have no trouble.

@garypeterson9083

2 жыл бұрын

I had QJ 's on all my chevs back in the day. I beat many holley equipped cars on the street too. It took a little tweak here and there but I loved them. That all ended when they added an idle mixture solenoid and other emissions crap to them.

I bought a pretty well used 69 Cougar with the 351 4V in 1977. Shortly after I bought it, I replaced the original carb with a rebuilt from Ford. The original leaked around the accelerator pump and was pretty well spent. No major problems with the rebuilt..........until one day when my wife got home from work and told me that the car smelled funny. Nothing looked amiss, so I started the engine, when I did a flood of raw gas poured out of the bowl on top of the hot manifold. She had driven about 15 miles home with this happening! The gas dried up quickly, when the engine cooled I pulled the carb to see what was going on. A little brass plug in the bottom of the bowl that should have been staked in better had fallen out, it was laying right there in one of the crevices on the intake manifold. I put it back and staked it in, there were no more troubles with that for the remaining time I owned that car. It's scary to think what could have happened, fortunately it didn't.

@fastinradfordable

Жыл бұрын

Gasoline doesn’t really catch on fire on the exhaust. If you listened to ‘car talk’ You would know this

As a teen, I had a 1967 Cougar with this carb. I found this video very funny to watch. I thought my 4 BBL 289 was the fastest thing around, especially after I rebuilt the engine. As a naive kid with limited finances replacing the carb that as far as I was concerned was awesome was never in the cards. Naivety, I miss you so. Sort of.

@errorsofmodernism9715

2 жыл бұрын

naïveté

@CORVAIRWILD

2 жыл бұрын

@@errorsofmodernism9715 nativity lol

@mikehunntt5338

2 жыл бұрын

Didn't have nuttn on my 289 67 mustang baw!

@willallen7757

2 жыл бұрын

yeah bummer, I bet a Holley 500 cfm 2 barrel would have made you think you were in GT40 times.

The Edelbrock AFB is one of the easiest 4bbl carbs to tune and adjust (along with the original Carter AFB). But my favorite carbs are the GM quadrajets before they computerized them in the late 1970s. Probably the most fuel efficient 4bbl was the old Rochester 4GC or 4-jet.

And here I was expecting a variable ventri segment lol. Agreed, the 4300 was also not a good carb in stock form. Imagine, dual needle and seat on a 440 cfm carb. No imagination in my head gets me to understand.thanks again Adam

@jeromebreeding3302

2 жыл бұрын

True the 4300 carb was abominable, whereas the 4100 was a reliable performer. Easy access to accelerator pump, and jet changes easily done by removing the top. They came in 480 or 600 cfm. The difference being venture size.

@brianhdueck3372

2 жыл бұрын

@@jeromebreeding3302 yes I put a rebuilt 4100 onto a 351M with edlebrock intake. It was dead reliable with zero issues right out of the box. That fuel setup with Comp Cams 268H high energy was a really amazing wake up for that engine. Ran smooth and pulled really well

@jeromebreeding3302

2 жыл бұрын

@@brianhdueck3372 The 4100 is just as good as a single feed Holley, as long as your came is not to lumpy. Mods can overcome this, but someone who knows the carb well should be consulted.

@ronniecox109

2 жыл бұрын

I worked as a transmission tech at a Ford dealer when the variable venturi came out. Man they had so many driveability issues with them. One tech could make em work . He flagged 50 60 hrs. Every week.

@briansearles4473

2 жыл бұрын

I drove an 1987 Crown Vic Wagon with a 351W variable venturi carb until around 2005. My biggest complaint was the cold start circuit. The engine would be screaming at a super high idle long after warm-up. Only way to get it down to a normal idle was to put it in drive and floor it at the first safe opportunity to engage the kick down. I took the car to many different Ford dealers, the problem was never solved. Then one morning the cold start circuit failed and I never fixed it. I would "juggle" the gas pedal for a half minute or so until it would idle without stalling. Keeping the car in a warm garage during the winter was a big help. Whenever I discussed replacing the VV carb with something else I was always told nothing would give as good gas mileage as the variable venturi?

And all this time I didn’t think there was a bigger car dork than myself. 😁

I had a 1963 Ford Fairlane with 221 V8 and large 2 barrel carburetor. It ran and started good.

Agree 100 percent!! slap a 600 Holley on it and prob. solved! Love your channel man! Chris from East Tn.

@joshuagibson2520

2 жыл бұрын

Hey neighbor. Morgan Co here.

HI Adam, great video. I agree about the 4300 carb being such a challenge. I own an all original 1974 F350 Super Camper Special pickup with XLT trim , 460, C6 and only 43K miles. Immaculate. Sits in the garage and only goes to occasional car show. I think It had the 4300 carb and it was always something wrong. I rebuilt it a couple of times, had professionals rebuild it and it just didn't matter. Flooded, vapor lock, etc and it really took away the fun of driving it. Drove me nuts so I eventually replaced it with a Demon carb about 11 years ago. I still have the original Ford carb in a box. Thanks for sharing!

@RareClassicCars

2 жыл бұрын

Wow. What an awesome truck!

The square bore Autolite 4100 was one of If not the best OEM 4bbl of its time. Holley made a version of this, and it’s still available as Summit Racing carb in 600 or 750 CFM with vacuum or mechanical secondaries. Very light, no metering plates, one piece body with a removable top plate. Annular boosters make for nice throttle response.

Adam, you make the most beautiful video backgrounds.

I fixed a too lean condition on mine by cutting off the tapered down section of the fuel draw tubes you show in 5.49 this was back in the day when i fixed everything , I had a collection of carb kits and one time to fix a non replaceable float needle seat on my 200 cu in ford mustang i drilled out the seat and epoxied in one from a carter or some other carb, worked great and stayed put fine .

I have an original AMC 360 P code intake WITH it's AMC tagged 4350. It's there for OE documentation purposes only...only the ThermoQuad had me cursing more. I recall that TOMCO rebuilds would always leak around the upper third, as the outer perimeter screws would be overtorqued, warping the unit.

Had this carburetor on my 1969 and 71 Mark IIIs. They both had issues. Mostly leaks at the front of the carb where the air horn screws down the main body. I've had to double up the gaskets to stop the leak. Honorable mention was the crappy Variable Venturi 2bbl, junk...

@tommypistols8104

2 жыл бұрын

Them Variable Venturi carbs were very problematic and often replaced with a Carter or Holley carburetor.

Had a 75 cougar with a 460, that would always stick wide open throttle. I had to shut the engine off to get it to close. A friend borrowed a late 60s pickup from his buddy during lunch break in high school, mashed the gas pedal around a corner, and put the truck up the lawn, up the steps,and through the front of the house. Police refused to believe that the accelerator was stuck to the floor.

@moonbeamskies3346

2 жыл бұрын

Good grief! That sounds like a deadly problem

I am always amused by this content. As an early adopter of efi, I don't miss this stuff. The only carb around here is on me lawnmower. I do recollect me mighty 289 Mustang I had as a teen....with the equally mighty 2100 2 bbl. That carb had about 8 parts in it, never busted and had, I think near 400 cfm in v8.... applications.

It seems that all cars had "quirks" during the change to unleaded gas and early smog equipment, part of the learning curve. Thanks for posting......

An excellent overview, Adam --- I learned a lot! Thank you.

Hey Adam, thanks for sharing another informative tranquil setting video!!! 👍👍

Please talk about the Variable Venturi carb. Great idea, but not on the long term. The car ran OK until the sliding needles would wear the jets and the car ran too rich. SU carbs were VV and they were fine.

@LakeNipissing

2 жыл бұрын

Didn't Honda also use variable venturi carburetors in the 1980s and also have trouble with them?

Another awesome discussion, Adam!

The weird/oddball Idle speed adjustment was actually Good Engineering. A lot of poor Low Speed Drivability Issues(especially on Emission Carbs) are the result of poor Throttle Plate position in regards to the Off-Idle Transfer Port/Slot, which was affected by using the Throttle Shaft as the Control for Idle Speed. Moving the Adjustment to an Air Bleed, or even to the Secondary Throttle Plate, would maintain the proper Relationship between the Plates and the Off-Idle Transfer Slot. The Spring loaded Accelerator Pump is really no Different than that of a Q-Jet, If that spring wasn't there, the Linkage could get bent, as Liquids are not compressible, and the Pump Circuit is restricted. Holley also has a Spring in its Accelerator Pump Linkage, for the same reason Here is a link to a Ford Service Manual about the 4300. www.forelpublishing.com/demo/vamustang/Demo10177.pdf It explains the unique Float Valves. The Auxiliary Valve here is actually held closed by the pressure in the Fuel Line. Most Q-jets were 750CFM, the 800 is a lot Rarer than you imply. Even on most Big Blocks the 750 CFM was oversized. A BB 7.5 liter engine with 75-80% VE, spinning 5000 Rpm, only used about 540 CFM

@pjimmbojimmbo1990

2 жыл бұрын

@Ziplokk I did that on my old man's 74 Buick with the 455, but that was back in 1978

@pjimmbojimmbo1990

2 жыл бұрын

@Ziplokk My dad and I both had 1976 Olds 88s but the flipped lid never sounded as good as it did on the 74 Buick. Different Camshaft Timing/Grind might have been the reason

Always enjoy your videos, both from a mechanical as well as historical perspective.

As always, your videos never fail to impress

Wow. Great video. Been watching for a while . Just subscribed. Thanks

Great content, Adam, well done. Thanks.

Another great episode Adam !!

The Autolite 4100's were so much better. They even had annular discharge boosters on the primary and secondary barrels. Holley actually copied the carb later on that is discontinued now but Summit Racing sells them now as their M2008 series.

@loumontcalm3500

2 жыл бұрын

The "flattop" 4100's are great- a friend has a '60 Ambassador which came originally with a Holley 550. Couldn't get it to run right. I've had Rambler's with Holleys. Can't stand them! Who designs fuel bowls sideways with crossover tubes? I suggested he find a 4100 to replace the Holley. He did; car runs great. It's not original... but it works.

I too have been around the Autolite 2 barrel It reminded me so much of a Holley . They worked great, and quick to rebuild as you said

To give everybody an idea of just how TINY the '67 versions of this carb were, the 2SE Varajets used in the early 2.8L Chevy V6s and in some Iron Duke I-4s had a CFM rating of 375 (28mm primary) or 397 (30mm Primary). And that Motorcraft carb was put on V8s!!!

Cant say Ive had any issues with mine. I drove my 72 for 50k miles, on the stock carb and then a Pony carb rebuild. The old one had a warped base plate. My 73 had some rando marine carb on it, so I but another 4300 from a 72, with the egr baseplate instead of the 4350 iirc. Neither have any issues bogging, power issues. Im not a carb expert on all carbs, but maybe the fact that I know this carb well, makes me not think of it as a bad carb. It just needs to be set right, and that is where I came across A LOT of cars with really poorly set up carbs, and other terrible settiings, dwell, timing, etc. I remember one with performance high energy plugs and wires and it was running terrible. Setting things back to factory made it purr. I think most people think of the Continentals as potential muscle cars. Sure, they got torque and will move, but these aint Cobras.

I had a 4350 that the secondaries stuck open frequently. I took one the return spring on one side and wound it one more time and that fixed it.

Great info. I've always wondered why a lot of ford engines, and I own several, never seemed peppy or wanted to run decent. Now I know why!! Excellent video

Wow, very good breakdown!! I heard they were not the favorite but this just showed why...

Excellent video, once again you are spot on. Another problem on the later units was the electric heated choke thermostat which was prone to failure causing the choke to not open fully and stay on fast idle. I like you videos because you are impartial and just talk about all facets…good and bad.keep them coming.

@JohnSmith-wj2wd

9 ай бұрын

This may explain why my choke valve is missing. I assumed it had to do with an LPG conversion that the previous owner put in, yet I couldn't find any info about it. Now I'm rebuilding the 4350, and the thermostat is indeed toast. What I assume has happened, is that the choke got stuck, and rather than adjusting it all the way open, they simply got rid of it altogether.

lucky you, were getting the snow that just went over you a few days ago here in NY. Fun stuff.

Autolite 4100 good too. Had one on a '64 390. Country Squire wagon bought in '75 for $150. Great car!

Thanks for the tips.

Maybe I was just fortunate. But when these carburetors were popular, we had good luck with them. They seemed no more problematic than the Quadrajet. The accelerator pump was somewhat problematic. But other than that, we didn’t see an abnormal amount of problems

We had them on our local GT Falcons and some T code Fairlanes from 67. Big performance upgrade from the 2V, but they (4300) in my opinion, needed a wise head to tune correctly.

Musta been replaced on my '71 Lincoln, assuming it had one. Killer car.

I have had 23 Fords from 1950 to 1966 model years. I had ONE 1967 Mustang with a 289 and one 1968 Torino with a 302. I do not recall, but they must have had 2-bbl carbs. I do not think I have ever owned a 1967 or newer Ford with the 4bbl carb. So this is all news to me. My 1956 and 1957 T-Birds came stock with Holly carbs. Not sure when the FoMoCo, Motorcraft or Autolite carbs became standard equipment. But certainly my early to mid 1960s Fords had them.

I agree 💯 having this carb on my 71 Mark III. I cannot WAIT to finish the engine and trans rebuild and swap in a new Edelbrock 750. I had literally every issue you described!

Driving cars with these will make you really good at feathering the pedal . That's a pretty good assessment of the edelbrocks imho.

I love the efi tech but I just love hearing all four barrels open at wide open throttle. I have a 79 buick with a 403 4v....it uses a lot of gas!

I don't know much about that carb you were taking about, but I can vouch for the 2100 and the 4100 carbs. I used 2 - 2100s on my 66 Mustang for years. I ran 51 jets in the summer and 55 jets in the winter, like below zero. I loved that car.

The predecessor 4bbl Autolite/Motorcraft 4100 was so dependable and easy to tune, it's a shame the successor was such a mess.

and then there are the god-awful Ford automatic chokes. Through the mid 70's and early 80's my Dad had 73 Custom 500(351C), 74 LTD(400), 75 Montego Wagon(400), 75 TBird(460), and my sister had a 75 MkIV(460). I ended up putting manual chokes on all of them

@postmodernrecycler

2 жыл бұрын

Oh my god those dreadful auto chokes on all my '70s Lincolns. Full throttle crap!!

I didn't know that Mark Ruffalo knew so much about carburetors?! Thanks Hulk!!!🤣🤣🤣🤣

I don’t remember the model carburetor I had on my ‘83 Ford Ranger with a 2.8 L engine, but the passages at the base would get clogged and I had to remove it from time to time to clean it.

Thanks for the info, Tips, I been having trouble OEM 73 T Bird 429 4300 carb rebuilt within a few weeks now running like crap. Now I know why. Was trying to keep it all OEM but not if its going to be a big pain in the @ss, will try the block out tip

Yeah.....lol! The 4300/4350 were just headaches from the GO. I have convinced many Motorhead friends to just swap it out for a Holley 1850/600cfm, or an Edelbrock AFB 600. I told one friend to. ".. quit chasing your tail like a puppy and put a carb that works with minimal micky mousing! " And that Ford VVcarb... yeah. Thank goodness Holley made a replacement 2300 2bbl with the electronic parts to the simple computer "Everything's AOK!". Lol!! The 4300/4350 was a poorly engineered answer to a non-existent and never encountered problem. I have a brand new Motorcraft 4300, still sealed in the box way up on the shelf in the shop a hot rod buddy GAVE me, free, years ago. He had good intentions to help me with a hot rod build. I still bought a new Holley Universal......... Lol!

@Chitwn81

Жыл бұрын

Do you want to sell it? I need a carb for my 72 Mark IV as my carb is leaking like crazy out the top and screws are stripped

@johnwhitley2898

Жыл бұрын

@@Chitwn81 OMG lolol 😂😂.... I would if I could remember Where it is now. I've moved to a new house and shop garage since then. Well, it was actually a "forced" move... Not mad, just a little bit put out. Sorry 😐!

I do strongly agree that the Autolite 2100s and 4100s are the most simple carburetors ever made and are very easy to work on. In the whole time we had a Ford with the two barrel 2100 on it (25 years at least), I saw my Daddy replace the diaphragm for the accelerator pump once. Never took it off the intake and did anything with it like that. Just changed the accelerator pump diaphragm.

70 mustang carbs used a disc check valve that rarely works correctly causing fuel to shoot out of top of carb instead of down the venturis, 4350 went to more tradional check valve, that had weight and a point on it to seal off accelerator pump pull over.

77 Ford F-150 with a 460 4bbl carb... the only problem with replacing it with a different brand carb is there is none unless you want to run a adapter plate. The new reman I one bought and returned to Holly was a bigger piece of junk then the original one on engine . Finally took it to a guy who I wish was still around and he repaired the base plate throttle shafts and a couple of other issues and it work great but it still had a starting procedure I figured out for when it was cold.

JUST one more thing.. These were notorious for flooding and backfires🤦‍♂️ My neighbors LTD had a “burn” spot over the center of the hood where there were a few fires. Usually in the morning. Crank.. then “boom!” “Honey, the car is on fire again..!😆🤦‍♂️“

@thewiseguy3529

2 жыл бұрын

Timing was off if it did that. Not the carburators fault.

Carburetor was a bad word at Ford from 1965 until they switched to Fuel injection, Every one of there Carbed 6 cylinder engines Were a disaster because of there Carb.

@ahoneyman

2 жыл бұрын

Motorcraft 2bbl carbs were pretty good.

The good thing about a ford with 4 barrel was you could bolt on a Holley and for get all your problems , That is what most ford guys did.

Boy, that filter sure does look delicate, I'll bet the casting cracked and broke often when installing or removing filters/fuel line. And that crazy float/duel inlet needle set up does look peculiar.

I have no idea what 4 barrel carb was on my 1970 Mercury Montego MX with the 351 Cleveland V8, but it performed great and ran like a scalded cat. Sure wish I still had it today.

When are you going to do a video on gm diffs,Can't wait for that one.

The 77 LTD Landau my parents had had the 460 with the 4350 Motorcraft carb. The spreadbore version of the 4300. That car always ran great, they seemed to never have problems with the carb on that car. Always started, had great power, wasn't too horrible on gas. However, after that car was lost to a bad wreck, their next car was a 1980 Mercury Marquis, 351W with the Variable Venturi. They HATED that carb! They had to have it worked on several times before they took it somewhere that fixed it right. But by that time the AOD transmission was going out, it needed a paint job and Mom wanted a brand new car. They traded it for a brand new 1992 Grand Marquis. But that 80 ran great the last couple years we had it, but there were many years of endless cussing and frustration lol. I'd like to hear your opinion of the Motorcraft Variable Venturi carb.

I worked for a 2 way radio shop in minnesota. the owner thought ford was great stuff. we had an old 64 heavy duty econoline. It had nearly 100k on it. the carb got bad so he insisted the ford dealer replace it with a new "ford" carb. one of the techs was starting it and it backfired causing an underhand fire. we quickly put it out. I took the truck to a independent repair garage down the street. they put a rebuilt holly on it. worked great. my boss wondered what happened to his wonderful ford carb. he went to the repair shop and there it was in the trash barrel. he took it back to ford for a refund. the 70s ford vans we had (all 6 cyl stick shift). to get the truck started you had to floor it and crank. big cloud of black smoke and sputtering till it settled down. the ford carb looked like a holly but they were crap.

I've never worked on a Ford with one of these. They're always swapped out. I had a 800CFM quadrajet that a backfire split at the secondaries to the primaries on the top

My best friend's parents used to have a 74 Torino and the transmission went out at 14,000 just outside warranty and it had to be rebuilt. They were not very happy.

@chaosdemonwolf1

2 жыл бұрын

C-4 or C-6?

I never really dealt with Autolite 4v carbs. I’ve driven a few 2Vs that tended to bog when stepping on the gas. I had a 75 Pinto wagon 2.3 4 speed with a Holly Weber 2v. It was bad when I got the car. I replaced it with a new carb which had the same problem. Ironically it still managed to start easily in sub zero weather. When Ford went to Holly 4vs in the 80s that was improvement.

I have a 67 Ford XL convertible with a 428 with only 35,000 miles, the original owner said he had nothing but issues with it, I rebuilt it myself the car will not run with the 4300 carb. I put a Autolite 4100 on it and it runs fine.

I had a 73 Mark lV with this carb. Must have had someone rebuild it that knew what they were doing as I got 14 MPG driving it home at 70 MPH. but, something(This was awhile ago) went bad with the carb, and it was leaking gas out the top. When I mentioned this issue on a Lincoln forum they said what was bad, but...it wasn't in rebuild kits and would need to find a good donor carb to replace said part. Knew that wasn't very likely so put on an Edelbrock. Ran much better, but...couldn't get more than 12-13 on the highway with it

@RareClassicCars

2 жыл бұрын

Yep. Likely secondary needle and seat

The variable venturi carb was even worse. I can't tell you how many of these were replaced by regular carbs. As a mechanic I would not rebuild one of these, it's an automatic comeback.

You should get into contact with Tyler’s forgotten car rescue and do a collaboration. You and him are on a very similar wavelength it would be great to hear you guys bounce thoughts and ideas of each other.

Just a note 6:00 even a Holley Dominator is fed by 6 psi.

I replaced a 2100 accelerator pump on Tuesday. Piece of cake

I have 4350 it super great works better than any carb I've tried.

I often wondered why the 335-M engines only came as 2 barrels. Maybe cause they came out about the time ford finally realized how crappy the 4300 was. I have a 1980 f350 with the 400 2v and it runs awesome.

I also expected this to be about the dreaded Variable Venturi!

Two carbs I like are the Dominator and the Weber 36 DD. Quadrajet, Motocraft 4bbl and the weird single barrel Chevy/Jeep Carter carbs no like.

Ford undercarbureted everything. The Autolite 2100 in my old '68 Cougar had some bad heatsoak, even back in the 1990s. The Motorcraft 2150 from my old '82 Mustang GT was pretty good. Any Carter YF tips?

Great vid,video, what about the VV 7200 I'd say that one of the worst carburetors from FMC.

Hello Adam! I would like to know your opinion about the Thermoquad carburetors. Kind regards from Mallorca, Spain 👍

I have an original 1970 Thunderbird, and I agree with you 100%. Surging on highway (too lean), hot start issues, flooding. But, swapping over to an Edelbrock, where do you hook up the kickdown rod of the C6 trans, or do you leave it off?

@RareClassicCars

7 ай бұрын

I believe there’s an adapter bracket

@valonkanava

7 ай бұрын

@@RareClassicCars Thanks for your quick reply! I am your follower from Finland

I guess this is why some of the 429 Cobra Jet/Super Cobra Jet (don't remember which) came factory equipped with a Rochester quadrajet in the early seventies, the old 4300 just wasn't up to the task!

@JOHNKESSLER88

2 жыл бұрын

You're right but the 429CJ had the quadrajet and the 429SCJ had a holley.

@dieselbronco9247

2 жыл бұрын

@@JOHNKESSLER88THANKS! I could not remember which was which but it would make more sense for the SCJ to have the Holley carb. I'm just happy I wasn't the only one to remember the quadrajet on the 429!

@paulkirkland1535

2 жыл бұрын

Yes,I remember when Ford did this in '71. Actually I was told there was a strike at the Motorcraft plant where these carbs were made. I had a '74 GranTorino which I replaced the Motorcraft 2100 2V carb with a Q-Jet from a '73 Olds 400 V8. The car ran like a jet plane and I could for the first time bury the speedo past 120 mph! 4 doors & 4 barrels is what I called that car since the swap.

I heard that the secondary air-valve springs can lose tension so that they open too easily creating an overly lean condition upon acceleration resulting in bogging.

Q jets seem to be able to take almost as much as 10 psi and not be near as sensitive to a little higher fuel pressure

The Edelbrock carb was nothing more than a renamed Carter, their claim to fame was the Carter Thermo-quad a big black plastic bowl , aluminum throttle body and cover about the same size as the quadra-jet , yeah Carter made somequadrajets when Rochester couldn't keep up with production. I really don't remember but the rochester slobberjet wasn't any bigger than a 600 cfm Holly mechanical secondary. I put a 650 mech. sec. on a stock cammed gm and it would fall on its face, got a police pursuit cam from Olds. for a '64 330, changed the rear gear to 3.9 . It was and F-85 2 door 2-speed and it would still only do 90 in the quarter, BUT put the 2.78 gears back in and picked up 10 miles per hour, the cam was designed to produce strong low end performance which is what you need for a long gear. The higher gear increased top speed to over 120 which was very scary in a 10 year old '66 F-85, I had a '69 cutlass W-31 little brother to the 4-4-2, by the way out of 10 people on here 9 of whom are professional mechanics you are the first person I've heard pronounce Edelbrock correctly, they aways put the L right after the first E. Oh I know what 4-4-2 stands for do you , all the young men I've talked to over the years tell me it's the size of the engine, I tell them what it really means and they get so embarrassed they call me a liar and other colorful metaphors, but I'm 70 years old and had a good telephone relationship with Oldsmobile I'll just call it their high performance I can't think of the office I called all the time. but they helped me put together one tough engine.

I sure could use your advice on my quadrajet 4,bbl carb on my 1978 Cadillac coupe DeVille it's only got twenty Three thousand miles on it I inherited it from my great uncle when he passed away in 96 I got it in 97. It's got a 425 Cub Inch in it I thought about buying a conversion kit and changing it over to fuel injection do you have any thing good to say about that I'm not really farmiliar with it

My dad was a big Ford guy until he had a very troublesome 87 F350 460 V8 that had a bunch of front end issues...however he said on his late 70s and early 80s Ford trucks he used to keep spare "black boxes" which I'm assuming is the electronic ignition control module...I guess they would fail on him often, the dealer told him it was because they got hot and the electronics degraded...let me know if you guys have any info on these thanks

What’s the main culprit for sticking secondaries? I have experienced this several times on my 4300 D and it’s scary

If you do an Internet search for the Motorcraft 4300, it usually comes up with the 4300 Autolite. Are they different? My 1971 Ranchero 351C 4V had a Motorcraft branded carb. Put on a Holley replacement, but it did not run any different. None of the stated problems, but the Motorcraft was not used very long.

@RareClassicCars

2 жыл бұрын

Same thing.

I could never understand why Ford just didn't re-engineer the Autolite 4100. The 2100 was essentially 1/2 of one and they used them clear up into the mid 80's with several revisions (2150 then the feedback version). The 4100 was an outstanding carburetor and they made a reasonably large CFM version for the 383 hi-torque Edsel engine in '58, I believe (the 1.19). I have 2 barrels that have a 1.24 venturi. A 4 barrel version of that would have been big enough for most big blocks. It has been perplexing to me as to why they made the 4300 series. Totally unnecessary.

Adam appreciate the info! I'm considering swapping my 78' Marquis 460 carb for a Edelbrock AVS 2 any thoughts, thanks

@RareClassicCars

2 жыл бұрын

Edelbrocks are great. I use the 1400 series.

This carburetor put fix or repair daily in ford. Aftermarket carbs or an EFI conversion would fix it.

👍👍👍

What about the Ford variable venturi

4100 was really good when I used

I wonder if the Stromberg Aeroquad was any good. They quit making them, so that’s a clue. Apparently they were OEM on something, I’m just not sure what.

I thought for sure this was about the Variable venturi