Time for a timing adjustment?

[Squadron]

Hey folks!

My 47 Ford just got back from the shop where they did a few things for me that I didn't have time to do:

• Resolved some coolant leaks (antifreeze is nasty stuff) and remounted the new radiator
• New carb
• Added a radiator overflow

However after a few weeks of sitting without driving the car now has a pretty nasty habit of pulsing while the engine's cold. It also runs somewhat rich (not thick clouds of black smoke, but black-ish).

I took some videos of the engine running so you can hear the sounds and get a good view of what's going on. You can see it here:

https://youtube.com/shorts/F-8ShsKjPT8?feature=share

I fiddled with the two carb knobs and there was 0 change in either the pulsing or the smoke, and it's more pronounced when the carb is choked off (valve is closed). When I remove the air filter entirely and open up the choke, it feels less pronounced but is still there.

As the car warms up, the pulsing gets less pronounced but the smoke persists regardless.

I'm thinking I might need to do two things:

1. Fiddle with the carb more to get the engine running less rich (somehow, I'm really not an expert on carbs).
2. Maybe adjust the distributor timing? Also don't know much more than the theory around distributor timing. From what I can tell, I'd need to pull off the radiator again to get at the distributor.

If I have to do #2 I'm wondering if I should just fully swap out the distributor with one of these:

https://cwmoss.com/collections/v8/pr...t-12v-negative

The idea is to increase the reliability of the car without ruining the character of the engine so making the distributor less maintenance would be a win.

Any feedback would be welcome!

[Tim Brown]

I wouldnt run that new efire distributer if you paid me. Ive been running stock distributers for 30 years with very little trouble. Have someone with a sun machine set up a stock one with good quality points and condenser and youll be happy... My opinion. Free advice is worth what you pay for it.

[Tim Brown]

Where are you located? Let me know if you are in NorCal...

[tubman]

I'd also recommend NOT adding a flakey aftermarket distributor into the mix.

[hueyhoolihan]

i would turn the two idle/mixture screws all the way in (gently) and unscrew them about one full turn on an aged carb, and maybe 1 1/2 to 2 full turns on a newish carb. i've found that aged carb's idle/mixture holes become enlarged as the decades pass) but before that, i would remove and clean the sparkplugs...

then make sure, after the engine has warmed up, that the choke is NOT on (i.e. the large butterfly at the top of the carb is straight up and down).

that should be a good starting point to begin with. if it's still showing massive amount of black smoke, i'd be checking the plugs again and if they show evidence of fouling i'd be pulling the carb off and disassembling it to find out how the excessive gasoline is getting into the intake manifold. could be just about anything. (i.e. loose jet, wrong jet, bad float position, etc.)

as far as the lope is concerned, i wouldn't worry too much about it.

[Ggmac]

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Is it an original carb ? How did it run before the carb change ?

[kurt v]

said new carb was put on, put the old one back on.

[38 coupe]

My thoughts for whatever they are worth

• The video sounds like a motor running very rich (too much gasoline).
• Fix the last thing touched! The car worked, got parts replaced, and now has a problem. Don't replace more parts, fix the problem that got added during the last work done. I see this often and don't understand it. Work done is no guarantee of success. Adding more work without diagnosing the problem will just compound the problem and make figuring it out that much harder.
• The air cleaner in the video is the modern small element type known to flow like crap. Recommend replacing it with an original cleaned up with oil in it (oil bath type).
• The carburetor in the video looks like a new chinesium type. I have heard mixed, but mostly negative, reviews of these. I have no personal experience with them. I would rebuild the stock carburetor, it is tedious but not hard. Cleanliness is necessary. Let us know if you choose to do this, there are a couple tips that can make a lot of difference.
• The factory distributor is a great unit. For a flathead that is not a race type motor you will not improve it by using an aftermarket distributor. Many aftermarket distributors offered in the last 30 years have problems, such as electronic parts that will fail and advance curves that don't match a flathead's needs.

One other note, you have the mechanical fan hub but no mechanical fan. I would put the mechanical fan back on. If you plan on relying only on the electric fan you can take the mechanical fan hub off and remove the belt, it isn't doing anything for you like it is now.

[Ggmac]

I checked his earlier posts and it seems he had this problem for awhile. I’m just guessing here , so more information is needed from the op.
Adding new / different parts to the equation just adds more money / time to properly diagnose running issues. Keep it simple , one item at a time .
I suggest a vacuum gauge to help diagnose. If its a new carburetor, remove it and disassemble, clean and check jet size , power valve ( if equipped) , adjust float and general clean it .

[Squadron]

Thanks for all the help so far, I took some time last night to make sure my horses weren't panicking from all the fireworks and then poked at it a bit more today. Some further information:

I wouldnt run that new efire distributer if you paid me.

Fine by me, that saves me $500 and however many headaches I'd have.

Where are you located? Let me know if you are in NorCal...

Nope! Outside of Portland a bit (Oregon). I typically buy stuff from Cal though, good parts people there.

i would turn the two idle/mixture screws all the way in (gently) and unscrew them about one full turn on an aged carb, and maybe 1 1/2 to 2 full turns on a newish carb. i've found that aged carb's idle/mixture holes become enlarged as the decades pass) but before that, i would remove and clean the sparkplugs...

then make sure, after the engine has warmed up, that the choke is NOT on (i.e. the large butterfly at the top of the carb is straight up and down).

Solid advice here. I'll do that and report back. Some further information about the carb:

It's definitely some weird carb that a previous mechanic tossed on there. I hate carbs and know nothing about them so I had no idea what he was putting on there. Live and learn. The carb it replaced wasn't the original either, it was a different replacement of the OEM part.

I'll try to dig up something, but I'm open to advice here if anyone has a recommendation. From what I can tell it looks like I'd be looking at this guy from CW but I can't tell if it's Chinese or anything:

https://cwmoss.com/collections/v8/pr...uretor-1938-48

The previous carb had a serious stumble at high RPM, and with the new carb I didn't notice that at all.

The video sounds like a motor running very rich (too much gasoline).

You're not kidding - the other giveaway is the cloud of black smoke out the exhaust when I hit the accelerator. Probably a good thing for making a quick getaway but terrible for literally everything else.

Fix the last thing touched! The car worked, got parts replaced, and now has a problem. Don't replace more parts, fix the problem that got added during the last work done. I see this often and don't understand it. Work done is no guarantee of success. Adding more work without diagnosing the problem will just compound the problem and make figuring it out that much harder.

Yep noted for sure. Not gonna mess with the distributor. The things that were last touched were the spark plugs and carb. As I mentioned above I'll look for a more original carb, that would definitely have the right jets and adjustments and probably a better filter to get more air in.

One other note, you have the mechanical fan hub but no mechanical fan. I would put the mechanical fan back on. If you plan on relying only on the electric fan you can take the mechanical fan hub off and remove the belt, it isn't doing anything for you like it is now.

What I really want to do is remount the radiator to give me more space and put the fan back on. But you're right - that belt is doing nothing right now. Well, except robbing the engine of like a whole HP or something.

So all in all:

1. I'll clean off the plugs and grab pics of them anyway. I'm almost positive they're pure black, but the plugs are new (less than 10 miles on it).
2. I'll readjust the knobs on the carb to a known start point (2 full turns from all the way in)
3. Start looking for a more standard, less crap carb.

Thanks for the help and breakdown folks. As you can tell this is my first old car and I'm making lots of mistakes but learning a lot too. I'll stay away from the distributor for now.

[Squadron]

To provide more of a summary of what's been done:

Originally when I bought the car it ran OK but would seriously stumble as I pressed the gas. It also overheated really quickly.

I got the original radiator cleaned out, that didn't fix it. Ended up pulling out the radiator completely, pulling off the water pumps. Turned out one of those was completely broken (impeller was literally shattered). Replaced those, put all the cooling back together.

I also had the mechanic look at the stumbling. They replaced the plugs, tried cleaning out the carb twice, and eventually replaced the carb completely with what's there now. I also bought a new fuel pump (thinking the stumble might come from that) but that turned out to not be necessary after the carb was swapped with the one that's in there.

Got the car back, drove it a bit. For about a month or so it was fine, then it started running like it does now.

So it's time to undo a bit of what the mechanic did. Oh well. Live and learn.

[tubman]

Originally Posted by Squadron

To provide more of a summary of what's been done:

Originally when I bought the car it ran OK but would seriously stumble as I pressed the gas. It also overheated really quickly.

I got the original radiator cleaned out, that didn't fix it. Ended up pulling out the radiator completely, pulling off the water pumps. Turned out one of those was completely broken (impeller was literally shattered). Replaced those, put all the cooling back together.

I also had the mechanic look at the stumbling. They replaced the plugs, tried cleaning out the carb twice, and eventually replaced the carb completely with what's there now. I also bought a new fuel pump (thinking the stumble might come from that) but that turned out to not be necessary after the carb was swapped with the one that's in there.

Got the car back, drove it a bit. For about a month or so it was fine, then it started running like it does now.

So it's time to undo a bit of what the mechanic did. Oh well. Live and learn.

I don't know why you would say this. Since you said "For about a month or so it was fine", it seems he fixed it. Either what he fixed didn't stay fixed (most likely) or something else went wrong. It sounds like you have some trouble-shooting to do.

[Squadron]

Originally Posted by tubman

I don't know why you would say this. Since you said "For about a month or so it was fine", it seems he fixed it. Either what he fixed didn't stay fixed (most likely) or something else went wrong. It sounds like you have some trouble-shooting to do.

Because I suspect that the carb he put on there isn't the right one for the car, or at least it doesn't have the right parts attached (air filter, maybe jetting). I also doubt my own memory of "fine". I don't think I even noticed how rich it was running because I was just happy to have it not surging on acceleration anymore.

It was running ok - not perfect, but not horrible. I didn't really do much between getting it back and now aside from run it a few times.

It's definitely running rich though. I cleaned off the plugs (they were pitch black) and they went black again in about 5 minutes of running. Adjusting the screws made the engine sound better but it didn't make a difference to how rich it ran (black exhaust clouds when I'd rev).

So ultimately it's probably less about undoing it and more about figuring out what about the carb is wrong. Since adjustment screws don't seem to make much of a difference I'm going to clean it up. I'm getting good spark, and even if I completely remove the air filter the exhaust stays black.

Of course it could also be the timing. Hence why I was thinking it might be time to think about the distributor. Adjusting, not replacing.

[Ggmac]

New fuel pump could be putting too much pressure out , causing the rich running . Its just one possibility, next I would check the float level in the carb , again would cause rich running. The next would be the power valve . Gotta run more later

[petehoovie]

Originally Posted by Squadron

2. Maybe adjust the distributor timing? Also don't know much more than the theory around distributor timing. From what I can tell, I'd need to pull off the radiator again to get at the distributor.

Any feedback would be welcome!

You don't have "to pull off the radiator" to remove the distributor...

But stick with your troubleshooting of fuel delivery problems...Excellent tips from Ggmac above...

[38 coupe]

It sounds like you are relying on a shop that is not familiar with vintage Fords to do the work for you. Have you thought about doing the work yourself? There are many of us on the Ford Barn that can talk you through carburetor and distributor work. If you don't want to do that there are a few recommended people that rebuild the factory carburetors and distributors with good results. I think the modern shop is not the best place to get your car working like it should.


Stumble on acceleration is usually the accelerator pump not working, or the accelerator discharge nozzles clogged up. Installing a gasket kit with a new accelerator pump in the carburetor, along with verifying everything matches, works wonders. Since you have the earlier front distributor / center water outlet type engine you don't have to worry about distributor to carburetor vacuum advance matching. Any Stromberg 97 or Chandler Groves / Ford / Holley 94 type carburetor from a 38-53 Ford can work on your engine. The 38-48 versions are better for your car since they should have the hand throttle pieces that match your dash controls.

[Squadron]

Originally Posted by petehoovie

You don't have "to pull off the radiator" to remove the distributor...

But stick with your troubleshooting of fuel delivery problems...Excellent tips from Ggmac above...

Good to know! I kind of assumed since it would be hard to get at it and all of the videos I find have the radiator removed. That might just be for visibility though.

The fuel pump is an interesting thing. I bought a new electric fuel pump thinking that the old one might be dying, but it didn't get installed. However, there could still be a delivery problem. From what I can tell, it's got the original mechanical fuel pump. Which if I understand correctly, should be delivering the correct amount of fuel to the carb.

I just spent about 30 minutes crawling under the car just to make sure there wasn't a separate fuel pump ALSO shoving gas in, since previously there was a fuel regulator in-line too (but the mechanic removed it).

Is there a way to measure the pressure of fuel into the carb? Or measure the timing to see if it's off?

[Squadron]

Originally Posted by 38 coupe

It sounds like you are relying on a shop that is not familiar with vintage Fords to do the work for you. Have you thought about doing the work yourself? There are many of us on the Ford Barn that can talk you through carburetor and distributor work. If you don't want to do that there are a few recommended people that rebuild the factory carburetors and distributors with good results. I think the modern shop is not the best place to get your car working like it should.


Stumble on acceleration is usually the accelerator pump not working, or the accelerator discharge nozzles clogged up. Installing a gasket kit with a new accelerator pump in the carburetor, along with verifying everything matches, works wonders. Since you have the earlier front distributor / center water outlet type engine you don't have to worry about distributor to carburetor vacuum advance matching. Any Stromberg 97 or Chandler Groves / Ford / Holley 94 type carburetor from a 38-53 Ford can work on your engine. The 38-48 versions are better for your car since they should have the hand throttle pieces that match your dash controls.

Honestly this is how I started out, but I rapidly realized I didn't have a ton of time to work on it. I'm getting that figured out now though.

I also wanted to give local mechanics some business since they always seem to have cars of this era out in their shop - but honestly I'm not really sure if they knew what they were doing.

[Flathead Fever]

First thing I wonder is how they set the timing up with an aftermarket distributor and no timing fixture to line it up with. We're getting to the point that most mechanics have never worked on points and carbs. and a pre '49 flathead is even worse. There are no timing marks on the engine, the distributors timing is setup in a fixture and then the distributer is mounted to the engine. We don't know what was done with your timing when the high-tech distributor was installed. I was mechanic during the points era, there is absolutely nothing wrong with points, except getting good quality replacement parts.

If you know the timing correct, I would turn the idle mixtures screws in all the way until they are closed (gently close them) and this should kill the engine at idle. If it doesn't it means the carb is getting fuel from somewhere it is not supposed to, like flooding over.

What fuel pump are you running and what pressure is its rating. Early Ford carbs cannot handle the pressure of modern fuel pumps. There are only couple electric fuel pumps with low enough pressure that will work unless you run an additional fuel regulator. It's always best to stay with the stock mechanical pump.

[fredM]

I had already planned today to check the choke while the engine was still cold. Cold at this time of the year is 68-72 degrees at wake-up. but I want that choke wide open in summer. Also, the adjusting screw adjustments is a good idea. It's Sunday, I don't work today, Got to do something nice for the car.