I blew it up!

[jim1932]

An eventful day today, finally got around to trying to get the car on the road. Checked the timing, spot on. Car seemed to want to flood tying to get it started...then back fired and ..OH Shit fire.... Yes we had a fire extinguisher handy and the fire was on the floor not the engine.....

Then we swapped for a brand new model A carb of a model A.... Turned it over, Nothing ,,nothing BOOM A little inspection and the picture tells what we found... That is the muffler (photo is bottom side up).... this car has run before, what the heck is going on? Timing gear?

[BLACKNRED]

Timings way out.

I did the same to 2 mufflers connected to a 390 FE BBF, my ears were ringing for a couple of hours.

[mrtexas]

Too rich and got gas in the muffler. Do you know how to start a Model A/B?

It should start on the 1st or 2nd revolution of the engine.

When I first got a Model A it took me a while to figure out how to start it.

Forgive me if you already know:

- put spark all the way up
- turn on gas shutoff
- close GAV all the way and open one turn
- turn key on
- pull out GAV
- hit starter
- let go of GAV
- should start on first or second rev or something is wrong

I have a timing gauge(all the usual suppliers have them) on both my model As and have a white mark on top dead center on the crank pulley so I can use a timing light to time. I never could get the timing
right without a timing light.

[oldford2]

Reminds me of 60 years ago in high school. My buddy had his drivers license and could get his father's 50 Ford sometimes. Great fun spinning the tires and racing around. On long downhills he would turn off the ignition and at the bottom turn it on to get a loud boom from the muffler. Great fun until one time the muffler blew apart! His father was a kind and forgiving soul so Peter kept using the car. Tore out a clutch once in the mountains and also slid into a tree after a snowfall. Oh, I could go on with stories of how we drove back then. Another friend had a 30's Chev coupe and how we didn't get killed riding in the rumble seat at 60 mph is beyond me.
John

[machine girl]

a little of both ? timing off and over choked it/ our timing indicators on ebay, stainless real nice,.

[jim1932]

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A b doesn't have Spark and GAV right? The timing was set by a Model "A" expert using the 32 red book. We used the PIN and set it so it sparked exactly wen the pin slid in. It was definitely flooding out. Almost like the pump was too much for it.

Suggestions?

[DavidG]

Jim,

As you obviously know, starting a Model B is quite unlike starting a Model A, at least in terms of the controls. Do you have a four-cylinder owners manual? If not inexpensive reprints are available. Follow the starting procedure exactly. If your carburetor and fuel pump sat over the winter with gasoline in them both are likely clogged up in various ways from the breakdown of the gasoline. They both should be disassembled and cleaned with lacquer thinner or other suitable solvent that will cut the goo. That should eliminate what likely is a stuck (open) float valve in the carburetor that is causing over fueling.

Dave

[mrtexas]

Originally Posted by jim1932

A b doesn't have Spark and GAV right? The timing was set by a Model "A" expert using the 32 red book. We used the PIN and set it so it sparked exactly wen the pin slid in. It was definitely flooding out. Almost like the pump was too much for it.

Suggestions?

A B has a GAV. It is the choke rod. Turning it adjusts mixture.
Procedure is the same for starting a B as an A but without the spark step. I run a B carb on my A. It wouldn't hurt to check timing with a light. I was unsuccessful setting timing by the manual method for an A. Glad I checked the timing with a light.

The timing pin can line up 180 degrees out as well as correctly. On an A the pin lines up at top dead center. On a B it is 19 degreesBTDC:

http://www.fordgarage.com/pages/ignitorB.htm

[jim1932]

Based on the photo's on Vince's site it looks like we were 180 degrees off.

Also, no matter what I seem to do with carbs and Fuel pumps, they seem to leak gas like crazy. Are the gasket sets not any good? What happens to the pressure when the float is closed but pump is pumping?

[itsa52]

I have a pit in my garage was working on an old Pickup while in the pit and it blew.. Door was open, and the neighbor and wife came running but were afraid to look in the garage fearing I was gone.. We still laugh about that

[jim1932]

Originally Posted by itsa52

I have a pit in my garage was working on an old Pickup while in the pit and it blew.. Door was open, and the neighbor and wife came running but were afraid to look in the garage fearing I was gone.. We still laugh about that

Well I was in the drivers seat with the number 2 floor board off. Fortunately the Muffler is a little further back and the windows were down a bit. It was Loud

[hardtimes]

Originally Posted by jim1932

Well I was in the drivers seat with the number 2 floor board off. Fortunately the Muffler is a little further back and the windows were down a bit. It was Loud

Hey jim,
Sounds like a combination of few things to cause what you picture.
However, TIMING is major input that is most likely wrong. As in..when you keep cranking / choking, and the spark finally gets 'there' at the wrong time...boom !
Can you show a few pictures of your setup, i.e.- carb and front time plate.
Question: Did you rebuild and put in new cam/crank gears ?
Note: If using original distributor...the rod/dist can only go in one way, BUT your four plug wires have to match firing order. And, of course, even if wires/dist are correctly installed...far off timing setting (cam lobe) can make your engine run very badly and very HOT.

[DavidG]

Jim,

The pump has a pressure relief valve. It won't pump gas through the line unless the float valve is open.

Dave

[rotorwrench]

The timing might be off but a stuck exhaust valve can keep the way open for ignition to light off fuel vapor in the exhaust too. A compression check will find a stuck valve. The timing pin in the recess should be correct. The cam shaft only turns once for every two crankshaft rotations.

[jim1932]

Originally Posted by DavidG

Jim,

The pump has a pressure relief valve. It won't pump gas through the line unless the float valve is open.

Dave

Where is that? Is it possible that it is stuck?

[DavidG]

Given the goo that forms when modern gasoline breaks down, that's a distinct possibility and why I recommended (above) that you completely disassemble and clean both the fuel pump and the carburetor. Both valves in the fuel pump are in the upper die cast body of the pump. There's a seat, a spring, and a hex-shaped disc of the same brown plastic-like material used for the timing gear. That said, you could still have a problem if the float valve in the carburetor is not seating properly or the float level is set too high.

[jim1932]

Hmm, I guess I thought that disk was a one way valve to pump the gas. I have the carb off and will clean it out before I try it again. I have a spare pump, but the lid doesn't seem right, it hits the brass seat before it is down far enough to seal on the cork gasket.

[VeryTangled]

Bummer Jim! I know you've been workin real hard to get your car driving. More parts, ugh.

-VT/JeffH

[PeteVS]

Originally Posted by jim1932

What happens to the pressure when the float is closed but pump is pumping?

I'm pretty sure that the spring in the pump pushes against the diaphragm to push gas to the carb. The eccentric on the cam only pulls the diaphragm back to draw more gas from the tank. If the carb doesn't accept all the gas that the pump is capable of passing, the diaphragm simply stops moving before it goes full stroke. It should be the spring force that determines the pump outlet pressure. I think that over pressurization in fuel systems is caused by poorly made fuel pump springs with forces that are too high. Of course, this is only my humble opinion.

[DavidG]

Pete,

You're correct, but it's difficult to diagnose unless you know the original specification for the spring.