Problem with my B-3-B

[Guest Saroni,V]

Hello. I have been spying on all the questions and answers on this forum for some time, having been able to get all my problems solved through it without having to ask any. However, I now have a situation that I just can't seem to solve, so please any thoughts will help.

I have a 1952 1/2T, b-3-b, 218cu., 6V that I have been working on for some 9 years. I have rebuilt the engine myself with help from some friends; an 'ol timer' and a helicopter mech.

Problem:

The truck runs great up to about 2500rpm and then boggs down in all gears. We beleive it is getting flooded.

A little history:

The crank flange was crack and I replaced it with a crank from a 235cu and replaced the connecting rod, which gave it a longer stroke length (right?) which from what I understand is the only difference between the two. The carb. is a rebuilt ball-n-ball, new spark plugs, new cables, new vacuum advance and line, new fuel pump(w/ 3.5 psi fuel line at the carb), old distributor, all new inter parts, old coil (6V), I think that's it.

Question:

Will changing the stroke lenght on the crank do this? Do I need to change the coil to a stronger one? Could it be the weights in the distributor?

Thank you for any and all replies.

[Tony_Urwin]

Great looking truck. It's easy to see that you've done a lot of work on it.

I guess your engine is now a 230 (or larger if it was bored oversize)!

Do you smell gas when the engine bogs down? Is that why you think it may be flooding? The same symptoms are sometimes the result of fuel starvation. The rust in these old tanks can be trouble for fuel delivery.

You can check the mechanical and vacuum advance with a good timing light and a vacuum pump, but I'll let the better mechanics advise you on that.

[Guest Saroni,V]

Thanks. This could be possible for the truck was sitting for about 7 years with gas in the tank. I have gone through the line and blown it out with air. Also, burned though about 6-7 tanks of gas now. Do you think this could be a problem?

[Guest jtw3749c]

If it were me, and the tank has been in it for awhile and you haven't looked into that area, I would take the tank out, clean and see what comes out of it. You never know what lurks in dark places.

[greg g]

Sounds like fuel starvation rather than flooding. Just for giggles, check the fuel pump. There is a fine brass screen in the pump in the lower chamber. This will get clogged with debris from the tank. Also if you haven't put in an in line fuel filter or two, you chould consider splicing on in before the pump and one after. If everything is clean, check for any air leaks on the suction side of the pump. Any air entering the system will make the pump much less effective at moving fuel from the tank.

A simple check is to disconect the line fromthe pump to the carb and check the flow rate. put the end of the lineinto a clear container, then with the coil wire out of the dizzy, have an assistant crank the engine while you count the pump strokes of the pump. 15 pump strokes should yield 7 to 8 ounces of fuel. Less in the container would indicate a blockage or air leaks in the line/pump.

[Reg Evans]

Another test might be to temporatily install a small tank ( lawn mower,boat, or gas can with outlet fitting installed ) in the bed of the truck. Run a temporaty line to the fuel pump and see how that works. If the problem goes away at 2500 rpm you know what to do.

[Guest Saroni,V]

Great, thanks for all the replies. It seems everyone believes it is a fuel problem and nothing to do with the change to a crank from a 230cu, a longer stroke, and bored out cylinders. One thought was that I needed to shorten the spark plug gap to .25...any thoughts about this? I will try out all your suggestions. Again, thank you.

[grey beard]

Another thought - you may be dealing with a plugged exhaust. The problem will show up only on a pull or at higher speeds.

This is easy to check. Hook up a vacuum gauge to your intake manifold and start the engine. If you accelerate up to the speed where it begins to miss, then drop it quickly back to idle. If the exhaust is normal, the vacuum needle will bounce quickly up to idle vacuum - 15 to 17 inches hg. If the exhaust is partially plugged, the gauge will come up to idle vacuum slowly and sort of sluggishly.

It is an easy test for a problem that has foxed a lot of good mechanics. LOL