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'49 Dodge, clicking under hood and power loss

I have a 1949 Dodge B1-B, which was the half-ton model. Still has the original flathead, straight six engine, been rebuilt twice to my knowledge. Three-speed in the floor. I have done most of the restoration myself, aside from putting in another transmission and swapping out the rear differential, but I am by no means a mechanic with adequate diagnostic equipment; I don’t even have a stethoscope.

My problem is this: Over the course of about three days, I noticed a clicking/ticking noise from under the hood which gradually got louder. Once it reached its full noisiness, I noticed a marked loss of power across the board. I have also noticed a little bit more vibration that normal, but only enough to make the mirrors shimmy a bit.

Things I have fixed/replaced since the noise started:
-New spark plugs
-New condenser coil
-New distributor cap
-Rebuilt carburetor (it needed to be rebuilt long before the noise started)
-New glass-packing for muffler

I have also adjusted the timing with the distributor shaft adjuster and the idle screw, but the ticking doesn’t go away.

There has always been a leak in the exhaust system where the manifold meets the pipe, and the heat riser is naturally broken, but these things have always been present and there has never been this ticking noise.

I can get it to idle as low as 250-300rpm, so I don’t think it is a fuel issue. And from what I can find online, the easy fix would be that the timing chain needs to be replaced. I am getting this checked by a mechanic on Monday.

I have put maybe 100 miles on it since the noise and power loss started, and it doesn’t seem to be getting worse over time. So, does anybody have any suggestions on what might be causing this?

The first thing I would check is the timing chain. If the chain skips a tooth or two it’ll cause both the valve and ignition timing to be off. And if the timing chain has jumped time because it’s stretched the noise you hear could be the timing chain hitting the timing chain cover.

Tester

Did those old 230 flatheads use a chain or just gears to drive the cam?

My dad had a 1949 Dodge sedan and then a 1952 Dodge coupe. Both engine developed this clicking noise and it was the exhaust manifold gasket. The escaping exhaust does make a sound similar to a clicking sound. This was years ago, but it seemed to me after the gasket was replaced, the car seemed peppier. The exhaust manifold gasket was a common problem with the 230 cubic inch 6.

Have you adjusted the valves?

With the engine running, run your hand around the edge of the head gasket and feel for a leak. An alternative would be to try a spray such as WD40, you should see the puff in the mist of the spray. Even a pump spray bottle of water might work, as long as it gives a good mist.

And then, there are the spark plug wires to look at. Check at night, if arcing, it will be more visible.

I think yours has a chain. Can you probe around with an automotive stethoscope to see if you can pinpoint the area where it may be coming from?
It could be that the starter is partially engaged but that wouldn’t explain the loss of power. Maybe the distributor is on its way out - those centrifugal weights are floating around in there, maybe?

Btw, there’s a forum dedicated to trucks like ours*: http://www430.pair.com/p15d24/mopar_forum/forumdisplay.php?f=8

*(I have a 52 B3B truck, btw)

I like the spark plug wires suggestion - how old are they?

If a spark plug wire is failing and causing the clicking noise you can see the spark going where it should not oughta go in the dark. Sounds reasonable to me, the best way to find the problem is find the source.

I suspect bad wires also, have you found the prblem yet??

It sounds like you have a tappet out of adjustment or the cam is wearing out. I’d try to adjust the tappets