1946 ford with one dead cylinder
 

Need advise on ford flat head I have a cylinder that has a constant miss.I have checked the compression on all 8 cylinders.1@110 2@110 3@95 4@115 5@120 6@120 7@115 8 @110. 3 is the one causing issues I can pull the plug wire off with it running and no change in sound or how it runs. I have put a vacum gauge on it and it reads at 25 with a constant flutter of the needle. I know the valves are free because I have hade the head off and intake the bores did not look bad did have a ridge on the top of the cylinder but other than that looked fine don’t know if a valve is just not sealing or weak valve spring or just bad piston ring. The engine other than running on 7 cylinders does not run bad does not smoke when running.

Re: 1946 ford with one dead cylinder
 

IMHO it should run ok and on all cylinders with #3 being a bit weaker, but it should fire. Have you checked for spark on #3? Or maybe #3 spark plug is oil fouled or has a bad plug wire.

Re: 1946 ford with one dead cylinder
 

If you are getting good spark TO the plug, I'd suggest you change the plug.
If you are not getting good spark, then wire, inner cap, rotor???

Re: 1946 ford with one dead cylinder
 

I agree, when I was young, compression figures like that were a good reason to buy the car. I think that if you can find and fix what's actually causing it to run sourly, it may come back.

Re: 1946 ford with one dead cylinder
 

I'll never forget this. Way back in high school we had a flathead that had the same problem you have. Teacher said 'lets play detective' . Us kids smoked our brains finding nothing wrong its impossible. After all said and done, teacher said the problem is right in front of your nose -open your eyes! We all gave up. The teacher made lines inside the dist. cap with a lead pencil!! gotta be kidding Now thats real teaching.

Re: 1946 ford with one dead cylinder
 

Thanks for all the comments I am going to take the crab cap off and look at it for cracks and carbon. I hope it is something simple like that.

Re: 1946 ford with one dead cylinder
 

The issue is solved I think it was carbon in the cap took it off blew it out cleaned plug and wire. The tone of the engine is better and runs a lot smoother something simple.

Re: 1946 ford with one dead cylinder
 

Now that it's firing again, I'll bet the compression will come back, too.

Re: 1946 ford with one dead cylinder
 

Tubman has it right. A little flame in the chamber will help burn off the unburnt oil and fuel around the compression ring and things should get even better. Tim

Re: 1946 ford with one dead cylinder
 

run a little mmo in the gas to help clean up the rings/valves. sure helped me!

Re: 1946 ford with one dead cylinder
 

Yes the compression came up a little sure sounds a lot better.I did add a little MMO to the gas. I am just glad the issue was solved. Now to move on to the body work.

Re: 1946 ford with one dead cylinder
 

And while you're at it, dump some MMO in the oil too. After sitting a long time this stuff really gets things moving again. Sounds like you have a real nice project!