1939 Mercury w/ 59ab-engine ticking

W

Wils1514

Junior Member
So I just bought a 1939 Mercury coupe with a 59ab flathead. This is my first flathead and I have been doing some research on them. I’m not sure about the internals of this engine or mileage.
It has a noticeable tick that I am thinking is the valve adjustment. The car currently has an electric fuel pump. I have read it could be the fuel pump pushrod if it is still present. I know I’m going to have to do some digging into this engine to figure out what it is but I was wondering what else could be the cause. Oil pressure is about 50 psi at cruising and around 15 psi at idle.
I do have a video of the engine idling but do not have enough posts to have a link.
 
You can probably locate the tick with a sounding rod. I use a huge 18" screwdriver, or a long socket wrench extension. Put one end to your ear and then touch the other end to various places on the engine, as it is running. Like at the base of the fuel pump at the rear of the intake manifold. And at each intake and exhaust port location along the top of the engine block, at the edge of the intake manifold. If it is a valve you will hear the ticking noticeably louder when the touch point is near the noisy valve.



That said, the valves will tick with the valve clearance only a little greater than the specified amount. It may not need to be adjusted. After you locate the valve, run a compression test. If the cylinder with the tick is not noticeably lower compression than the rest, you might just be able to live with the ticking.


The '53 Merc engine in my '34 pickup has a little tick at idle, which I have lived with for five years, and had no other problems.
 
Thank you! I'll give that a try. I was planning on doing a compression test just to see what kind of condition the engine is in anyways.
 
I started removing plugs to get ready for the compression test. Looks like the water pump almost cut through one of the plug wires…
 

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Good find! You can use small zip ties to bundle those plug wires and keep them away from the belts.
Welcome to the forum.
 
Well the compression results are good. All are between 120-130.
Looking at the plug wires it seems they are copper core wires. The car has been converted to 12v and has a Mallory electronic ignition. I’m probably going to replace those while I’m at it. Once I get that done hopefully the tick has been resolved.
 
Make sure you use the type of wires recommended by the ignition manufacturer. Most of them specify one type over the other, but I really don't remember what it is as I am strictly a "points guy".
 
tubman said:
Make sure you use the type of wires recommended by the ignition manufacturer. Most of them specify one type over the other, but I really don't remember what it is as I am strictly a "points guy".
Click to expand...

Mallory recommends spiral cores according to their instructions.
 
120-130 psi on a stock 59A? Someone has been messing with the heads and it sounds like they did a pretty good job too.:D
 
tubman said:
120-130 psi on a stock 59A? Someone has been messing with the heads and it sounds like they did a pretty good job too.:D
Click to expand...
Yeah I know next to nothing about this engine and the previous owner didn’t know much either.
Here’s what I got for numbers:
1:125
2:120
3:120
4: 125
5: 120
6:125
7:120
8:130
 

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drolston said:
Did you ever try to pinpoint the location with a sounding rod?
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Yes I did poke around a little bit. I want to say its coming somewhere in the area of cylinders 3&4. I placed a screwdriver on the intake/head area and the other end to my ear and I think the tick intensified. I'm guessing pulling the intake is the next move.
 
The higher than normal compression figures leads me to predict that once the intake is off, you will find a set of adjustable lifters. It seems that some of the later ones have a tendency to loosen up by themselves.

It will be interesting to see what you find.
 
Thanks everyone. I’m sure once I get to that point I will have some more questions. I’m use to working on sbf’s, not flatheads so I appreciate the guidance.
 
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