‘53 ran hot, then missing badly. Head gasket?

[Bruce_MO]

Just took my ‘53 Ranch Wagon to a local show and had to wait in line to park for quite a while. Temp gauge climbed to H but didn’t boil over. Vapor locked but switched on elec pump and made it to the parking spot. When leaving the show, it ran very poorly, missing badly. Coil new, Mallory distributor set up by Charlie-NY very recently. Next day, still missing badly. Fearing the worst, I ran compression test. Engine is stock EAB with Offy heads and 2-2 intake. Values are:
#1… 90
#2… 91
#3… 90
#4… 100
#5… 90
#6… 84
#7… 85
#8… 90

I’m taking those readings as “ok” and not feeling I blew a head gasket. Would you agree? No other head gasket symptoms.

I’m going to put new plugs in it and fiddle with the Holley 94’s a bit, and hope it’s running better. Was planning on taking it to Auburn next week; hope it smooths out.

Thanks for any opinions.
Bruce

[jplutz]

Call Charlie...

[Fairlane514]

Is it a points distributor? If so, condenser may be bad.

[Bruce_MO]

It was a new Mallory condenser, on a dual point Mallory distributor. I have an older one that was not causing heavy misses, maybe I’ll try it.

Still waiting for confirmation that the compression values are good.

Thanks

[drolston]

How did the plugs look when you pulled them for the compression check? When you check the plugs, be sure they are not stock 7/16" thread length, which would leave the tip up into the spark plug hole. Conventional wisdom on HAMB is 1/2" thread length, and that is what I use on my Offy heads.
That said, my engine usually runs a little rough until is run under load for a few minutes to clear the plugs. Did yours run poorly all the way home?

[tubman]

Sponsored Links (Register now to hide all advertisements)

We had a long thread on here several years ago about the proper spark plugs to use with older Offenhauser heads. I believe the consensus was that nothing available was correct; 1/2" reach plugs were too short and would be shrouded. but 3/4" reach plugs were too long and would interfere with the exhaust valve. (There seems to be no such thing as a 5/8" reach plug.) I have a set of new, never been installed set of 8BA Offenhauser heads that I bought from Speedway in the mid nineties and can confirm this. The final consensus was to run the 3/4" reach plugs with a 1/16" spacer. I looked for the thread and, curiously could not find it. I believe that Offenhauser has since corrected this problem in it's later offerings. I would carefully check plug fitment when using any Offenhauser heads.

Here's the thread I was referring to : https://www.fordbarn.com/forum/showthread.php?t=272052.

[flatjack9]

Compression readings are acceptable. Not your problem

[cadillac512]

Originally Posted by flatjack9

Compression readings are acceptable. Not your problem

Exactly. No problem there. If it's a steady miss at idle, remove one plug wire at a time from the distributor cap. If one makes no difference, that is the cylinder misfiring. From there you check the wire, the plug and connections at both ends AND the point gaps. If it's a random miss the condenser is a good possibility as is a coil wire or distributor cap with a bit of coolant residue in it (got hot).

[Bruce_MO]

I’ve been using NGK plugs… B-6L. Saw them recommended on FB several years ago for Offy heads. They all looked the same, pretty dark, not oily. Car has always run rich and I’ve tried several combinations of jets and PV’s. Per Charlie, now running with PV’s blocked off and I think he said stock 51 jets. I wrote it down somewhere but don’t have access to my notes right now.

Thanks for all your comments!

[38 coupe]

I agree the compression is not the problem. The numbers look a little low to me, I am used to seeing 100 to 110 on a stock EAB, but I live near sea level which affects things a bit.


You may have fouled a plug while idling. I remember reading a while back that modern plugs lack glazing on the ceramic insulator, modern electronic fuel injected cars never flood out and foul plugs so the plug manufacturers reduced cost. Apparently if you foul a modern plug it can carbon track in the ceramic insulator and no amount of cleaning will get it to fire again. Let us know the outcome of the plug swap.

[jimvette59]

Not for nothing, check your oil if it's black you are flooding gas some how. JMO

[wga]

'New' Mallory condenser? Bubba set up a Mallory dual point for me, and I used the
new Mallory condenser. Stock 8BA in my 49 wagon. Less than 100 miles and it went south. Replaced with a Vertex and no problems for 12 years or more. At the same time changed to a Bosch blue coil, 12V internally resisted.
Regarding vapor lock, i added a spacer between the stock carb and stock intake. Cured that problem. Using a stock fuel pump, NGK B6L on stock heads.
Regarding running hot...how hot is H? Check head and thermostat housing temps with a temp gun.
With the electric fuel pump, what is your fuel pressure to the carbs? Is your regulator set up? Holly makes a nice regulator with a easy to read gauge.
Always been a fan of long roofs!

[Bruce_MO]

After reading all the content on plug lengths and aluminum heads, I realized I went down the wrong path with the shorter NGK plugs. I looked closely at the threaded holes in my Offy heads and was surprised at how far my plugs have been recessed all these years. Easily 3-4 threads in the head were exposed… yeah, maybe 1/4”. Bought longer plugs and spacers have been ordered. But I will also replace my new condenser with my old one and research a more dependable one. The Bosch coil is pretty new, so I’ll start with the condenser and do a few other suggested checks. I normally run my stock fuel pump and use my Airtex for priming. Only one other time have I had to use it for suspected vapor lock. It’s their low pressure unit… can’t recall the number. When driving home the other night, I tried it on and off and it made no difference. Car was running in “normal” temp range est. 180 (has 180 t-stats and just right of center on dash gauge shows 180 or so on my temp gun). So, assuming I don’t have a head gasket issue, I will chase down a bad condenser as a next step. I also have carb spacers and have done any number of other attempts to address hot restart issues. Always starts, but I haven’t floor it and crank for 7-10 sec to clear it out before it starts. If I restart it immediately after shutting off when hot, it’ll start in less than one revolution. If it sits for a minute or two, it’ll behave like it’s flooded.
Thanks for all the comments and ideas… much appreciated.