Spark Plug Leak On 1 And 4... :(

So I put plugs (and other stuff) on the Heep yesterday. Discovered some oddities.

The plugs that were in it were Autolite 26s. The place I bought my ignition stuff from sent me Autolite 295s. The threads and the depth are the same, but the 295s seal with a crush washer instead of a tapered shoulder like the 26s do.

Anyway, I swapped out my plugs, and found that cylinders 1 and 4 had some kind of odd extension on the plug....



Never seen something like that before, heh. They are seized on good, and I can't get them off the plugs...

Anyway, I put in the 295s (after cleaning up around where they go), torqued them good, and fired up the machine. Then saw some bubbles in the residual PB Blaster from removing the old plugs. Sprayed a little more down in there to see, and discovered that I have leakage around the plugs on cylinders 1 and 4.

I figured, it can't be coincidental that the old plugs had those weird things on the two cylinders that leaked. But on a lark, thinking maybe I just was sent the wrong plugs, I installed the old plugs from 2 & 3 (without the weird thing on them) in 1 & 4, and that seemed to fix the leak. They are garbage and all fouled, and miss a lot though, so I put the new plugs back in.

Anyway, what do y'all think is going on here? I don't see any cracks, and the face that the crush washers should be crushing on is smooth, but they still leak on those two cylinders... Was I sent the wrong plugs? Or is this just an "F-134" thing that I ought not worry about, since it seems to be running ok (aside from a miss at idle, which I am thinking is a clogged idle jet in the carb rather than an ignition thing).

 

Anti-foulers, to help burn excessive oil off the electrodes.

A Dorman part, they are offered with gasket seats, or with taper, for different engines.

Amazon.com: Dorman 42009 Spark Plug Non-Fouler - 18mm Gasket Seat, Pack of 2: Automotive

 

You can see that the tapered part is contacting the flat seat in the head on a single line. If the proper plug with a crush washer does not seal, I would get down in the cylinder head and scrape any carbon or other debris from the flat seat. It should seal with the proper plug ...

You can buy the non-foulers from Dorman - Dorman Products - Search Results - any parts store can get Dorman stuff within a day or two. These parts pull the plug electrode back from the combustion chamber and reduce oil fouling. Typically these are used on badly worn engines that are burning a lot of oil - they are a stopgap to get a few more miles out of an engine that needs rebuilding.

 

You notice that two of the plugs do not go in as far as the others to seat?

 

Agreed anti foulers by moving the plug up out of the combustion chamber it helps (a tiny tiny bit) to stop oil from fouling the plug. You can also put a little bit of anti seize on the plug threads to help seal them. I just paint the stuff round a couple of the middle threads on the plug.

 

Hmm, I thought I had cleaned out down in there pretty good, but I'll try scraping more aggressively.....

This engine supposedly only has 10,000 miles on it. I wonder if I was lied to, or what..... It doesn't seem to burn any oil that I can tell, though it does smoke a bit when I first start it.

I also wonder if the taper plugs that were in it were torqued too tight, and made a burr around the seating area that's messing up the crush washer seal.... Hmm yes, this bears further investigation. Tomorrow. Though I didn't feel anything unusual down around the hole when I was cleaning them up...

 

Those anti-fouling devices grew in popularity in the early 1970's when Chevy Vegas scored their aluminum cylinder walls and started heavily burning oil. Back in the day, the dealer installed them on my old Vega.
-Donny

 

Never used them in my '74 Vega. I did use a set of 8 in my '66 Olds Dynamic 88, though. I put over 300K on that engine!