NO, do NOT remove the spark plug washers on drool tube heads!!

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TylerW

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So, I started noticing oil down the passenger side of my '68's engine. Nothing unusual there because there are 3 leak points...valve cover gasket, spark plug tube seals and steel shim head gasket. This engine no longer has the steel head gasket and the valve cover gasket isn't very old, so I got a set of tube seals and got busy.

I was concerned and curious why the spark plugs were only finger-tight, considering I replaced them a couple thousand miles ago. I examined the plugs closely and that's when I remembered that I had been brainwashed into removing the crush washer/sealing rings from the plugs due to the ridiculous information contained in this thread:

Remove the spark plug washers or not?

Before anyone helpfully posts "spark plug torque 30lbs try that it'll solve ur problem", I know that and have known it since 1990, thanks. They were torqued. The reason they loosened up was due to those missing crush rings. Do you guys actually understand what the function of those rings is?? Not only do they help seal the plug to the head(or tube in this case, they also help transfer heat and ALSO they help maintain torque on the plug when the washer crushes.

Just to make sure that I didn't miss something in the last 30 years, I checked several FSM's and they all call for the same plug....a Champion N14Y, WITH sealing rings. To further make sure I wasn't going soft, I read through all the TSB's I could find and I sure couldn't find one stating that Chrysler advocated taking washers off of non-tapered plugs.

Not only that, but there is some hooey contained in this thread regarding a "partial taper" in early heads. NO...ok? They call for the exact same plug as the later engines, period. I used my borescope to look at the sparkplug mating surface on my cylinder head and it is as flat as flat gets

To add even more to this train wreck, on another forum this same subject came up and some genius said to remove the washers on drool-tube and leave the on the plugs that go in later "peanut" heads. Are you crazy?? The later heads USE TAPERED PLUGS WITH NO WASHERS PROVIDED OR NEEDED.

Back on the original thread up top, someone also said to make sure the tubes weren't chewed up at the bottom from "someone not removing the washers". That's not a lockwasher with a raised end, genius. It's a perfectly smooth washer that would have to be removed and reinstalled many times before it would cause significant wear.

I think the genesis of the idea to take the washers off was to get the plug in further and allegedly improve combustion and power by .00001% of 1 horsepower. These are 100hp engines with low compression...not an alcohol-burning funny car. I have the FSM's for each car I own and I maintain them by the book and never have problems...until I tried something like this. Leave the washers on the plugs.
 
Uncle tony said on a recent video to remove the washer. I always left them on, never was an issue.
 
Tyler, there's nothing wrong with guessing and assuming based on what you think you understand. The problem comes when you get on the internet and holler your guesses and assumptions in BIG LOUD ALL CAPS, and gloat about how right you are and how wrong and stupid everyone else is, and how thorough a job you did checking Chrysler's publications.

See here for the correct info as published by Chrysler in TSBs that are not difficult to find.

Yes, the Champion N14Y came with a washer, which was used in some of the many other applications for this spark plug. Here's a page from the 1970 Dodge FSM. The same language is in the '63, '64, '65, '66, '67, '68, '69, '71, '72, '73, and '74 FSMs, and that's the whole year range of \6 heads for which the plugs are to be installed without ring washers.

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Thought that was common /6 knowledge....well its even more common now. Flat seat socket, flat seat plugs, soft AL plug tubes between. Now @slantsixdan educate us on the Chrome alloy cast iron they used to make the cylinder head!
 
And it's right on the mark, too. If you remove the plug tube, you can see the counter bore around the plug hole the end of the plug tube fits into. I just recently saw this on the head I rebuilt for the new engine in Vixen. The head is a 65 model.
 
So, I started noticing oil down the passenger side of my '68's engine. Nothing unusual there because there are 3 leak points...valve cover gasket, spark plug tube seals and steel shim head gasket. This engine no longer has the steel head gasket and the valve cover gasket isn't very old, so I got a set of tube seals and got busy.

I was concerned and curious why the spark plugs were only finger-tight, considering I replaced them a couple thousand miles ago. I examined the plugs closely and that's when I remembered that I had been brainwashed into removing the crush washer/sealing rings from the plugs due to the ridiculous information contained in this thread:

Remove the spark plug washers or not?

Before anyone helpfully posts "spark plug torque 30lbs try that it'll solve ur problem", I know that and have known it since 1990, thanks. They were torqued. The reason they loosened up was due to those missing crush rings. Do you guys actually understand what the function of those rings is?? Not only do they help seal the plug to the head(or tube in this case, they also help transfer heat and ALSO they help maintain torque on the plug when the washer crushes.

Just to make sure that I didn't miss something in the last 30 years, I checked several FSM's and they all call for the same plug....a Champion N14Y, WITH sealing rings. To further make sure I wasn't going soft, I read through all the TSB's I could find and I sure couldn't find one stating that Chrysler advocated taking washers off of non-tapered plugs.

Not only that, but there is some hooey contained in this thread regarding a "partial taper" in early heads. NO...ok? They call for the exact same plug as the later engines, period. I used my borescope to look at the sparkplug mating surface on my cylinder head and it is as flat as flat gets

To add even more to this train wreck, on another forum this same subject came up and some genius said to remove the washers on drool-tube and leave the on the plugs that go in later "peanut" heads. Are you crazy?? The later heads USE TAPERED PLUGS WITH NO WASHERS PROVIDED OR NEEDED.

Back on the original thread up top, someone also said to make sure the tubes weren't chewed up at the bottom from "someone not removing the washers". That's not a lockwasher with a raised end, genius. It's a perfectly smooth washer that would have to be removed and reinstalled many times before it would cause significant wear.

I think the genesis of the idea to take the washers off was to get the plug in further and allegedly improve combustion and power by .00001% of 1 horsepower. These are 100hp engines with low compression...not an alcohol-burning funny car. I have the FSM's for each car I own and I maintain them by the book and never have problems...until I tried something like this. Leave the washers on the plugs.

I quit reading about halfway thru this post , I ran w/o the plug washers in my hemi for 14 yrs with no problems , nary a one !
Even got the idea from Tom Hoover ! The alum tubes sealed very well , unless they are worn out or chewed up from the washers to start with .
 
Hey Dan, I just installed the NGK ZFR5n's in my 74 Slant. I removed the gaskets, but I noticed the base of the plugs was more narrow. Does that counterbore stop the more narrow plug? I ask because the plugs tightened to about 20 ft lbs. and then loosened up almost like they were stripping ( or breaking through the tube) but then tightened up properly. What do you guys think
 
HI just installed the NGK ZFR5n's in my 74 Slant. I removed the gaskets, but I noticed the base of the plugs was more narrow. Does that counterbore stop the more narrow plug?

Yes; the only practical difference is the hex size (what size socket you need to remove/install).

the plugs tightened to about 20 ft lbs. and then loosened up almost like they were stripping ( or breaking through the tube) but then tightened up properly
That was the plug pushing a ridge of carbon out the lower end of the plug threads. It's fine; don't fret.
 
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