Submerged Hemi spark plugs

[Thunderlugs]

I decided to treat my Hemi Coronet to some fresh Plugs after a few years and a couple hundred miles, since I detected a occasional miss while driving it recently. I found 2 of the plugs submerged in oil up to the plug boot inside the tube. How in the hell is that oil invading the tube? ...I must say, I am a little stumped . Anyone else experience this ? Heads are 67 castings with no special seals installed at the base of the tubes. Thanks.

 

[Zeppelin264]

Isnt there seals on the bottom side of the valve covers for the spark plug tubes?

Never owned a Hemi, but Hondas are like this. Same design.

 

[POMONAMISSEL]

well there is only one seal at the top of the cover stock . but none on the bottom , just the spark plug washer and its not a great oit stop . on my early hemis we cut a seal grove in the heads for the spark plug tubes and use better seals as well . hope you get it fixed , thats a cool ride .

 

[Thunderlugs]

Isnt there seals on the bottom side of the valve covers for the spark plug tubes?

Never owned a Hemi, but Hondas are like this. Same design.

yes there are O rings that seal the tubes on top. My problem has to be at the base of the tube where the plug screws into the head.

 

[65hemi]

My Stage V heads have an o-ring in the head to seal the bottom of the tube.
For stock heads, you can get seals like these from Mancini to better control the oil near the plug tube.
http://www.manciniracing.com/mihehetuseki.html
There are other similar products available. I got a set from a guy on ebay.

 

[snakeoil24]

Buy yourself a set of press in aluminum foot seals, remove the washer and replace the upper O rings. If the uppers push in too easy they asre cooked.

 

[chooch]

Mine does the same on a couple tubes & i even have the milodon seal inserts in the heads just nature of the beast. Check the bottom of your tubes to make sure there not cracked & get rid of the spark plug washers.

 

[64BEL]

I remove the washers, but mine still come out with oil all over the threads. Better than with the washers on, though.

 

[snakeoil24]

Crazy set up the only otyher thing to reduce the oil is measure the lenght of the tubes ansee if they are all same lenght. The o ring intot he spark socket needs toseat enough. Also are the tubes out of round from dropping or flattened on once side.

 

[snakeoil24]

These inserts are on ebay for 75.00

 

[HEMI-ITIS]

I also have the Miodon bottom seal and still get some oil in there.Gotta pull the plugs REAL fast to read them!

 

[Thunderlugs]

I remove the washers, but mine still come out with oil all over the threads. Better than with the washers on, though.

Thanks I will start with removing the washers. Hope to see you at Dodge City on Friday!

 

[not so famous bob]

I also have the Miodon bottom seal and still get some oil in there.Gotta pull the plugs REAL fast to read them!

View attachment 501472

I had them on my racecar also, they didn`t work worth a flip. if u got good tubes, or new ones, don`t use washers on ur plugs. that`ll help for a while. we ended up just putting up w/ it. (14 YRS.) didn`t have any miss fire tho.

 

[Thunderlugs]

I had them on my racecar also, they didn`t work worth a flip. if u got good tubes, or new ones, don`t use washers on ur plugs. that`ll help for a while. we ended up just putting up w/ it. (14 YRS.) didn`t have any miss fire tho.

I should say I found a carbon track on #3 plug causing the likely misfire.

 

[64BEL]

Thanks I will start with removing the washers. Hope to see you at Dodge City on Friday!

Me too - I want to see your Coronet!

 

[mopar 3 B]

Just be glad it is not a 99 2.5 v6 that fries a diode in the distributor every time a tube fills with oil and it is never a front plug.

 

[Bigal75]

Yes. I have the orings and they still leak a little. Nature of the beast.