Spark plug question

[Plumpcars]

Hi all....I am a newcomer to the board and based in the UK. I have a '58 392 in a 34 Ford which is currently on the road and being enjoyed to the full. I have a question about spark plugs though. I read somewhere on the net that plugs should be run without gaskets as the tubes do the sealing. Is this correct? My plugs are fitted with gaskets and have never had any issues with oil or leakage but maybe I'm doing it wrong?
Am also interested to know what plugs people may be running?
Thanks.....

[DblAdigger]

Running gaskets on the plugs raises the heat range of the plugs. Don't run gaskets, Don't over torque the plugs.

[392heminut]

I've always run the gaskets on the plugs in my 392 and never had a problem. Back in the day the spark plug tubes were expendable items and were usually changed along with the spark plugs, and most were made out of aluminum so without gaskets they would wear out or crack at some point. Since the tubes aren't an on the shelf item and are expensive to boot, I choose to use the gaskets and save the wear and tear on my tubes. Also, whenever you change your plugs inspect the sealing area of the tube bottoms for cracks.I don't see how using the gaskets could raise the heat range of a plug and in 40 years of working on engines have never heard of that before! The heat range is designed and manufactured into the plug itself and can't really be altered!

[DblAdigger]

If you look at the heat flow diagram, from most all sparkplug manufacturers catalogs, you'll see that the heat is transfered from the plug base to the head/block. Lengthening that path, like with a gasket, will increase the distance the heat must travel. Ergo, higher heat range. Oh, BTW, I'll match your 40 years...and raise you 15.

[392heminut]

If you look at the heat flow diagram, from most all sparkplug manufacturers catalogs, you'll see that the heat is transfered from the plug base to the head/block. Lengthening that path, like with a gasket, will increase the distance the heat must travel. Ergo, higher heat range. Oh, BTW, I'll match your 40 years...and raise you 15.

You mean the gasket that the plug manufacturer designed the plug to be used with?

[DblAdigger]

Yup.

[phil]

im using champion nj12y in my 392 , i use them with the gasket , as when they tighten they squish the gasket down and seal on the tube , if you take the gasket off the plug will tend to tear the tube when tightening this has happened to me before ,
Can you post a photo of your 34 with the 392 , love to see it

[DblAdigger]

Phil, I think you have me confused with someone else, I haven't had a '34 for over 50 years. Now a AA/GD, that's only 40 years ago.

[Plumpcars]

Thanks for all of the answers so far, very much appreciated. Phil I will post a pic as soon as I work out how! New to the board so please bear with me...

[DblAdigger]

Had to look it up, for proof. 1957 Chrysler Service Manual, page 112, third paragraph, in BOLD print,"No (spark plug) gaskets are used on double rocker shaft engines". Hope this clears up my previous comment.

[Plumpcars]

Pictures as promised....

[392heminut]

Had to look it up, for proof. 1957 Chrysler Service Manual, page 112, third paragraph, in BOLD print,"No (spark plug) gaskets are used on double rocker shaft engines". Hope this clears up my previous comment.

I don't see any post here that disputed the fact that the factory recommended the use of the spark plug tube itself as the gasket. The issue is that that info is 51 years old and the tubes are no longer an off the shelf dealer item. therefore a lot of us don't care to use the plugs without the gaskets and take a chance on messing up the tubes that we have. If, as you say, using a gasket raises the heat range then go to the next step colder plug. Problem solved! I have been running Autolite 65's (the plug recommended for my 392) with gaskets for the last 7 years on the street and well over 100 passes down the dragstrip and have experienced no problems at all. I'm still using the same tubes I started with also.

[392heminut]

Plumpcars, that's a beautiful machine!

[mart]

Pictures as promised....

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Sweet car!!! Where/how the heck did you find a '34 Ford body and a 392 Chrysler engine
(and also all of the other parts required to build it ) in the U.K???!!! Is the body a U.S (or Canadian) built Ford or a British or German built version? Whatever it is, it is very cool
and must turn a lot of heads over there!!
mart

P.S. Are those Buick finned aluminum drums I see sticking out on the back side
of the front wheels???
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[scottm]

I love the hood notch to clear the HEMI...

[Plumpcars]

I hope the pictures didn't offend as I know it's a motor forum not a car forum! Thanks to all for your comments and guidance on the spark plug issue.
The car was originally put together by Johnny Best, a well known English rodder. It's an American style body but with a Ford commercial grille modified to fit. Has a push button torqueflite, 9'' rear and yes Buick's on the front. The motor is rare over here which tends to lead to a little voice in my head reminding me of that fact when my right foot is hard into it! Runs sweet as can be though and gives a huge grin factor. I would maybe like to go through the motor next year so am currently studying the Hotheads catalog for inspiration!