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Spark plug education

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tundrarules

Regular Contributor
Fast Jeff mentioned that a overtight spark plug my cause a cylinder to run hot...so I started reading up on spark plugs.

The 318 engines in my Marinette are angled which caused the front cylinders to run lean and the back cylinders to run rich. The manual spec plug for the Chrysler 318 is the Champion RN9Y with a .032 gap.

95% of the time my engines stay below 2000 rpms :)

Question of the day?? Do I need to run hotter plugs in the back 4 cylinders or maybe all cylinders?

What gap should I use with my 45,000 volt coils?

http://en.wikipedia.org/wiki/Spark_plug

http://www.ngksparkplugs.com/techinfo/spark_plugs/installation.asp

The 318 engines in my Marinette are angled which caused the front cylinders to run lean and the back cylinders to run rich. The manual spec plugs are Champion
http://www.federalmogul.com/en/Afte...Products/ChampionSparkPlugs/PowersportMarine/

http://www.championsparkplugs.com/sparkplug411.asp
 
All the rear cylinders of angled engines will be fouled from what I read. Fuel fouled black sooty rich on all rear cylinders.

Like I said, most of the time my engines are at idle or below 2000 rpm. Seems a good habit is to run for 5 min or so at high idle before you get to the marina. This should blow off fouling and remove moisture build up within the engine.

Do you guys with the older tilted engines (1986 or before) have rich rear burning cylinders and lean front burning cylinders? Any tips? :confused::confused::confused:
 
Is the 318 2bbl carb or 4bbl carb? If your never up on plane the fuel will be running toward the rear. Never ever run different types of plugs all must be the same. One cylinder will run hotter then the other and can cause ring and piston issue. Plugs should be a nice tan to light brown in color. too white and running lean and too dark to black and running rich.
 
tundrarules said:
All the rear cylinders of angled engines will be fouled from what I read. Fuel fouled black sooty rich on all rear cylinders.

Like I said, most of the time my engines are at idle or below 2000 rpm. Seems a good habit is to run for 5 min or so at high idle before you get to the marina. This should blow off fouling and remove moisture build up within the engine.

Do you guys with the older tilted engines (1986 or before) have rich rear burning cylinders and lean front burning cylinders? Any tips? :confused::confused::confused:
Click to expand...

My 1963 dual quad 426 is very tilted and it has no issues with plugs. Remember the intake manifold is under a vacuum.
 

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No need to put different plugs in the low/ back side. (If you're fouling them at idle you have carb issues to correct.)

Use the same plug gap as usual (0.035 ?)


Jeff

Fastjeff Spark Plug Rule Number One: Colder than needed plugs can foul at prolonged low speed running. Hotter than needed plugs cause preignition, which causes holes in pistons.

Take your pick.
 
I have a M47 crown in my Gar Wood. I have never had any sort of flooding issue. The new gas and a cast iron carb is a big PITA.
 
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