Should I try Hotter Plugs?

Bob's '31 Cab

Bob's '31 Cab

Junior Member
I've just recently installed a newly rebuilt engine with 5.5 / 1 C.R. head & larger intake & exhaust valves.

I installed the same plugs i was using previously which are Champion W16Y (always alittle sooty) in my stock engine.

I've gapped the pts. to .020 and timing is right on, and the carburator's float level has been set accordingly, and seems to have a strong spark.

When running, the engine seems as though it is missing some what and lacking power. After pulling the plugs I've found a good amount of soot around the plugs.

My question for the experts are, should I think about using a hotter plug?
and if so what would you suggest? or anything else I should try :confused:

As always, Thanks in Advance for your reply's

Bob Galli
 
Bob,I have a Snyder's 5.5-1 head and after experimenting with different plugs I have found the Champion W18's by far run the best.NO SOOT and a nice grayish color at the electrode.They have been in the engine for 4yrs now with 15,000 miles and still work perfect.I also run a 160 degree thermostat to keep the temperature in range.
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I think you are jumping the gun here. Higher compression generally requires a colder, not hotter plug. You say the W16Y's were a little sooty previously, and now with a rebuild with slightly higher C.R. and bigger valves you have the same problem? Are you using the same coil, dizzy, carb? Sounds like you had a problem before, and you transfered it to the rebuild. I'd check the following in this order: weak coil or spark; ignition timing; manifold gasket leak; carb jetted too rich; cam to crank gear timing. Even if the plugs were way too cold, if starting with clean plugs everything should run OK for a short while until they accumulate excessive unburned carbon on the porcelain insulator causing them to misfire.
 
i agree , clean your plugs & see . if i were to go up (hotter) i too would chose w18 .
good luck ............... steve
 
I agree with Mike. Your problem is a pre-existing one from some source other than the head. Many carburetors out there are too rich. What type of mileage are you getting?
 
Champion W-16 Y, 0.035 gap. As close to 3-X [1,300 deg F.] as you'll come.
I luv 'em!

I found I was running a wee bit rich, closed down the mixture adjustment screw to about fully closed. Just a tad open. Unless I'll pulling a hill. Then I retard a little and rich'en up. Next manouver will be an landing...LOL


skip.
 
Champion 3Xs always work for me. I know they're expensive, but they work good and look great. They also come apart for cleaning so you should never have to buy sparkplugs again. I'm running 80 year old originals that work just fine.
 
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