Indexing Spark Plugs
 

Does anyone know of indexing washer availability for the standard 3x size plugs, or has anyone ever messed with them in regards to the model a? It would seem that detonation reduction and better flame travel could be possible by putting the ground electrode at the back of the chamber. Just curious. I always did it on a Lingenfelter corvette i had built by them years ago per their instructions, and just watched a you-tube video with a small brigs and stratton flat head odor with a plexiglass head, running with a ultra high speed camera. they weren't indexing the plugs in the video, but it sure seems like the flame travel and detonation reduction could be improved by having the group electrode indexed.... Thoughts?

Re: Indexing Spark Plugs
 

No matter what I have tried I haven't been able to get pinging/ detonation out of a properly restored stock engine--- I even tried old gas that made the lawnmower knock under load, --- full spark advance, full throttle from 5 mph in 3rd going up the steepest hill around-- this is with 3X plugs---
When I had a worn cam and the valves were sunk from many valve grinds then I could get it sometimes with bad gas

Re: Indexing Spark Plugs
 

I seriously doubt you will see any gain or loss as the plug is not projected into the combustion chamber like a more modern style engine is.
Smokey Yunick invented the Projected core spark plug back when he was working with Champion.

Re: Indexing Spark Plugs
 

Mark,

Good question, especially since you had the Lingenfelter Vette experience.

In my opinion, it is wasted effort in the Model A motor. The technology advances made in the last 60 or 70 years have proven that the original designs were not the most efficient.
The latest design combustion chambers has shown substantial increases in power and one factor is the placement of the spark plug along with C/R and chamber shape.

John

Re: Indexing Spark Plugs
 

How would the placement of the spark plug work out with the lion head ?

Re: Indexing Spark Plugs
 

Maybe i should clarify... Not looking for more horsepower. Running a Stock rebuild, rebuilt Zenith with flowed jets, and replaced bushings, and a rebuilt stock distributor. have NO audible detonation. runs great... But I have ran my car with a 12 volt battery in the back seat hooked to a wideband bosch O2 sensor bolted to the exhaust tailpipe, and do know that a well running, properly timed, motor has because of fixed timing (well hand controlled) has extreme air to fuel ratio swings, based on load, rpm, and overall advance. air to fuel ratio at idle would range from 9 to 16.5 base on timing. and at bout 2200 rpm or 50 ish cruising, would move from 12 to 20 base on throttle. Happily under full load, floored at about 4 clicks up from full advance i ran rich, at about 11 to 12. Rather burn extra fuel than ring gaps.
But, for $10 in indexing washer (if available) and a little time, id be up for a little better effency/flame travel.... was amazed after seeing the video of a flat head chamber running in slow motion.... also was referring to a stock/stock type chamber (brumfield, C, snyders 5.5 or 6.0). not a center piston plug lion or ohv set up, understandably those would be different.

Re: Indexing Spark Plugs
 

Since you are dealing with a flat surface under the plug base, I would try McMaster Carr. Listed under "Low Carbon Steel Round Shims", are a variety of ID dimensions and thickness of .0005 and up. Stack them up and get the electrode where you want it.

Re: Indexing Spark Plugs
 

Indexing spark plugs is about as useless as trying to milk a butterfly.
Bill Abnoxious

Re: Indexing Spark Plugs
 

Bill, you might get buttermilk.

Re: Indexing Spark Plugs
 

Is this April fool's day??:rolleyes:

Re: Indexing Spark Plugs
 

I'm ticked off, my grocery delivery shorted my BUTTERMILK today:mad:
I have a bottle of "FIREFLY" Lamp fuel, "wunder" how many LIGHTNIN' Bugs they had to "milk"????---As difficult as checkin' the BALLS, on a MOTH:eek::eek: (Hold STILL!)--LOL
Bill Goofy

Re: Indexing Spark Plugs
 

Add 1 tablespoon of vinegar or lemon juice to 1 cup of whole milk to make a substitute, wait 5 minutes. Good when making ranch dressing or buttermilk pancakes/biscuits etc. The latter needs the acidity that buttermilk provides to react with the baking powder. And that gives ya fluffy pancakes and biscuits, jus' like Grandma made!

Re: Indexing Spark Plugs
 

YO' Crankster,,
Another COOK in the crowd, WELCOME, BROTHER!
Bill W.