The Ford Barn

cuzncletus · 06-13-2012, 12:37 PM

Does indexing plugs help much with flathead performance? If so, which direction should the electrode go?

Mark Slight · 06-13-2012, 01:25 PM

Spark plug - Wikipedia, the free encyclopedia

... it can go up ... of the end of the electrode ... that the open area of the spark gap, not shrouded by the ground electrode, faces the center of the combustion chamber, towards ...
en.wikipedia.org/wiki/Spark_plug - Cached - More from this site

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More accurate than I could do, give this a read. :-)

Mark

B-O-B · 06-13-2012, 07:59 PM

I mentioned this @ one time & was told it is a waste of time & not necessary. Can't recall who told me that or if it was on this site or another.

3quarter32 · 06-13-2012, 08:34 PM

We tried indexing on motorcycles using a dyno. Never really could tell any difference one way or the other. Unless your running a AA dragcar, where hundredths of seconds count, doubt that it would help anything.
Lee

JWL · 06-13-2012, 09:47 PM

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Plug indexing originated to help solve clearance issues.

To better expose the sparks, in a Flathead, the ground electrode should be placed, approximately, on the intake manifold side of the chamber. I have done dozens of tests with the plugs indexed in every concievable position without being able to demonstrate a difference in performance at wide open throttle settings.

06-13-2012, 12:37 PM	#1
cuzncletus Senior Member Join Date: Aug 2010 Location: Sevierville, Tenn. Posts: 391	indexing plugs Does indexing plugs help much with flathead performance? If so, which direction should the electrode go?

06-13-2012, 01:25 PM	#2
Mark Slight Senior Member Join Date: May 2010 Location: Dixon, CA Posts: 473	Re: indexing plugs Spark plug - Wikipedia, the free encyclopedia History \| Operation \| Spark plug construction \| Heat range ... it can go up ... of the end of the electrode ... that the open area of the spark gap, not shrouded by the ground electrode, faces the center of the combustion chamber, towards ... en.wikipedia.org/wiki/Spark_plug - Cached - More from this site More results from en.wikipedia.org » More accurate than I could do, give this a read. :-) Mark Last edited by Mark Slight; 06-13-2012 at 02:00 PM.

06-13-2012, 07:59 PM	#3
B-O-B Senior Member Join Date: May 2010 Location: Ft Mohave,Az Posts: 1,987	Re: indexing plugs I mentioned this @ one time & was told it is a waste of time & not necessary. Can't recall who told me that or if it was on this site or another.

06-13-2012, 08:34 PM	#4
3quarter32 Senior Member Join Date: Feb 2012 Location: Broken Arrow, OK Posts: 147	Re: indexing plugs We tried indexing on motorcycles using a dyno. Never really could tell any difference one way or the other. Unless your running a AA dragcar, where hundredths of seconds count, doubt that it would help anything. Lee

06-13-2012, 09:47 PM	#5
JWL Member Emeritus Join Date: May 2010 Location: Fitzgerald, Georgia Posts: 2,204	Re: indexing plugs Sponsored Links (Register now to hide all advertisements) Plug indexing originated to help solve clearance issues. To better expose the sparks, in a Flathead, the ground electrode should be placed, approximately, on the intake manifold side of the chamber. I have done dozens of tests with the plugs indexed in every concievable position without being able to demonstrate a difference in performance at wide open throttle settings.