I recently gave the car a tune-up and found out the following:
Old spark plug gapping: @ .072 New spark plug gapping: @ .054
Under the hood there is a label which states that the range should be between .052 - .056
I bought bosch platinum spark plugs and the gapping was: @ .062
what should I go by? How much does this affect the engine? Would this keep the engine from not idling properly?
I'll let others answer the technical aspects but I'm curious why you wouldn't follow Ford's spec. I wouldn't think the gap set at the Bosch plant has any relevence to a specific application.
Richard
>
A larger spark gap requires more energy to make a good spark. Too big of a gap will decrease efficiency, decrease fuel mileage, and increase emissions. Just set it to factory specs and don't worry about it.
I'm curious why you would buy Bosch..
If you paid attention on here and alt.autos.ford, you would know that Bosch Plats didnt run good in ford distributor cars. Single plat application, obviously. For ME that is enough to rule them out, FOREVER - even in DIS cars, as people never seem to have trouble with the designated Motorcraft plugs, anyway.
The classic symptom of Bosch Plat in Ford is random miss at idle speed and at cruise. Watch for it.
I agree go with the motorcraft double platinum plugs. plat tip and electrode. set at factory specs and you may want to change plug wires while your at it. the silicon wire will look good forever but do start to breakdown internally at around 100k to 110 k miles
Reply to message from Backyard Mechanic (Thu, 18 May
2006 04:40:48) about "Re: Idling problem":
Ummm. I'm fairly new to this group and use bosch plat singles in my '75 II. What is this about them being bad? (hate re-stir things up)
Schadenfreudist Fri, 19 May 2006 20:06:23 -0700
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Sorry... should have qualified that to TFI equipped... I have no idea on Duraspark or points cars. SEE above... appears in a couple thousand miles. But, AGAIN, Motorcraft makes great plugs.
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