8n ford with 115 lb compression on #1 cy fouls plug

old diesel · May 25, 2015

new to me 8n ford run ok but is fouling #1 plug- it has 115 lbs compression. the other 3 cyls have about 120lbs and burn clean. hear one value click (loud). could #1 values be out of adjustment enough to cause fouling of plug. can not make out serial #, but it has front dist. and old styled steering sector. thanks ahead for any help

WW2N · May 25, 2015

Could be a lot of things- Are you getting good white spark that will jump 1/4
in. Use 437 Autolite plugs Check your spark is 1st step. With 120 115 readings
you got a darn good engine.

Bob · May 25, 2015

Likely, something has happened to the oil control ring. Upper rings hold compression, lower ring scrapes oil off of cylinder wall and returns it to the crankcase.

So compression close to the other cylinders doesn't mean there is oil control.

Dell (WA) · May 25, 2015

OD.........would it surprize you to learn yer "fouled" sparkie is probably ignition wire associated ...NOT... compression associated. Me? I'd gitta NEW set of COPPER cored sparkie wire and cut to length. DO NOT USE modern "string" core sparkie wires. ........Dell, yer self-appointed sparkie-meister

Hobo,NC · May 25, 2015

(quoted from post at 02:09:57 05/26/15) new to me 8n ford run ok but is fouling #1 plug- it has 115 lbs compression. the other 3 cyls have about 120lbs and burn clean. hear one value click (loud). could #1 values be out of adjustment enough to cause fouling of plug. can not make out serial #, but it has front dist. and old styled steering sector. thanks ahead for any help

The plug is talking to ya..

http://ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp

kylemorley · May 26, 2015

my 8n had great compression according to the gauge, even when oil was making it by the rings in such quantity that if the engine didn't
start on the first bump the plugs would be covered with oil and nothing less than washing them in gas and blowing them dry would get it
to start again.

Seemed odd this could happen with such good compression, but apparently compression and oil control are two different jobs done by
two different parts - compression and oil rings - and one can be bad but not the other. Best I can figure, the excessive amounts of oil in
the cylinders was actually running up the compression, the way it does when you shoot the oil in during a compression test.

I was fortunate in that the oil rings seemed to be stuck rather than worn out, and several MMO soaks got them working again to the point
where the plugs no longer foul and the engine starts instantly and doesn't smoke. What is the compression now? Don't know - it's
working now so why push my luck?

8n ford with 115 lb compression on #1 cy fouls plug

old diesel

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WW2N

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Bob

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Dell (WA)

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Hobo,NC

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kylemorley

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