Spark gap- Gas vs LP

Roger in Iowa · Feb 24, 2013

Operators manual for 3020 says spark plug gap for gasoline is 0.025" but for LP is 0.015". Why?

Timing is more advanced for LP which I can understand because of higher octane.

gtx1967jewison · Feb 24, 2013

Lp engines have higher compression, higher cylinder pressure. This makes it harder for the spark to jump the gap. So you need less gap. OR nowadays the ignition has more voltage so you can have a larger gap AND high cylinder pressure.

buickanddeere · Feb 24, 2013

More non conductive molecules of air between the plug gap on a 8 to 1 compression engine than on a 6 to 1 compression engine.

Roger in Iowa · Feb 25, 2013

So will a different coil with higher output work better?

Where do you get such a coil?

David G · Feb 25, 2013

I would believe it would allow for a larger gap, thus should work better.

Lee B · Feb 25, 2013

From this site, Pertronix FlameThrower 12volt or 3 ohm would work fine without a resistor on a 12 volt system.

<a href="http://www.ytmag.com/40511_1502.htm">Pertronix oil filled 12 volt</a>

A bit pricey but worth every penny. There are other choices over there on the left side way up high.

gtx1967jewison · Feb 25, 2013

Yep. But then it burns points due to higher current. Thus the narrow gap solution. You'll need electronic ignition.

Spark gap- Gas vs LP

Roger in Iowa

Well-known Member

gtx1967jewison

Well-known Member

buickanddeere

Well-known Member

Roger in Iowa

Well-known Member

David G

Well-known Member

Lee B

Member

gtx1967jewison

Well-known Member

Similar threads