I am experiencing frequent “popping” sounds on my ‘30 A the same as described in Mr. Chauvin’s response to another earlier inquiry as shown below: My timing checks OK.
My questions are:
1. I presume that Marvel Mystery Oil would be preferable to Liquid Wrench?
2. How much Marvel Mystery Oil should be added to each spark plug hole”?
3. Do I rotate the pistons to then force the MMO to the valves head area?
Thank you in advance.
George
Originally Posted by H. L. Chauvin
Hi diy,
From miles away, and not being able to see or hear your "popping", this sounds like this could be a typical Model A that did not run for extended periods in a long time.
If so, with this possible condition, the volatile components of the oil lubrication at the valve stems & valve guides evaporated and left a sticky varnish material such that the valves are sticking, & moving up and down slowly; hence valves could be out of time causing delayed combustion "outside" of combustion chambers which one can readily hear & sounds like "popping".
As stated, (again if this is the case), moving the spark lever up & down changes ignition timing slightly, affecting engine "popping"; however, ignition timing changes are not enough to correct delayed valve timing, "and popping".
This "popping" caused by sticky valves was as common as a common cold in our area where old vintage tractors were not used in off-season-periods ...... sounded like a 12 gauge dove hunt in a farmer's back yard.
Before Liquid Wrench, Marvel Oil, & other "Mechanics in a Can", we all soaked our valves for 24 hours with Kerosene poured in each spark plug hole ....... this was the vintage miracle cure that worked 100% of the time to dissolve the varnish, set the valves free, and made our neighbors quit staring at our "popping" war zone.
But remember, ............. just one possibility.
My questions are:
1. I presume that Marvel Mystery Oil would be preferable to Liquid Wrench?
2. How much Marvel Mystery Oil should be added to each spark plug hole”?
3. Do I rotate the pistons to then force the MMO to the valves head area?
Thank you in advance.
George
Originally Posted by H. L. Chauvin
Hi diy,
From miles away, and not being able to see or hear your "popping", this sounds like this could be a typical Model A that did not run for extended periods in a long time.
If so, with this possible condition, the volatile components of the oil lubrication at the valve stems & valve guides evaporated and left a sticky varnish material such that the valves are sticking, & moving up and down slowly; hence valves could be out of time causing delayed combustion "outside" of combustion chambers which one can readily hear & sounds like "popping".
As stated, (again if this is the case), moving the spark lever up & down changes ignition timing slightly, affecting engine "popping"; however, ignition timing changes are not enough to correct delayed valve timing, "and popping".
This "popping" caused by sticky valves was as common as a common cold in our area where old vintage tractors were not used in off-season-periods ...... sounded like a 12 gauge dove hunt in a farmer's back yard.
Before Liquid Wrench, Marvel Oil, & other "Mechanics in a Can", we all soaked our valves for 24 hours with Kerosene poured in each spark plug hole ....... this was the vintage miracle cure that worked 100% of the time to dissolve the varnish, set the valves free, and made our neighbors quit staring at our "popping" war zone.
But remember, ............. just one possibility.
