How much Marvel Mystery Oil per tank?

[1930-Pickup]

Originally Posted by Crankster

For upper cylinder lubrication and valves, valve guides etc, engine vacuum was used with "inverse oilers" like the Ampco unit here, Marvel made them as well. A small metered dose is mixed in with the fuel/air charge. Ampco pointed out that adding Marvel oil to the fuel may dissolve sludge or varnish in the tank and this was a better way.

http://ampcolubes.com/home/benefits

Years ago I put a NOS Ampco system on one of my vintage cars. Setting the feed rate was a massive pain in the a#*. It also had a weird feature: the MMO would actually migrate THROUGH the wall of the glass reservoir and so it was always oily. Too strange!