ORIGINAL: FNQFLYER
Senior Telemaster, re you converting the FG14 to methanol, I made mention elsewhere about some tests Brian Winch did with an FG20 and glo plugs ec. The article about it is in the latest editio of our Oz magazine Airborne.
Re the YS leaks, given the tank pressure developed of in excess of 10psi some blow by leakage of the check valve was considered acceptable. The early 53's had no leakage and what that system did to a plastic tank was very interesting and usually expensive. I used metal tanks in all my YS installations and had no problems.
Old fart another approach to your tank problems is presseure (even muffler) on the main tank and feed the fuel to the engine via a small (20z) header tank. Oldie but a goodie.
FG84 is the gas version of the FA450R3D radial.
I WOULD NEVER convert any engine to glow ignition. It is just so unreliable compared tp CDI. (Capactive Doscharge Ignition)
If I were to convert an FG84 to methanol it would involve swapping a 13mm glow fuel carburator, advancing the ignition timing & increasing the compression ratio.
An 84cc radial W/a healthy CR running on nitro/methanol W/CDI should make about 7-8HP. Quite a bit more than the specified 5.8HP on gasoline.