If leaded gas was ever burned in a Jet engine, it would eat up any titanium in the engine. Lead, heat and titanium do not get along very well. I discovered that the hard way. As a young airman I used a lead pencil to mark a loose rivet on the tail cone of a F-102A. After flight there was a large hole on the tail cone where I had used the pencil. I thought my supervisor was going to kill me.
Berny
Phormer Phantom Phixer
On the bench
TF-102A Delta Dagger, 32nd FIS, 54-1370, 1/48 scale. Monogram Pro Modeler with C&H conversion.
Revell F-4E Phantom II 33rd TFW, 58th TFS, 69-260, 1/32 scale.
Tamiya F-4D Phantom II, 13th TFS, 66-8711, 1/32 scale. F-4 Phantom Group Build.