Petrol

[French Tickler]

Hi, I have a 1954 H van, with a traction engine, will this need a fuel additive, or will the valve seats be OK with normal unleaded?

[addo]

The traction engines I've seen here, ran best on coal.

Nah, more sirriously, I would use an additive or scare up an NOS head gasket and get hardened seats installed. Out of perversity I'd probably lightly clean up the bowls and ports while in there.

[lexi]

It depends how much lead memory is left in your seats. If it has been run for years with unleaded then there will be some/much valve recession. I ran a 1961 Land Rover for about 4 yrs with a non leaded head. I put a splash of additive in now and again.
I bet your engine doesn't work quite as well as factory intended with this crap Ethanol unleaded fuel.