Did the rebuild include hardened valve seats, needed to use unleaded continuously?

WW2 "pool petroleum" for vehicles was much lower octane than current fuels so I'd have though ordinary unleaded was more than adequate.

I have a 1943 Wiilys Jeep MB with an original Willys Go-Devil engine. Last October the engine was re-built and fitted with new pistons, new valve seats, and new valve guides.

Is it better to use normal unleaded with Lucas lead replacement additive, super unleaded with the additive, super unleaded by itself, or what?

I seem to be getting a lot of contradictory advice from friends!

Unless you are going to be driving it at high speeds for long periods of time normal unleaded should be fine. In other words long motorway journeys are a no no. I do however use Castrol Valvemaster which is one of the top recommended additives when refueling my pre-war cars which are only used on A and B roads as some sort of extra precaution. I am not convinced that it gives adequate protection when used in anger as the B Series engine in one of my cars suffered from valve seat resession after only 4500 miles of fairly hard driving on long runs. I have now had the the cylinder head properly converted for the use of unleaded fuel and have reached the conclusion that this is the only satisfactory solution.

Edited by Wolfan on 18/05/2016 at 20:51