Quote:
Originally Posted by Dave Page
I have no idea how many times I have heard the -must harden your valve seat talk - because there isn't any lead in the fuel. For engines of WW2 vintage this is not true for several reasons. First, engines of our period were developed to run without lead, Tetraethyl lead was added during the war to -boost- the octane level (more on that later) this was done to reduce engine knock/pre-ignition.
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Dave,
You may not be aware, but quite number of military vehicles built during WW2 were fitted from new with hardened valve seats, to give a few examples, Dodge WC models, Austin K5 and K6, Morris Commercial four cyl engines, etc. so nothing wrong in fitting them now. If a valve seat is recut too many times it pockets, then the exhaust valve suffers burning as the hot gasses cannot freely escape. By fitting hardened seat on overhaul, it is a fit and forget operation as with the low use most of these vehicles have it will reduce the times a head is lifted to attend to burnt seats.