[Mgs] Unleaded fuel and Cylinder Head

[Barney Gaylord]

At 04:08 PM 2/21/2009 -0800, Tom Buchanan wrote:
>I know this has come up many times but not when I'm doing my heads. 
>The '65 head goes to the machine shop next week. I need to know what 
>parts to replace to allow me to safely burn unleaded fuel.
>....

As a bare minimum, install hardened steel seats for the exhaust 
valves while it's in the machine shop.

If you plan to drive it more than 50,000 miles in the next 10 years, 
or drive it hard like racing or regular trailer towing, then also 
consider Stellite exhaust valves and hard seats for the intake valves.

I also like bronze valve guides for the longevity, particularly 
100,000 miles or more.  They are relatively cheap but require .0010" 
to .0015" additional stem clearance to accomodate more inward thermal 
expansion of the guide, so some machine shop might give you a hard 
time about using bronze guides (or might get it wrong).

Umbrella type valve seals are optional.  They could reduce oil 
consumption some.  If you use iron guides, install unbrella seals on 
intake valves only, as iron exhaust guides need a little oil.  For 
bronze guides you can use the best valve seals available, as bronze 
is self-lubricating and doesn't need the oil.

$.03,

Barney Gaylord
1958 MGA with an attitude (and 370,000 miles)
http://MGAguru.com