Roger Garnett writes:
>Modern petrol does not contain lead. Standard seats will last reasonably
>under mild, or occasional use. Under high heat conditions, such as
>heavy load, or continous high RPM, the valves can recede rapidly.
>An older truck used for towing for example, will waste unhardened
>valves/seats in no time. The only guarrenteed fix is modern materials-
>installing hardened seats. Which will last better than un-hardened
>*with* lead!
>When you need do do any head work- valves, or grind the seats- go with
>hardened seats.
Monetarily speaking, this is not a major investment. At least on my MGB
engine, it was only another $36 to get hardened seats. So why not?
As for oil and breakin, I think the bad seals on my carb had a lot to do
with the smoking, I'm not running Castrol now but I'll switch back to it
in another 500 miles or so. I don't think my available data allows for
a conclusion one way or another (and no, I don't want to switch to
Castrol now to find out if it causes problems :-).
-Dan Dasaro
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