[FWDLK] Leaded vs. Unleaded:

["David Grove Grove Automotive" <groveautomotive@xxxxxx>]

Hello all Lookers:  On this "lead" subject, I would like to submit the
following:  Having been an auto repair technician since the late 60's,
(90%) Chrysler) it has been my experience that lead (or some form of valve
seat lubrication) is necessary on pre-1973 Chrysler engines.  Chrysler did
not have "hardened" seats prior to the 73 model year.  (actually, the seats
themselves were not of a hard material, bit the head was induction-hardened
after the manufacturing process.)  If you look at a new head that was
induction-hardened, you can see that the entire area encompassing the
exhaust valve seat is "blue" colored.  I'm sure everyone has his or her own
opinion about the need for lead, or a subsitute, but here is a good case
scenario to consider:  My 71 Chrysler Town & Country -(purchased in 81 with
50,000 miles on it,) was used extensively for towing (race car - about
5000 lbs w/trailer).  I did not take the engine apart until the car had
140,000 miles on it (I only removed the engine then because it leaked
everything everywhere!).  There was no sign of damage from the use of
unleaded gas.  The reason for this is that the engine probably had a steady
diet of leaded fuel from 71 up until the time that there was no longer any
leaded fuel available.  The lead imbeds itself into the valve seat, and the
face of the valve, and remains there until it is removed by machining (a
valve job).  I put later model heads on it at the time of overhaul - the
reason follows:  My daughter had a 318 Duster some time back, and I rebuilt
the engine (a 67 model 318), and the exhaust valves hammered into the seats
so badly in a year's time that the ngine would not even start!  Trust me -
this car was not used for towing.  She drove it maybe 8000 miles before
this happened.  She did NOT use any "lead subsitute".
It is my opion therefore, that if you do not have some sort of valve seat
lubrication in a non-hard seat engine - you need some.  I'm sure there are
many engines out ther that have and will suffer no ill-effects, but once
you do a valve job, you're on thin ice!                 Just thought I'd
offer a little first-hand experience.   DaveG.