[Amc-list] Leaded Gas and seats

["Bruce Hevner" <scramblr@xxxxxxxxxxx>]

>My 70 304 has all the original head pieces and parts, except for guide
seals and gaskets.
>Might I be correct in saying that the additive commonly known as lead
substitute doesn't really do >squat to protect the valves and seats??
>Are the lead substitute manufacturers then just pulling our legs??

Unless it's got REAL lead it's pretty much a waste of money.
I'll bet your 304 is an automatic used on the street? Old engines that were
used with lead tend to show less wear until a valve grind removes the lead
buildup. Low RPM lightly loaded engines can get away without hard seats
(depending on the mfg). At least for a while, sometimes quite a while.

I had a customer who was restoring an OLD stake bed truck that had a
flathead in it. He tried to get away with just using ( I believe 104 had a
lead substitute) so he wouldn't have to remove the engine just for a valve
grind.  I can't remember how long it lasted but it wasn't more than a few
months. He came in asking why his valve clearance was always closing up. He
ended up yanking the engine so I could put hard seats in it. Cured the
problem.
 Heavily loaded and /or high RPM engines run the exhaust valves MUCH hotter.
Without the lead to protect them the valve tends to "pick up" pieces of the
exhaust seat, leading to failure.

I am currently working on a 68 396 BB Cheby engine restoration. The original
seats and valves are in pretty good condition. You can actually SEE the
shine of the lead still on the seats. I will be putting hard seats in it
though.
 But hey,,, that's just ME!
Bruce Hevner

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://splatter.wps.com/pipermail/amc-list/attachments/20080707/d7651dbf/attachment.htm 
_______________________________________________
Amc-list mailing list
Amc-list@xxxxxxxxxxxx
http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list