Re: fuel additive
Posted by Owen_Dyneto On 2011/4/17 9:58:00
Before 1955 most cars came with hardened valve seats and hard valves.
For all the years and engines I'm familiar with, Packard did not employ induction-hardened seats or seat inserts, though they did use austenitic alloy for exhaust valves. As has already been noted the tetraethyl lead did increase anti-knock properties which isn't of particular importance to Packard owners, but the other property that lead imparted was for valve face and stem lubrication, especially needed for exhaust valves to minimize seat battering and recession if an engine is going to have a regular diet of high speed driving. This is the reason most good engine rebuilders suggest installing hardened exhaust valve seats. I think Chrysler was one of the first to use hardened exhaust seat inserts in their sixes, perhaps even pre-war (same war you're thinking of Rusty), but did not use them in the Plymouths & Dodges.
It's been posted many times here before, but let me again post a guideline chart about valve-seat recession. I still use TEL in my 56 Carib which sees a reasonable amount of Interstate speed driving. If and when I do a valve job I'll have hardened seats installed (available from NAPA) and be done with the TEL, you really need to use proper personal protective equipment when dispensing it.
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For all the years and engines I'm familiar with, Packard did not employ induction-hardened seats or seat inserts, though they did use austenitic alloy for exhaust valves. As has already been noted the tetraethyl lead did increase anti-knock properties which isn't of particular importance to Packard owners, but the other property that lead imparted was for valve face and stem lubrication, especially needed for exhaust valves to minimize seat battering and recession if an engine is going to have a regular diet of high speed driving. This is the reason most good engine rebuilders suggest installing hardened exhaust valve seats. I think Chrysler was one of the first to use hardened exhaust seat inserts in their sixes, perhaps even pre-war (same war you're thinking of Rusty), but did not use them in the Plymouths & Dodges.
It's been posted many times here before, but let me again post a guideline chart about valve-seat recession. I still use TEL in my 56 Carib which sees a reasonable amount of Interstate speed driving. If and when I do a valve job I'll have hardened seats installed (available from NAPA) and be done with the TEL, you really need to use proper personal protective equipment when dispensing it.
Attach file:
(55.70 KB)
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