From what I remember, 1955 was the last year for the hardened seats. The 354 in 1956 was the first one to require leaded gasoline, but who would of thought that anyone would have to state that. It seemed like lead was here to stay.
You are right. When I started at Chrysler in 1949 all engines had steel exhaust valve seat inserts that were pressed into the cylinder head. Continued experience with gasoline with the tetraethyl lead additive showed us that we could eliminate the hardened valve seat and save this money.
(Apparently, the lead deposits provided a kind of a lubricant between the valve face and the valve seat.) I don't remember the year that we removed the steel valve seat inserts.
The phase out of lead in automotive gasoline started in 1976 and was completed by 1986. It was illegal to put tetraethyl lead in gasoline after 1985.
Burt Bouwkamp
----- Original Message ----- From: "Ernie Stepney" <
estepney@xxxxxxxxx>
To: <
mailing-list@xxxxxxxxxxxxxxxx>
Sent: Friday, November 10, 2006 7:52 PM
Subject: RE: IML: Lead Additive
Flathead sixes from at least 1938, exhaust only, maybe earlier. 300D
392's had hardened exhaust replaceable seats as well.
Ernie and The Black Bitc_!!
-----Original Message-----
From:
mailing-list-owner@xxxxxxxxxxxxxxxx
[
mailto:mailing-list-owner@xxxxxxxxxxxxxxxx] On Behalf Of aeyn
Sent: Friday, November 10, 2006 12:09 PM
To:
mailing-list@xxxxxxxxxxxxxxxx
Subject: Re: IML: Lead Additive
Regarding this subject.
Does any one recall when Chrysler started to put the hardened
valce seats in the engines. I remember something about they
started gradually putting in the hardened seats PRIOR to 1975 in
differnet model lines.
Æyn.
--- Dan <
sunup@xxxxxxxxxxxxx> wrote:
> There were a number of posts recently about lead additives but
> I don't
> remember anything about "amounts per gallon". I followed the
> directions on
> the product I bought of 1/2 ounce per 5 gallons. Considering a
> half ounce is
> such a small amount, does this sound right? Also, can someomne
> tell me what
> might happen toa 440 or 413 if it is run with premium unleaded
> gas and no
> lead additive? If it is harmful, would it be immediate or
> gradual over time?
>
> I'd also like to join in with thanks to those of you who fought
> for our
> freedom. The character and courage of men and women like you is
> responsible
> for the freedoms we all enjoy today.
>
> Thanks You!
>
> Dan Collins
> 67 Crown Coupe
>
>
>
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