[DeTomaso] Sodium valves

Wed Feb 18 17:00:02 EST 2015

 Thanks Charles

I wouldn't be surprised if sodium valves were used in Nascar hemis or Boss
429 engines too. I just don't recall any production engines with them, but I
could be wrong.....
Ken Green says the LS7 uses them !
I'm surprised at that. I wonder if that's in the GM engine as produced or an
aftermarket thing?

Ken, do you know?

Barry

  _____  

 From: Charles De Francisco [mailto:drfortinbras at gmail.com] 
Sent: February-18-15 3:41 PM
To: B. SEIB
Subject: Re: [DeTomaso] Sodium valves

Hi Barry your info was almost rite on.  Ford did offer the sodium valves on
the 427 engines for thr Cobras used in their race program  

There was a issue with the nos valves as the sodium corroded the inside
causing them to come apart as they were drilled to make the stem hollow..the
story I heard was the sodium was to provide cooling of the valve stem in
endurance racing...we used some
In drag race engines as they were somewhat lighter..a much better set up
would be manley stainless valves..?..Pete Coleman
At manley in Lakewood n.j. 732-905-3366 would be able to help you on this
issue.

On Wednesday, February 18, 2015, B. SEIB <oldwheel at shaw.ca> wrote:

Hi Robert
Sodium valves were a feature in the 375HP version of Corvette 327 engines
with fuel injection. I don't recall sodium valves being used in other US
standard production engines. Maybe some other exotic engines did. Later
valve steels and technology made the risks and expense of sodium filled
valves obsolete in HP engines. The idea originated in aircraft piston
engines back around WWII, I think, and was related to trying to cool exhaust
valves under high stress loads.

The 1971 Cleveland 351-4V engines in Panteras (and Mustangs,etc.) had high
compression closed chamber (quench) heads, single point distributors, small
square bore 600cfm 4300A carbs and 2 bolt mains. The Boss 351 was the only
351C to get 4 bolt mains, dual point distributor and the large spreadbore
Motorcraft 4300D carb in 1971 along with high compression CC heads.

Some people have said that some 1971 4V engines found there way into very
early 72 Panteras, but probably only in early January 72 cars. The 1972
Cobra-jet engines would have entered production in Sept of 1971 and by the
end of 1971, DeTomaso was likely to have used their engine stock on hand and
have received new Cobra-jet engines from Ford. I understand DeTomaso was
generally receiving engines only about a month or so after they were
produced in the US plant.

1972 Panteras came with Cobra-jet engines that had open chamber (lower
compression) 4V heads but with 4 bolt mains, dual point distributor and
large spreadbore Motorcraft 4300D carb. This was the strange result of Ford
trying to recover some of the power lost to stricter emission standards for
1972. The compression had to come down for unleaded gas and Ford upped the
RPM to try to get some oomph back. They retarded the cam timing and hopped
it up a bit to get the power at higher revs, thus the dual point and 4 bolt
mains.

1973 and 74 went downhill from there, with increasing emissions and lower
compression.

So...the best heads were in 1971, but everything else was better in 1972.
Unless you have a 1971 BOSS 351 engine, which never came in a production US
market Pantera. Pity that.

Barry

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-------------- next part --------------

    Thanks Charles

   I wouldn't be surprised if sodium valves were used in Nascar hemis or
   Boss 429 engines too. I just don't recall any production engines with
   them, but I could be wrong.....

   Ken Green says the LS7 uses them !

   I'm surprised at that. I wonder if that's in the GM engine as produced
   or an aftermarket thing?

   Ken, do you know?

   Barry
     __________________________________________________________________

    From: Charles De Francisco [mailto:drfortinbras at gmail.com]
   Sent: February-18-15 3:41 PM
   To: B. SEIB
   Subject: Re: [DeTomaso] Sodium valves

   Hi Barry your info was almost rite on.  Ford did offer the sodium
   valves on the 427 engines for thr Cobras used in their race program

   There was a issue with the nos valves as the sodium corroded the inside
   causing them to come apart as they were drilled to make the stem
   hollow..the story I heard was the sodium was to provide cooling of the
   valve stem in endurance racing...we used some

   In drag race engines as they were somewhat lighter..a much better set
   up would be manley stainless valves..?..Pete Coleman

   At manley in Lakewood n.j. 732-905-3366 would be able to help you on
   this issue.
   On Wednesday, February 18, 2015, B. SEIB <[1]oldwheel at shaw.ca> wrote:

     Hi Robert
     Sodium valves were a feature in the 375HP version of Corvette 327
     engines
     with fuel injection. I don't recall sodium valves being used in
     other US
     standard production engines. Maybe some other exotic engines did.
     Later
     valve steels and technology made the risks and expense of sodium
     filled
     valves obsolete in HP engines. The idea originated in aircraft
     piston
     engines back around WWII, I think, and was related to trying to cool
     exhaust
     valves under high stress loads.
     The 1971 Cleveland 351-4V engines in Panteras (and Mustangs,etc.)
     had high
     compression closed chamber (quench) heads, single point
     distributors, small
     square bore 600cfm 4300A carbs and 2 bolt mains. The Boss 351 was
     the only
     351C to get 4 bolt mains, dual point distributor and the large
     spreadbore
     Motorcraft 4300D carb in 1971 along with high compression CC heads.
     Some people have said that some 1971 4V engines found there way into
     very
     early 72 Panteras, but probably only in early January 72 cars. The
     1972
     Cobra-jet engines would have entered production in Sept of 1971 and
     by the
     end of 1971, DeTomaso was likely to have used their engine stock on
     hand and
     have received new Cobra-jet engines from Ford. I understand DeTomaso
     was
     generally receiving engines only about a month or so after they were
     produced in the US plant.
     1972 Panteras came with Cobra-jet engines that had open chamber
     (lower
     compression) 4V heads but with 4 bolt mains, dual point distributor
     and
     large spreadbore Motorcraft 4300D carb. This was the strange result
     of Ford
     trying to recover some of the power lost to stricter emission
     standards for
     1972. The compression had to come down for unleaded gas and Ford
     upped the
     RPM to try to get some oomph back. They retarded the cam timing and
     hopped
     it up a bit to get the power at higher revs, thus the dual point and
     4 bolt
     mains.
     1973 and 74 went downhill from there, with increasing emissions and
     lower
     compression.
     So...the best heads were in 1971, but everything else was better in
     1972.
     Unless you have a 1971 BOSS 351 engine, which never came in a
     production US
     market Pantera. Pity that.
     Barry
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