Operating temps

[Mike Rolica]

Ahhh yes the ole'90 deg 3.8 v6. Now you are trying to compare apples to
oranges.  That is a totally different story, but yes that is related to
heat.  Even though you had a the 160 deg stat in there, I bet that it was
about 240-275 deg around the exhaust port (have done testing on dyno.. about
560 hours) and combustion chamber on the center cylinders on each bank.
Like the Chevy 4.3l, the motor was basically a 90 deg v8 with 2 cylinders
missing.  The 3.8's big brother, the Buick 350 was notorious like the 403
and 350 olds motor for having problems with inadequate cooling system. They
ran extremely hot between center 2 cylinders.  Their oiling system also
sucked.. but that is another story. Also the 3.8 had thin deck surface.
Around .35-.45.  The new 3800 series with al. Heads have .875-.9" deck
surface with more space around combustion chamber and is thinner around ex.
bowl.  From my testing, experimenting and listening I have verified a way to
help get rid of this problem not only on the 3.8 but more for 350 Chevy by
running a sup line to the heads right under  ex ports 3&5 and 4&6.  Also if
you have ever done any testing you would find that 7&8  around the cylinders
run hotter.  Pipe a  sup line to Ls to RS on the intake on the back 2
cooling ports.  (I'm not trying to reinvent the wheel but just get up close
to a nascar some time and look how the cooling system is done) Just because
the fans kick on that high does not mean that every thing is just A ok. Auto
makers have to run them hot due to emissions. So if the engine life is a
little less, well they would be happy to sell you a new one :-)
BTW: Installing a petcock on the thermostat housing so that when you fill
they rad you get all the air out will also help.  Air pockets tend to
collect in high rough spots in the heads and turn into steam pockets. And
they do not move and end up creating hot spots :-)
Mike Rolica
EXT. 260
 :-)




My 85 Buick GN at 96K had to have the head gaskets replaced... It ran a 160 
thermostat from about 1000 miles on the clock and had Iron heads...  They 
had to be milled .015" to clean them up, so I don't think it's the heat.

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            David Cooley N5XMT           Internet: N5XMT at bellsouth.net
      Packet: N5XMT at KQ4LO.#INT.NC.USA.NA   T.A.P.R. Member #7068
    Sponges grow in the ocean... Wonder how deep it would be if they
didn't?!
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