[DeTomaso] Thermostat

[jderyke at aol.com]

 No; the primary reason was the then-brand-new smog requirements by the U.S DOT that mandated low emissions both on initial start-up AND while running. So the Cleveland (and 351-M/400 truck engines) got an experimental quick warm-up cooing system plus an exhaust heated intake to speed warm-up & reduce unburned fuel while running on the choke.  Maybe partially due to the difficulty in finding the 351-C thermostat cheaply enough- most vendors have them in stock but not for chain-store prices. Some 15% of the coolant flow will go around the rad if an unmodified Windsor thermostat is used in a 351-C  without a 5/8" freeze plug in the brass washer. . The unmodified Pantera does not have enough cooling margin to absorb that 15% extra heat. The 400 block (and maybe the 351-M) used a cast-in-place iron block extension with a drilling that did the same function as our brass washer.
 

 

-----Original Message-----
From: Joseph F. Byrd, Jr. <byrdjf at embarqmail.com>
To: detomaso <detomaso at poca.com>
Sent: Thu, Aug 27, 2015 8:53 pm
Subject: Re: [DeTomaso] Thermostat


I though the primary reason for the elaborate thermostat flow path for the Cleveland was due to localized "hot spots" in the block/head passages
that will boil before the thermostat opens.  Therefore the controlled bypass flow is to have excessive bypass during warm-up to sweep the "hot spots". 
An orifice bypass like used for other blocks would require so much bypass it would rob the flow to the radiator when the thermostat opens.
Joe/NC



 
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   No; the primary reason was the then-brand-new smog requirements by the
   U.S DOT that mandated low emissions both on initial start-up AND while
   running. So the Cleveland (and 351-M/400 truck engines) got an
   experimental quick warm-up cooing system plus an exhaust heated intake
   to speed warm-up & reduce unburned fuel while running on the choke.
   Maybe partially due to the difficulty in finding the 351-C thermostat
   cheaply enough- most vendors have them in stock but not for chain-store
   prices. Some 15% of the coolant flow will go around the rad if an
   unmodified Windsor thermostat is used in a 351-C  without a 5/8" freeze
   plug in the brass washer. . The unmodified Pantera does not have enough
   cooling margin to absorb that 15% extra heat. The 400 block (and maybe
   the 351-M) used a cast-in-place iron block extension with a drilling
   that did the same function as our brass washer.

   -----Original Message-----
   From: Joseph F. Byrd, Jr. <byrdjf at embarqmail.com>
   To: detomaso <detomaso at poca.com>
   Sent: Thu, Aug 27, 2015 8:53 pm
   Subject: Re: [DeTomaso] Thermostat
I though the primary reason for the elaborate thermostat flow path for the Cleve
land was due to localized "hot spots" in the block/head passages
that will boil before the thermostat opens.  Therefore the controlled bypass flo
w is to have excessive bypass during warm-up to sweep the "hot spots".
An orifice bypass like used for other blocks would require so much bypass it wou
ld rob the flow to the radiator when the thermostat opens.
Joe/NC