<VV> Hot

[Jim Simpson]

Not to be argumentative, but while there may not be any published data on
Chevrolet doing temperature and other durability related testing on the 140
engines, I'd be really surprised if they didn't perform those tests.  They
certainly did the dynamometer testing to determine HP, torque, fuel
consumption, ignition timing settings, etc.  They almost certainly recorded
engine temps during those tests.  Chevrolet normally does pretty extensive
road testing, including hot weather/desert runs for any new design.  But,
like you, I haven't seen any published data about how the engine performed
installed in a car.  Maybe it's buried somewhere in the Chevrolet archives.

That said, the first thing I'd check would be the cylinder head temp
switch.  As others have pointed out, they've been known to trigger at lower
temperatures as they age.  (I ran into the same thing with a temp switch on
one of Chevy in-line, water-cooled sixes years ago.  Warning light caused
by a bad switch.)

Jim Simpson
Group Corvair

On Tue, Jul 17, 2018 at 6:24 PM, James Davis <hurricanehazel16 at gmail.com>
wrote:

> There is no record of Chevy testing the 140 engine for temperature.  The
> 140 heads have 27% less fin area then the other heads due to the larger
> intake and exhaust ports.  It stands to reason than they would run
> hotter.then the average engine but I suppect they would not overheat in
> normal operation.
> Jim Davis
>
> On Tue, Jul 17, 2018 at 3:25 PM, Jim Simpson via VirtualVairs <
> virtualvairs at corvair.org> wrote:
>
>> I don't see any particular reason to change the oil.  Synthetics like
>> Mobil
>> 1 are good to pretty high temps --  according to their web site, the Mobil
>> 1 oils can go to 500 F!  I suspect that's a "flash temp", not sustained
>> driving, but unless you melted a bearing or something, I doubt you've hurt
>> the oil.
>>
>> The bigger issue is why did you get a overtemp warning light?  Even at 108
>> outside temp, the engine shouldn't overheat at any reasonable highway
>> speed.  Chevrolet tested the engines during development at higher temps
>> and
>> speeds than that.
>>
>> So check the cylinder head flashing, the fan belt, oil cooler to be sure
>> there's nothing blocking air flow.  And don't overlook the cylinder head
>> temp switch.  They've been known to go bad and trigger at lower than
>> specified temperatures.  (Do you have a cylinder head and/or oil temp
>> gauge?)
>>
>> Jim Simpson
>> Group Corvair
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