[VAC] Manual trans, heat and towing in the desert

[harriswest <harriswest@xxxxxxxxxxxxx>]

A stick will always be more dependable, generally speaking.  But again,
get what you are comfortable with.  Standards will get hot when they
run, mainly from conduction from the block and radiant heat from the
exhaust.  250F operating temps are typical and a manual grind box can
handle just fine.  Unless your engine itself is overheating or you have
other obvious mechanical problems it won't ever get "too hot."

I have to take polite exception to the Doc's comment that the gears tend
to be more substantial for the horsepower than in an auto - although
individual models may vary.  Manual trans are designed so that the gears
are physically slid in and out of engagement, auto trans use constant
mesh planetary arrangments which don't have to be beefed up to withstand
crashing together.  Gears in a Chevy TH350 auto are pretty flimsy
looking compared to those in my Dana T18 manual, but the auto will
handle 400+ HP and the Dana will grenade with much over about 250 HP. 
As further anecdotal example, when you rebuild an auto, you replace the
brake bands and control units but the gears themselves rarely break.  I
can't say that for a manual trans.  

However, the Doc did get it absolutely right as far as the torque
converter being the major heat source in an auto.  This bumps the normal
operating temp up to around the 350F range, the trans oil cooler will
dump all excess heat into the radiator, and you will not be able to run
the SoCal deserts with stock configuration in the summertime with Air
Stream in tow.   

Again, I have to take polite exception to the Doc, who said:

 I think the typical temperature rise of engine and
> automatic transmission is a whole lot more than the difference between
> Iowa and Death Valley summer temperatures, so the ambient is a small
> part of the temperature effect.

I've driven Palm Springs/indio/coachella valley, without trailer, at
120F air temp, and can attest that at that temp ambient is definitely a
consideration.  Your cooling system is not designed for more than about
105F, and at 120 your cooling system simply can not rid itself of excess
heat.  Holding speed down to about 40MPH allowed the system to reach an
acceptable equilibrium, with the A/C off and the heater running full
blast.  This with brand new radiator plus ancilliaries such as hoses &c,
fresh valve job, ignition timing on the money, etc etc etc.      

If you insist on towing under these conditions, get yourself a
heavy-duty racing radiator and supplemental electric cooling fans, along
with a separate heavy-duty trans cooler.  It'll cost you $600-700 but
you won't overheat.  If you stay where ambient is less than 100F and
keep the speed below about 45-50MPH when it gets hot, a standard "tow
package" should do fine, even with that integral trans cooler boiling
away in your rad.
-- 
Mike Harris
Austin, TX (formerly Lost Angeles)