rad and coolant, TPEFI related

[Shannen Durphey]

George M. Dailey wrote:

> I can vouche for this personally, I got "smart" and put a 160f thermostat in
> my GM TPEFI and it fell flat on it's face as far as economy goes. Put the
> 195f back in and magic, no problem. Now I have thoughts of running it right
> at 219F, just below fan turn on temp. A kind gent sent me some info on just
> what it takes to run at the high temps. He mentioned a guy that ran an
> engine temp of 250 or 300F, I think. The main problem was he had to use 100%
> pure ethylene glycole with no water what so ever. Water would flash to steam
> and create abnormally high radiator pressures.
>
> Aint it cool'
> GMD
>
> gmd at tecinfo.com

  I dug through my books and came up with one by David Visard which talks about
using propylene glycol.  There's a whole section on cooling systems and yes, he
answers Tom's initial question about coolant moving too fast.  He talks about
some testing done where the coolant flow was reversed, and the coolant temp was
raised to 260 deg.  Pure propylene glycol was used to reduce cavitation and hot
spots in the heads.  The water pump was driven at 90% of crank speed and the
radiator size was increased to handle the flow.  16:1 compression yielded 1.7
more hp, no change in fuel consumption, and 17.7 cfm less air usage over 190
degree coolant temp,  all with no detonation.

One day I'm going to look into reverse flow cooling.  Maybe on the next efi
conversion.

Shannen