Someone on the list recently suggested measuring the coolant pressure inside
the block between the mechanical water pump and the outlet
thermostat/restrictor. Sounds like a good idea---if the pressure is higher
than necessary to prevent boiling or pump cavitation, too much HP is lost
driving the pump at high RPM. And running the pump well above the design RPM
could cause even more cavitation.
Had an OHV V8 once that blew out freeze plugs at high RPM, solved the
problem by grinding down the pump impellers to half-size and had no freeze
plug or cooling problems thereafter.
Lance,
No cooling problems here in PA, running about 15-20 degrees below normal for
this time of year.
----- Original Message -----
From: <dthomssen@neb.rr.com>
To: "Land-speed Racers" <land-speed@autox.team.net>
Sent: Monday, March 14, 2005 10:15 PM
Subject: Fw: Am I crazy or just dumb?
> This question came up more than 50 years ago in the age of Flathead
(wrought
> iron engine) powered dirt-track racing in stock cars and sprinters with
> heating problems. One cure was a washer restrictor to slow down (?) the
> flow. Everybody thought that was the reason, and it worked. Later we
found
> that the stock water pumps were cavitating (creating bubbles) from being
> wound so tight and the washer increased the pressure on the pump and
reduced
> the tendency to cavitate. The bubbles reduced the contact of water to
> wrought iron and caused real hot spots. Other cures included modifications
> to the pump to reduce cavitation.
>
> Today's water pumps surely must be turning RPM's beyond their design RPM
> and restrictors may be doing the same thing as they were doing 50 years
> ago- reducing cavitation.
> Dave the Hayseed
> It's Spring in Nebraska
|