With all this talk about water temperature, I thought I'd share
observations with my two Sprites. I'm hoping the collective wisdom can
help me resolve these as winter projects. I have two Sprites with very
different water temp characteristics. I'd like to know why they are
different and what is best; a more efficient radiator (aluminum), a fan or
First Sprite is a '59 Bugeye with an original 948 engine with a 5-speed
Datsun. I've not rebuilt the engine; I cleaned and reinstalled it during
restoration since it seemed in good shape. It has good compression. Oil
pressure after warm-up is about 40 at speed and about 10 at idle. The '59
does fine in traffic. I can come off the highway, sit and a light and the
motor will cool to 185. At speed on a hot day however, it gets hot. I've
not tried over 40 miles on the highway. It will warm up from 185 to nearly
205. That's when I get concerned and take back roads. It's not a problem
in the cooler spring and fall.
Second Sprite is a '69 MkIV with a 1275 bored to 0.020", but otherwise
stock. I've been driving it regularly for 8 years. After warm-up, oil
pressure is 60 at speed and 40 at idle. On a hot day in the summer, its
fine on the highway as long as I'm moving. Get into traffic however and it
heats up. On days that are over 90F, temperature can go to 205 if I sit in
traffic for over 20 min. Fortunately, this doesn't happen often.
Neither car has actually overheated. However, I'd like to install a more
efficient cooling in both. Why are they different? What's the fix?
Blue '69 Sprite
White '59 Bugeye