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Saturday, November 7, 2009

JH gets an improved cooling system.....

The Jensen Healey came standard with a 2-row radiator and a yellow plastic fan. I never had any serious problems with engine temperature, but after I had the engine rebuilt with a much higher performance package ( more Horsepower), I noticed my temperature gauge creeping past the 3/4 mark when idling in the city. This was not overheating, but on a prolonged idle combined with a high outside temperature, things could get dangerously close to overheating. I drove it the rest of the summer with my eye on the gauge as I really didn't want to stress things to much. I always made sure I was near a highway or back road for a quick cool down once the car got up to speed. Even when the car is cruising on the highway, the temperature was a couple needle widths above the center mark.

I decided to check out my upgrade options to get me a little more piece of mind when idling for long periods. I brought the car to a mechanic with quite a bit of experience with Lotus Esprits ( which some versions used the same engine more or less). He recommended I perform the following steps to solve my cooling problem as he used the same steps when dealing with other healey's and Esprits.

1) Check water pump for proper operation and ensure it is in spec.
2) Replace thermostat with a 170 degree opening version
3) Send out radiator to be modified
4) install radiator shroud - available for healey's.

Cost breakdowns and results follow:

1) Pulled water pump, found some Old LOTUS tech manuals for the 907 and measured the water pump play and vanes to ensure within specification. The water pump checked out fine.... Time.... 40 Minutes - $40.00

2) Replaced thermostat and gasket with new one from Lotus supplier... Cost ..$11.00
no charge for labor as it was part of the water pump checking.

3) Radiator modification - Change to 3-row, modifed cooling tube fin layout. 1 hour remove and replace $60.00 - special "Hot Rod" radiator ( that's what the radiator shop calls it) $275.00

4) Install Radiator shroud - Parts $40.00 ( he had a used one kicking around) labor $25.00

Total Cost = $451.00

The results were phenomenal and well worth the bucks. The car idled for over 45 minutes and never went higher than 1/2 to cente r ( 1/4 of entire range) Outside air temperature was 55 degrees. I am confident when the outside temp heats up the car will operate in the mid range on the gauge.