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MG MGA - Operating temperature

Hello,

I now have about 1100 miles or so on my MGA and thought I might share some of my experience and what I think I have learned.

My car (non running when I got it) came equipped with an old radiator which showed signs of being previously patched and of having had an intimate relationship with the cooling fan. Of course I naturally cast it aside and installed a shiny new radiator from VB in the process of the restoration.

The car would run well over 200 degrees always, and when I put the spurs in it and laid its ears back (70-75mph highway speed) it would settle around 230 and maybe up to about 235. Lower speeds might drop the temperature 10 or 15 degrees or so.

Part of my restoration involved the overhaul of the safety gauge by MOMA of Albuquerque. Some suggested probably it was registering a temperature too high. I caught my wife gone out of town and used her tea kettle to boil water for the bulb and proved that, indeed, the temperature gauge is almost perfectly accurate at boiling. This was not what I wanted to learn.

A conversation with The Guru (henceforth referred to as TG) suggested that there was not enough airflow through the radiator, and the likely culprit is the modern new manufacture radiator. Close inspection of my cast off radiator revealed that it is an orignal cell core MGA radiator. At TG's recommendation, I checked it for leaks, straightened the fins, gave it a coat of paint, and installed it in place.

This appears to be the silver bullet. My testing so far is limited, but the HIGHEST temperature I have observed so far is around 210. This was at sustained speeds of 70 or 70+ along with acceleration in that area. Keep in mind that I live in a hot (north Texas) climate with routine temperatures in the mid 90s (during my testing) to the low 100s.

BTW, the cell core radiator appears to be substancially heavier than the replacement radiator.

Comments and observations are welcome

Safety Fast! (and cool)

JMG
John Greenlee

Good news,

My old, original radiator seems great - temps at 50ish are about 190, with not much variation. Cooler here than there, though - however I didn't observe higher temps even on a recent 90+ degree day.

You should also check the rating of your thermostat. I belive mine is a 160* unit from Moss.

JIM in NH
AJ Mail

Jim,

I am trying to remember which thermostat I installed. It was the one my MG guy recommended. I believe it was either 180 or 190.

Keep in mind the thermostat only effects the minimum temperature.

Safety Fast!

JMG
John Greenlee

John, the new radiator I bought didn't seem to cut it. I had an old radiator re-cored by Bob West, and it made a world of difference.
If your car runs hotter at high speeds than it does at low speeds, try altering the angle of the grille slats so that they are more open to the air flow. Have a look at other MGAs to see what you are aiming for. There is information about this in the archives if I remember. It is best to remove the grille and carefully tweak each slat a little at a time top and bottom until it looks right. I used duck-billed pliers wrapped with plastic tape so they didn't mark the slats.
Lindsay Sampford

This thread was discussed on 14/06/2011

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