Cadillac 346 engine coolant

[houseboats1]

Can any one tell me what type of coolant to use in a 346 engine please
Thanks Mark I'm in Australia it doesn't snow where we live

[Jim Miller]

Mark
When I purchased my '41, the guys all said to use the original type green Prestone. They also cautioned about using a strong flush. So I just flushed with plain water. Looked at Evans Waterless Coolant but too many pros and cons so I decided to stay with original. It was also suggested i find a spare 9 pound radiator cap to keep on the shelf.
Jim

[Bill Ingler #7799]

Jim:  As you probably already know , the RC-7 cap for your 41 is getting hard to find and expensive. If you do not drive your car for a long period of time, back your cap off a half a turn. If a cap is screwed tight on the radiator for a long period of time, the thin rubber sealing gasket on bottom of the cap can become stuck to the sealing flange of the radiator neck. Taking the cap off can destroy the rubber seal. I had it happen on my 47. I now put a tinny amount of silicone lubricant on rubber seal to prevent sticking of the rubber seal to the neck flange .  Bill

[Jim Miller]

Thanks Bill. I did find a spare RC7 cap. But I will follow the other suggestions also.

[Mike Josephic CLC #3877]

Whether it gets cold enough to snow or not, you
should still add antifreeze to your cooling system.

I addition to providing protection against freezing
of the coolant, antifreeze also has corrosion inhibitors
that protect the radiator and engine block against
the effects of water.  Water, as I'm sure you know,
corrodes the radiator and causes rust in the engine
block. Antifreeze also contains a lubricant for your
water pump.

The standard "green" antifreeze is what you need.

Mike

[Bobby B]

The standard "green" antifreeze is what you need.

Agree with all of the above  ......
                                  Bobby

[houseboats1]

Thanks for the good advice. Much appreciated!
Regards Mark

[Quentin Hall]

Where in Oz and what car do you have Mark?

[amolnayak]

I have recently restored my 1940 Lasalle 52 coupe and been driving it around in Mumbai India. The temperatures here are 32C minimum and generally bumper to bumper traffic. My engine is unopened and I had flushed the block thoroughly by opening the water jackets and fixing new ones.

Initially i used only pure coolant and I would loose almost 2 litres of it on a 10km ride in no traffic. However after the advice of some seniors here I have diluted the coolant heavily and even in crazy traffic the temperature at the head does not exceed 200F . I have been checking with a laser thermometer. The loss of coolant and water is negligible. The key really is to get the correct water coolant proportion so the rust is inhibited but yet there is enough water which is a better conductor o heat than the coolant.

[35-709]

Commonly a 50/50 mix.

[houseboats1]

Where in Oz and what car do you have Mark?

I live in Nowra NSW and I have a 1939 60 special