1937 Flathead

[excalibur]

What is the best antifreeze to use? Ethylene Glycol or the newer multi use antifreeze. Also on motor oil, what is the best type of oil in the flatheads? a multi viscosity or a straight 30 weight?

 

[Jim Brierley]

Ask on the "early V8" section of this forum. To me, all are good, so use whatever you like, just stay away from old type of such things, such as non-detergent oil.

 

[katy]

Ethylene Glycol, multi viscosity.

 

[rotorwrench]

A full amount of both in any brand is better than none. I still use the old green stuff but I don't have any aluminum radiators or anything like that. The 50/50 mix may not be good enough for a very cold environment like way up north depending on the OPs location. 70/30 is better for the cold country where temps can go below zero degrees F.

 

[Mister Moose]

For those in real cold areas you could look into polypropylene glycol, aka the pink stuff. High antifreeze concentrations don't really freeze, they slush. Plus they don't expand when freezing like ethylene glycol mix does. It's more expensive, and you need to make sure you get the engine ones with anti-corrosion additives, the drinking water pipes antifreeze has no additives.

 

[katy]

Ethylene glycol chart: