Antifreeze Mix Ratio for Ford Lehman 120

[jleonard]

Being from southern New England, 50/50 mix is the gold standard which protects to -40F.
Normal low winter temps are usually around -5 F, but we have seen -20 F.
We need the protection.
A properly working cooling system will be fine at 50/50.

 

[Xsbank]

Coolant is essential in a diesel. Even with cast blocks, as the piston rises and falls, the cylinder distorts an amount when the engine runs. You need enough coolant with the correct additives to prevent damage and enough coolant to protect against freezing where that is an issue. It doesn’t last forever but if you use test strips annually or when you do your maintenance you can tell if the additives are toast and the coolant needs replacing. Caterpillar sells them. Actually all engine manufacturers do too.

If you have a coolant filter, change it according to the book, it contains the additives so they are automatically topped up.

Gas engines, go ahead and use water. Diesels are different because of their high compression.

Its not just “antifreeze” it is an essential part of correctly operating a diesel. Follow the manufacturer’s recommendations.

 

[rgano]

Ran the same boat, same engines for many years with 50/50. No reason to put tap water in 'em if it is full of minerals. Might be just as simple to get pre-mixed and just don't worry about it.

 

[Evergreen1111]

My father was the senior vice president at Union Carbide / Prestone for many years. He had numerous boats including 120 Ford Lehman's in an ocean Alexander. He did all his own maintenance and never used a 50/50 blend. He would use the Straight Prestone and add water until the ratios and his meter met spec.

 

[BigTime]

Do NOT mix colors.

 

[psneeld]

Colors don't matter....look for chemistry and compatibility.

 

[psneeld]

My father was the senior vice president at Union Carbide / Prestone for many years. He had numerous boats including 120 Ford Lehman's in an ocean Alexander. He did all his own maintenance and never used a 50/50 blend. He would use the Straight Prestone and add water until the ratios and his meter met spec.

So he didn't believe in what he was partially responsible for?


Plus...the 50/50 premix is good enough for the vast majority of us.

 

[SteveK]

Do NOT mix colors.

Colors don't matter....look for chemistry and compatibility.

Get a room. :lol:

50/50 premix is good for topping up.

 

[Nomad Willy]

50/50 is OK but they say 40/60 is better.
60% water.

But the real reason you use AF is to raise the boiling temp under pressure depending on your system pressure via the coolant cap. With 50/50 mix you raise your boiling point to 265 degrees f. That’s w a 15lb cap. A 7lb cap would probably protect against boiling up to about 236 degrees f. I think my Mitsu cap is 13lbs.
Chemical stability and probably water pump seal lubrication too.

 

[Evergreen1111]

So he didn't believe in what he was partially responsible for?


Plus...the 50/50 premix is good enough for the vast majority of us.

Marketing and convenience. Lazy is good enough for most people.

 

[psneeld]

Marketing and convenience. Lazy is good enough for most people.

good enough is good enough....nothng to do with being lazy.


lazy is when it's not good enough and you don't do anything about it.

 

[Nomad Willy]

I don’t think it’s lazy.
It’s simple enough for most to remember the ratio over long periods of time.
And there’s no confusion about it being 60/40 or 40/60.
In short 50/50 is helping us have/achieve a safe and effective amount of AF and water in their cooling system.
Nothing to do w lazyness.

 

[Evergreen1111]

To each his or her own. I'm just saying that I also don't make instant grits or instant oatmeal.

 

[jleonard]

I mix my own because it’s cheaper.
Somebody had to say it.

 

[Nepidae]

Asking ANYONE other than Brian Smith questions about a Ford Lehman engine is asking for trouble.

Bob Smith, the previous owner of American Diesel Corp, was also involved in the marinization of the Ford Lehman engine. He knew that engine inside & out and also provided parts and advice.

Bob has gone on to the next adventure but ADC (https://americandieselcorp.com/) with his son Brian at the helm is still in operation and can provide answers to any questions about the FL engine, provide parts and services.

Get in touch with Brian.

 

[foggysail]

And you don't really need distilled water when you are pouring it into an old cast iron block. Clean tap/drinking water is ok.
Save the distilled for batteries.

While I agree for the most part with your post, there are many auto engines that should have distilled water mixed with antifreeze for dilution. From personal experience with both a Ford Taurus and a Buick something (forgot exactly) the engine design engineers foolishly mixed metals in hard to get at places which eventually failed. The Buick.......intake manifold gasket, repair cost $800. Ford Taurus, timing gear cover gasket. That repair could cost more than the vehicle’s worth by requiring the engine’s oil pan to be removed in addition to everything needed to access the timing gear cover.

After my costly experiences I only dilute antifreeze needed for my old cast iron Crusader 454’s with distilled water. One can purchase 50/50 antifreeze and not worry about dilution.

 

[syjos]

Tap water may have, depending on your source, minerals, chlorine and flouride in it which could screw up the PH.

Distilled water is inexpensive, why not use it?

 

[Nepidae]

You completely missed my point.
I'm quite sure that Brian Smith knows more about the Ford Lehman engine than YOU.
You can mix anything you'd like and base your experience on a car engine and not a marinized engine or the Ford Lehman which is what the original question dealt with and what my response was aimed at.
MY point, was ask the expert or do what you want and possibly suffer the consequences.
I stand by my suggestion, you can do what you want.