Dan, as you know, I am running Evans waterless coolant in the slant, and have been good with it. However, in the thread you linked us to in a recent post you indicated you were running yours at atmosphere pressure, without a pressurized cap. I am NOT doing that . I have the standard 14 lb cap, and am wondering if I am missing one of the benefits of Evans in doing so. The coolant never gets over 220 on the hottest days sitting in traffic, which is well below its boiling point. Seems I recall 234 as the boiling point.

So here are the questions:

1. Can I just loosen the top cap to relieve the pressure and run it that way? What are the pros and cons of that? If I loosen the cap at the flowover connection, would that equalize with atmosphere and not put stuff on the ground?

2. How will doing so effect the flowover/expansion tank operation. This is plumbed in like a factory unit, with a higher cap added to burp the system, and to add, or check coolant level. . Will running with no pressure cap mean now filling it always at the top cap in the top hose. Seems if it does not build pressure it will not suck coolant back in from the overflow tank.

3.What will happen if it does boil over? It seems the excess will then be on the ground and not in the flowover tank. If I loosen the cap at the flowever tank connection which is on the radiator just like factory units, then the atmosphere would be free to equalize through the flowover tank. Maybe that is the way to go. Thanks for your thoughts on this.

I think I am missing out on a major benefit of the EVans coolant by running it pressurized.

Sam

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No, the car in question has a regular production 14-pound cap on it. The coolant expands (very) slightly as it heats up, but it does not generate steam as water-based coolant does, so it does not substantially pressurise the system. There's no geyser of hot fluid and steam if you remove the cap with the engine hot.
Take a look at the boiling point of the stuff—if it does boil over, I think you'll have a pretty good list of things to worry about before "where's the coolant going to go?".

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

What are the benefits of waterless coolant?

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65 4 dr. Valiant 200

Do a search for waterless coolant and you'll find it, there's a big thread on how it works and what the benefits are.

Basically two reasons that I can remember:

1. No water means much higher boiling point. With a water based coolant, microbubbles form in the cylinder head. Since heat travels better through liquid than gas, the bubbles hinder heat transfer from head to coolant. Waterless coolant has no microbubbles - therefore better heat transfer.

2. No water means much higher boiling point. Since the coolant doesn't boil, it does not have to be pressurized to remain in its liquid state. This keeps your hoses, clamps and gaskets happy.

Downside? Costs (certainly in the UK).

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1960 Plymouth Belvedere 4 door sedan
Stock 60 225
Push button 3 speed Torqueflite
Right Hooker

See here (and follow the link to the precedent thread)

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I'm sure I read all that before I put it in. My old guy memory is at work. Dan your explanation of the lack of pressure build up was excellent.

I guess this means that under normal operating conditions, no coolant cycles in and out of the overflow tank.
Thanks.
Sam

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Yes, and zero corrosion.
Yes, and less pinging.
…and radiator seams…and heater core seams…and water pump seals…

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

So, what happens if you have a coolant leak and need to top off on the road? I assume trying to mix in water or ethylene glycol would not be a good idea.

Lou

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Home of Slant6-powered fun machines since 1988

Coolant leaks are much less likely with an unpressurized system, because everything that could potentially leak is under much less stress and a leak goes drip……drip……drip rather than FSSSHHHHHSHSHSHSHHHHH!. I carry a jug of Evans in the trunk, but in a catastrophic emergency you top up with water and get where you're going. This doesn't ruin the Evans coolant, it just means you collect it in a clean catch bin and bring it to just over 212°F 'til the water's done boiling off.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Great. That's what I was thinking would work. I will probably try some.

Thanks,

Lou

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Home of Slant6-powered fun machines since 1988

what is the freezing point?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Sounds like pretty good stuff. Their site is giving me a server issue (could be this old computer), so I wonder: how long lived is this coolant? Or is that a non issue, on account of the "no corrosion" properties? IOW is there no additive package to wear out / be used up.

It won't freeze at a temperature that will actually be experienced. At -40°, the stuff is about the consistency of a not-very-fresh frozen margarita. Still pumpable with ease, and will thin to normal liquid consistency as soon as the engine begins warming it up. At 0°F (-18°C), its viscosity is almost identical to straight ordinary ethylene glycol coolant.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

If nothing happens to contaminate it (oil or trans fluid or exhaust getting into the cooling system), lifespan is theoretically indefinite.
Right. Because there's no water, there's no electrolytic corrosion, hence no need for sacrificial corrosion inhibitors that are eventually depleted and no buildup of rust/scale.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Howdy Dan,

You've gotten me interested in this stuff, and I'm considering it for my dragster. The reference material didn't address it's "slipperyness" (yep, fabricated word) on asphalt vs ethylene glycol, a major consideration at the strip, as eg's outlawed. Do you by chance, have any subjective experience with that aspect?

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Sex, drags, and rock & roll.
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