Coolant flow

I found this bit interesting
"Years ago, cars used low pressure radiator caps with upright-style radiators. At high RPM, the water pump pressure would overcome the radiator cap’s rating and force coolant out, resulting in an overheated engine.

Many enthusiasts mistakenly believed that these situations were caused because the coolant was flowing through the radiator so quickly, that it did not have time to cool. Using restrictors or slowing water pump speed prevented the coolant from being forced out, and allowed the engine to run cooler. However, cars built in the past thirty years have used cross flow radiators that position the radiator cap on the low pressure (suction) side of the system. This type of system does not subject the radiator cap to pressure from the water pump, so it benefits from maximizing coolant flow, not restricting it.
"

i.e in the last 30 years they came up with a better system.... the muscle car era ended 50 years ago


1) this thread was prompted by another thread
2) the car in question was described as mostly standard apart from rear gearing that rasied the cruise rpm on the highway quite a bit.
3) its mostly standard so it has an upright radiator with a 1960s style cap.... i.e in comparison to what you find today on a modern car, according to the quote above, the cap is potentially vulnerable to pressure problems.
4) "Many enthusiatsts" could have been wrong or right on the issue quoted above, it depends on radiator efficency, how hot the motor gets and if the appariasl of the siutation quoted above is correct.
5) slowing the flow stopped the cap venting and the car didn't overheat becasue it "allowed it to run cooler" regardless of if that was becasue it was venting due to pressure and a crap cap and then overheating. Or if it was overaheating causing the cap to vent.

Slowing the flow made the issue go away for those running upright radiator and a low pressure cap in a position vulnerable to venting due to system pressure.

so there was a well known solution to stop you, i won't say "over heating", loseing all ya coolant, that worked for old style radiator and cap set ups. and you are saying becasue it worked Its WRONG wrong wrong wrong...

6) the OP is running a low pressure cap and has an upright radiator
7) providing quotes from companies who have a vested interest in selling their own kit based on thieir own appriasal of a situation does not necessarily mean that their apppriasal of the situation is correct it could mean that it is biased in order to sell more kit. I suspect as they are talking about systems built with 21st centrury knowledge and research, that if you do as they say, "buy our kit", all will be well. Most of us are not doing that.

I presume if i was to buy a full set up from the supplier you quote i would get a matched set of components, pump capacity, beautifully matched to a radiator where fin design, bore no. of passes and the material it is made from have been scientificlly tested for the best outcome. I'd get appropriate pipes with or without a spring dpending on their bore and material, and a themostat that provides in this case no restriction becasue the pump causes such a pressure difference that that chances of cavitation are reduced.

Basiclaly id be running a modern style radiator at a much higher pressure with its cap in a much less vulnerable position to avoid inadvertant venting, and i'd be pumping that coolant Damn fast. All would be well, it may well be the best cooling system ever... and i'd be really pleased with it, everything they say in their documents would be correct for my all NEW KIT

BUT the OP in the other thread is running a 1950s designed cooling system and he is spinning that pump way faster for sustained periods of time on the freeway with his drag race oriented gears.

applying 1 part of the theory discussed in your numerouse linked documents....
one advancement in thinking from the last 30 years and leaving that same old pump that same old stat and that same old radiator technology in place will not get the results he wants. he just wants to drive it down the freeway without a 2 gallon bucket of water in the trunk.

applying Modern thinking based on a new design of cooling system, that many of us will Never ever have, to every request for help from people running antiquated systems.
Then being so damn stroppy about it doesn't help any one, it just blows his thread out to 4 pages...

and you had the temerity to suggest i was being arrogant


lets look at this another way, If I applied those tiles they used on the space shuttle to the front of my valiant it doesn't mean i'd survive re entry

I'd need the suit and the rest of the bleeding kit to go with them...

I belive you are probably a very knowledgeable man I could learn a lot from you. But you are not gonna get the chance to pass that knowledge on unless you change your attitude.

that seems sad.

please note i never said you were wrong....!


Dave

I don’t know how old that tech page is. Maybe it’s 10 years old. Who knows.

What I do know is part of one part of one of the tech pages (I’m not going back through to see if what you quoted was part of or not) was discussing FLAT HEAD FORDS an what was done to them and why.

Like most things, what was done to the FHF (for good reason BTW) was wrongly applied to everything that came after it. And that’s exactly how **** like slowing coolant flow down keeps getting repeated.

I know you are looking for some thread to grasp to make slowing coolant flow down the correct thing to do but it is wrong.

My attitude is what it is because this same thing comes up on a regular basis and it gets damn old trying to educate and clean up the same error over and and over and over.

I could post another 20 links from 5 other manufacturers and you would quickly read them, pull out some quotes you think fit your myth and then spend 20 paragraphs defending the myth.

You will never learn because you refuse to accept that you won’t let go of the error.

And every time I see this error I will call it out.

There is a reason why guys are fighting cooling issues. One of them is not getting coolant and air flow correct. And that is get the coolant flowing as fast as you can (within reason…you have to keep the belt on and not have the mechanical fan explode if you use one) and do the same with air flow.

So…if someone wants to sit down and PLAN their cooling system (thats what should be done) this is what I would tell them to do.

1. Get the biggest 2 core radiator that will fit. It needs to be aluminum. Why? Because copper/brass may reject heat better than aluminum but what it can’t do is be made to is be made into shapes like 2 large (1 inch or bigger) cores and have enough strength. While you give up a BIT of thermal efficiency with aluminum, you gain that back and then some with it.

2. High flow water pump. I don’t care about the arguments about why the FSM says about how many blades with AC or non AC and all that. You want as many blades as you can get. The exception to that is the Flowkooler pumps because they use a different design. Either way, a quality high flow pump is a must.

3. A QUALITY high flow thermostat. IMO the best one (and only choice) is the Stewart Components thermostat. They are fully open by their rated temperature and they are very accurate. At the same time, you should be considering what temperature you want the engine to maintain. Again, my opinion is that any of the engines we discuss here should NEVER get over 180. Thats it. Any more than that and you are pissing away power. How so? You make the engine way more detonation prone. You can’t run as much compression. You end up retarding the timing to help reduce detonation, which can cause higher engine temperatures. If you want to run unorthodox compression ratios on pump gas then the goal should be 160 degrees and no more. You can run 12:1 (and probably a bit more if you are real careful and want to get your tune down to the gnats ***) on pump gas. Premium of course but it’s still pump gas. And that makes power. Everywhere. And driveability.

4. Fan selection. This is critical. I run a mechanical fan. I may try an electric fan down the road. If you are going to do an electric fan, make sure it’s a QUALITY fan, not some cheap assed junker. I hear the Ford Contour fans are what you’d want and that’s what I’ll try if and when I do it. For a mechanical fan, I use a stainless steel flex fan. I do not use any other. I have done testing in the past and what you save in HP from a thermostatic fan over a fixed fan you lose in temperature control. You need to move some air and I don’t like having the fan engage and disengage based on the temperature some engineer thought was best for a run of the mill engine.

5. To that end, you need to do whatever it takes to at least (at the VERY least) to find pulleys that are 1:1. The water pump should turn no slower than crank speed. Ever. Unless you are shifting at 8k plus RPM and you are worried about the fan exploding (you should be with an overdriven pump). Other than that, get the pump (and the fan if you have a mechanical one) as fast as practicable. I’m at 6% over and I’d love to double that.

If more people were educated in this area to the facts and science of it some of the companies that manufacture pulleys would make them. When I first started calling around to find pulleys every company said the same thing. We get one call for overdriven pulleys for every 200 calls we take for UNDERdriven pulleys. When guys still have bad thinking on this, why would anyone invest in pulleys to speed up the water pump?

The last thing is coolant. I know all the long hairs out there will say water is the best conductor of heat as a coolant medium. And it is. But the issue is my engines are expensive. And water (especially when it it heated and cooled hundreds and thousands of times during its life cycle) is corrosive to the block and heads.

Plus, I drive my junk year around so I need some protection from freezing. I have driven my car on days where the high temperature was in the high teens. Straight water will not allow that.

So you should be running something for winter and corrosion protection.

I am using Evans for several reasons (I’m not sponsored by them, I don’t get product for free and I’m not married to the owners daughter…all of which I’ve been accused of) and two of them are freezing and corrosion protection.

But a HUGE bonus is Evans coolant does not require system pressure to increase the boiling point of the coolant. You have have 220 degree coolant temperature and you can take the cap off while the engine is running and you won’t get burned half to death from hot coolant exploding out of the radiator. That right there should make you consider the product. From a pure safety standpoint.

There is also another bonus from running near zero system pressure and that is with near zero pressure (you may get 1, maybe 2 PSI but probably not) is the fact that it’s easier on the coolant lines, core plugs and even the head gaskets.

With near zero system pressure the load on those parts is significantly reduced. Running 14, 16 or 20 PSI as some guys do is harder on the hoses, core plugs and head gaskets.

If you follow these simple guidelines, you can drive your car right through downtown hell on the hottest day of the year and not have an issue.