I'm after a bit of advice here. A couple of my 1920s Pontiacs have a problem with boiling, I've rebuilt the water pumps, cleaned and flushed the blocks and radiators, am still using the original fans etc but they are still boiling. They are beautiful cars and a joy to drive but it has gotten to the point where I've stopped driving them because I can't trust them.

I'm thinking of converting them to Evans waterless coolant, this is supposedly a lifetime coolant with a boiling point of 375 degrees. It isn't cheap so I'd like to hear from anyone who has actually used it before I go and buy it.

Coolants » Engine Cooling Systems

If it is any good I'd probably even put it in the F3, it gets well over 100 deg where I live and I want to drive the truck regularly.

 

I'd think about the root cause before I considered running the cooling system hotter. Have you checked the obvious? Is timing right? Not does the damper mark show it as being correct. Damper rings move. So, find TDC and verify the timing marks. A degree wheel can do wonders too. Barring that, set it with a vacuum gauge.
Is the timing curve right?
Is there excessive slack in the timing chain(s)?
Have you started them from cold and watch inside the radiator fill neck for the thermostat to cycle? They do have thermostats, right? Contrary to some folks' beliefs, a thermostat does help to keep the cooling system, and thus the engine, cool.
Are the radiator caps holding pressure? If not, or if it's much lower than designed, the system will boil at a lower temperature.
Have you cleaned out the radiators?
Do the water pumps push water?

I really doubt that you're running enough horsepower to warrant using anything other than normal coolant. That's my 2c anyway.

 

I have thought about the root cause, at great length. These engine do not have rubber dampers or timing marks on the front pulleys, they use a mark on the flywheel. I have set the timing using this as well as using a vacuum gauge and have done test runs with timing in various degrees of advance and retardation. It might take a few miles less or a few miles more to boil but it still will. The engines are rebuilt and timing chains are new and tight and set correctly, timing advance curve is mechanically controlled, I have used original springs as well as reproductions and custom made, no difference, not a big issue on an engine with a redline of 3000rpm anyway. They do have thermostats, I've tried them with the thermostats in and out and with different sizes of restrictor plates. The cooling systems on vintage cars are zero pressure so cap sealing and pressure rating aren't an issue. Radiators have been cleaned and de-scaled and water pumps have been rebuilt with new impellers and are pushing water well. I think there is a flaw in your thinking in your last comment, horsepower and heat are not necessarily proportional.

This has been an ongoing issue for over 12 months, I have systematically gone through all the areas which can cause heat and am confident I have exhausted just about all possibilities. New radiators might solve it but new honeycomb style cores are almost $3000 each, too much to spend if the waterless coolant might solve the issue. What I'm really chasing here is opinions from people who have actually used this product.

 

I've got no experience with zero pressure water cooling systems, i'm sure they cant work well even in best condition.

have you asked this question at HAMB? lot of "vintage knowledge" there also.

Hokey *** Message Board - THE H.A.M.B.

 

I did not mean to be insolent. i'm sorry if I came across that way. That is far more "vintage" than I expected here. Perhaps if you were a bit more specific about the vehicles than "old Pontiacs," somebody with direct experience could chime in.

I do feel that horsepower and heat have a direct relationship - with the caveat that efficiency does not change. Clearly, the cooling system in your vehicles is insufficiently efficient. Good luck with your endeavors. May we see pictures?

OK, I woke up. You did say "1920s Pontiacs." My mistake. I did not read it that way earlier this morning and I apologize.

 

It's all good, I probably shouldn't be allowed to reply to posts first thing in the morning, definitely not pre-coffee anyway. It does say in the second sentence though, 1920s Pontiacs.

Efficiency does change, it has to. Newer engines convert far more of the chemical energy held in fuel into kinetic energy and less to heat, this is part of what allows power and economy figures to keep climbing for roughly similar displacements. Vintage engine produce a lot more heat and less kinetic energy, hence the generally massive radiators. The engines in question are 200 cid, if they were working at the same efficiency as a newer engine they should probably make 100+ HP, instead of the 57 that they do make.

I agree that the cooling systems are not working as efficiently as they should. Honeycomb radiators are notoriously difficult to clean out and have very fine passages, I'm certain that new radiators would fix the problem but I can't really afford to drop 6k into a pair of radiators at the moment, the F3 is hoovering money out of me. The cars are only just boiling if that makes sense, I think if the boiling temp was 10 deg higher they'd be ok, but it's not and with a zero pressure system it can't be altered like modern systems can, hence the potential change of coolant type.

 

Good advice, I'll head over there now!

 

Ask and you shall receive.

 

Cool cars.

Have you tried straight water? Or any of the cheaper additives like Water Wetter or Purple Ice? not sure if they are available over there.

Likely both the rad and block have a buildup of rust and scale after all of these years....there may not be an easy fix. Sorry, I can't answer your question directly...

 

I have indeed tried straight water, no change. I've heard of water wetter but never seen it over here. The engines have been rebuilt and were hot tanked etc so scale in them should be minimal if any. The radiators very likely do have scale in them but honeycombs are about impossible to clean out, you have to be very careful even flushing them, they will not cope with being pressurised.

 

I just had a "Pavlov's dog" moment when I saw the pictures! Thank you for sharing. Very, very nice.

 

Ha ha. Glad you like them. It's killing me not being able to drive them, I use them as daily drivers generally, the poor old 29 in the middle is clocking up the miles.

 

I have not used the Evans product, nor Water Wetter. Can you clarify, are your cars boiling while using straight water, or with an antifreeze mix? Are they boiling under moderate ambient temperatures?

If they are boiling with even a 10% glycol solution, I fear your problem is that your radiators are just not rejecting heat fast enough. If so, no fluid change is going to help.

The Evans product literature is vague about the things that are important; heat transfer coefficient and heat capacity. I suspect it is significantly more viscous than glycol antifreeze, or at least similar, which would mean it is harder to pump (hence they offer "upgraded" water pumps). It would be unusual to have a higher heat capacity than pure water (glycol is about 60% that of water), so really all it offers is that it doesn't actually boil at typical cooling system temperatures. To take advantage of that, you have to run it under pressure, and since you can't do that, I don't see any purpose for your cars.

I understand the issue with cleaning a honeycomb radiator, but I have to believe there is an industrial water treatment vendor in AU who can point you to a solution that will safely remove scale. Plate-and-frame heat exchangers have the same issues, but are nearly always SS. Cleaning them is still a 50-50 shot. I don't know if you can get away with it on your cars, but re-coring with a straight-tube core of a more modern design might be your best solution. I can't imagine it would cost more than $500 - $600 a car. (not cheap but a long ways from a new honeycomb)

 

Beautiful cars my friend . While we in Canada have our own set of problem regarding temperature as it relates to engines . When I have a problem I seek out the advice of the oldest mechanic I can find and invite him out for the day . If he was a gear head farmer combination then all the better . If those cars spent all their lives in Australia they must have had a solution back in the old days .

 

Have you read temperature differences between the top and bottom of the radiator? Is the radiator doing the job? Fill radiator with water, pull hose from bottom connection and see how fast water exits. Should drain very quickly. Flat belt or V type? Fan spinning at speed all the time?