Strange Westerbeake overheating problem

[Capt. Mike]

Charlie
There was far more than a 10% difference between the temperature with coolant and the temperature with water only. First of all I was using a more concentrated coolant solution than 50%. It was closer to pure coolant. With coolant the temperature runs away - reaching nearly 200 deg F. in less than 10 minutes under load. With water only I can run under load for over an hour with the temp under 180 deg F.

Mike

[charmc]

To be effective, the solution should have a pH around 12. The powder called caustic soda, or lye, is best. Red Devil or Drano brand powder/crystal drain cleaners are mostly caustic soda, or you can get it at a chemical supply store. The chemical name for caustic soda is sodium hydroxide, NaOH. The best way is to add a little at a time to water (NEVER add water to caustic powder: it will boil violently and splash; can burn skin or cause eye damage.) until the pH is 12. There are simple test kits with strips that will change color with pH, makes it easy to determine if you have a strong enough solution. Warm water, 100 -110 F works best. Just like muriatic acid, use eye and hand protection.

[alan white]

Use Sodium Hydroxide, available as conditioner for fryers available at any restaurant from the dishwashing boy or at any restaurant supply. They use it to extend the life of frying oil when it gets too acidic. It's like a strong lime.
I owned a restaurant equipment repair and sales company for a few years. We used to add it to water, and heat it to near boiling. It is very effective.
I would hook up the intake to a pail of it (mix a cup to five gallons to start) and run the engine, and catch the hot exhaust water, cool, and reuse, etc. Shutting the engine down once hot, it should sit and stew. You'd be amazed what stuff will come out.
Wear gloves and goggles.

Alan

[charmc]

Mike,

Sorry, I was looking at the 20 deg difference only. Yes, pure glycol will only be 60-70% as effective in removing heat as water; in fact, the PCM engine manual states that operation with glycol solutions higher than 50% can contribute to overheating. For your location, it might be best to use a 20-25% glycol solution plus a corrosion inhibitor. That would give anti-freeze protection down to about 10 F, and the corrosion inhibitor will give the internal protection needed. The low glycol % should help heat transfer.

This article has some interesting information:
http://www.perfprotech.com/store/Art...ng-basics.aspx

[alan white]

Originally Posted by Capt. Mike

Charlie
There was far more than a 10% difference between the temperature with coolant and the temperature with water only. First of all I was using a more concentrated coolant solution than 50%. It was closer to pure coolant. With coolant the temperature runs away - reaching nearly 200 deg F. in less than 10 minutes under load. With water only I can run under load for over an hour with the temp under 180 deg F.

Mike

There's a threshold point when temperature "runs away". It may be that your engine is so close to that threshold that the difference between plain water and coolant water is enough to cross that threshold. You could compare it to a point where you're comfortable in a winter jacket, but add just a bit of extra heat and you begin to be hot and uncomfortable. At a certain point, heat is not exchanged neutrally, but begins to accumulate.
The raw water system is not efficient, either because of blockage or surface resistence to heat transfer, or flow volume. Impellers do break up and migrate, surfaces get scaly, and impellers with endwise gaps cannot keep up.
The most likely culprit is chunks of impeller (or something) lodged in an elbow or passage. All those places have to be checked, even if it appears that the flow is normal. I don't know if the flow splits anywhere, but if it does, you'll get normal flow and yet most of it is going around the obstruction and that area is getting hot.

[Capt. Mike]

The flow does not split, but it does go through the heat exchanger, the oil cooler and the transmission cooler. I will make up the caustic soda solution and run 5 gal half through, let the engine sit for an hour and then run the rest through. Before that I will remove all hoses and physically look for chunks of stuff. I had hoped that simply installing the thermostat that has been missing would solve the problem, but of course the law is that it is never easy.

Thanks
Mike

[H180DSC]

Hey Mike,

Here are a few points that you may want to consider. I am not familiar with your particular engine, so I don't know what kind of fuel system it has on it. Is it possible that the fuel setting on your engine has been turned up. If your fuel setting is turned up, and your engine is in good condition, it will be making more horsepower than the cooling system was designed for. Also, high air intake temperatures can cause high coolant temperatures. This can be caused by damaged intake piping, plugged air filters, damaged turbocharger. Is your fresh water cooling system a pressurized system? If so, is the radiator cap keeping the system at the appropriate pressure? I also agree with previous posts about the glycol content. It should not exceed 50%. You should also be aware that running on straight water can cause cavitation erosion on the cylinder walls.

[Capt. Mike]

I didn't know that the fuel rate was adjustable. The rate of consumption seems to be normal to me - it is about 2/3 of a gal per hour. I will reduce the amount of coolant in the mix. I did replace the radiator cap. The old one was a 4# and a 15# is called for. I replaced it with the 16# that was available to me.

Thanks
Mike

[crzhors]

This thread sure got academic, Did you ever put a thermostat in it? Did you remove the exhaust manifold and inspect it for blockage? K.I.S.S.

[TeddyDiver]

This is an old thread but just making a note here. Charm is right! Never use pure coolant. Actually 1/1 water/coolant is the max in everything else (including Austrian wines ) except aeroplane antifreezing..

Quote from Charm:
"Yes, pure glycol will only be 60-70% as effective in removing heat as water; in fact, the PCM engine manual states that operation with glycol solutions higher than 50% can contribute to overheating. For your location, it might be best to use a 20-25% glycol solution plus a corrosion inhibitor. That would give anti-freeze protection down to about 10 F, and the corrosion inhibitor will give the internal protection needed. The low glycol % should help heat transfer."

[FAST FRED]

In addition the use of distilled water with the antifreez will cut down on problems in the long run.

Tap water may have too high a hardeness or be acidic , so the few cents a gallon are a wise investment.

FF

[tranmkp]

I have the same thing on my w70. Been thru all the above mentioned - only excuse I can find is that Im way over prop'ed.

[FAST FRED]

only excuse I can find is that Im way over prop'ed.

Overproped is frequently an owner CHOICE to lower the engine RPM at cruise.


To not overload the engine , be sure to run the warmed engine to max rpm, for about 15 seconds , and note the RPM.

Then reduce the rpm by at least 10% or even better 300rpm.

Mark the Tach and you have your max cruise rpm.This will give good fuel use and not overtax the engine.

FF

[crzhors]

greetings, just an odd experience to share,Repairing a Universal cooling leak issue,reassembled and had a immediate overheat. started chasing and going nuts about flow...Well we'd let air in the cooling system which manifested itself in the lines going to the Water Heater, the air pocket had us pulling our thinning hair out! Carefully bled and forced some water thru the coolant lines and all was well again. Just a thought... Cheers Oh,yeah, get a CenTech IR Thermo!

[kenJ]

That is probably the most common cause of overheat. When working on engines that have hot water heating loops I always make it a point to bleed those lines even if the work was in a different part of the cooling system. They seem to attract air bubbles.