Best aggressive coolant flush for Chev blitz

I will have to disagree with the comments regarding overheating being caused by removal of a thermostat. Very simply, a faster flow will remove more heat. If the myth about a fast flowing cooling medium causing overheating were true, we would all put smaller, slower cooling fans on our engines because we would want to slow down the air coming through the radiator to pick up more heat, right? Wrong. We do the very opposite- we increase the air flow to increase the cooling. Air, water, it doesn't matter. Its the same principle.

DD I think you misunderstand if the water flows to quick over the radiator it doesnt get a chance to cool the water

Its a bit like a if you sat a saucepan on a stove to boil the water it may take 5 minutes but if you dont leave it there long enough it will never boil

The same happens to the water in the radiator if it moves to quick it can neither absorb the heat from the motor or cool the water as it flows thru the radiator as the water is moving to quick for either of these things to happen

heat up a big lump of steel and quickly dump it in a bucket of water steam comes of and bubbles etc but the steel is still hot leave it in the water for a few seconds and the steel is a lot cooler


Paul

Sorry Paul, your still missing the point. Of course, if you don't leave the saucepan one the stove, it wont boil, because your not continuously putting heat energy into it. When the hot coolant hits the radiator, it breaks up from one solid mass of coolant into hundreds of little tubes, so your effectively putting a huge surface area on the water for it to give its heat up into. Think about the old timer way of drinking hot coffee- if you let the coffee sit in the mug, it will take some time to cool down. However, if you tip a mouthful into the saucer, it will cool very quickly and you can drink it. This is because you are breaking the mass down into a smaller amount and then you are giving it a huge surface area to give up the heat.

A radiator is designed and built from materials to give up heat quickly. An engine block, by design and materials, will not put heat into the water as fast as a radiator will give it up.

I would imagine that the no thermostat overheating myth would have come about because a layperson had an overheating car and they removed the thermostat to still have an overheating car. So then they say the water is now flowing to fast through the radiator. When they pull the radiator cap off, it may look like the water is flowing quite fast out of the top hose, and it is, but then the water has to spread out to cover the huge area, which slows the flow down considerably. What they don't consider the core is rotten, or full of grass seeds and this is why the radiator is not doing its job. Thermostats are very simple and the main reasons they fail is age or poor coolant. Those two points alone indicate that the cooling system is not receiving the proper maintenance and is probably why something else in the system has failed, but yet the easiest part to get to and remove gets the blame. I saw it happen all the time in my previous life as a diesel mechanic- customers self diagnosing a problem and ending up with problems so huge and costly, when the original problem was a cheap, easy fix or a bit of maintenance was required. I was fortunate enough to get taught fault diagnosis and the cause/effect relationship. This skill doesn't get taught much anymore and you will find more often than not, people throw blame and parts at the effect, instead of at the cause.

As a side note, I have worked as an Advanced boiler operator and a steam turbine operator for several years and there is a considerable amount of science in putting heat into water and then removing it again. It is not as simple as most people think.

I had overheating problems with my 1952 GMC fitted with a 1956 Blueflame turned out that the original water pump was to low on the radiator and i had to retro fit the right pump and adaptor plate I got from The filling Station in Lebanon Oregon worked really well and also fitted a more accurate electric temp gauge and don't get rid of the thermostat the water will move to fast needs the restriction and make sure your rad cap is the right one and is OK

DD Im not gunna have a bun fight over this

Paul

As was described, the thermostat is used to assist with the operating temperature of the engine.
It will hold water in the engine until a set temperature is reached.
This is done for the engine efficiency.
The thermostat will regulate water flow to the radiator as temperature levels dictate.
The reason it may cause an overheating problem is if it was operating incorrectly or stuck closed.
Most of the would be do it yourself cooling diagnosis experts rip the thermostat out, rarely check it's operation, because they don't know how, and throw it under the bench with the rest of the junk.
Personally, I don't think there is a cheap fix to any of it.
Diagnose it correctly, if you don't know how, ask someone to do it for you.
The cooling system design they were built with, mostly works under normal circumstances.
Playing with vehicles over a lifetime, I haven't seen many totally failed thermostats. I've seen a few impellers spin on shafts, but I've seen a whole lot neglected cooling systems resulting in blocked radiators.
The radiator as has been stated, has got a whole lot of small holes that block up very easily when matter other than water flys around in a cooling system.
We can talk about the situation from every angle till the cows come home.. Won't matter if you are a rocket scientist or whatever else.
If it has got to a point of overheating, it's very unlikely a flush will cure it, a flush could be a deemed a maintenance step, rarely a fix.
People diagnosed cooling systems for a hell of a long time without the aid of special equipment. Back when commonsense was a part of a person's tool kit.
In this instance, the writer of the initial post has roughly described the history, the operation and the maintenance.
Unless lady luck is flying around dishing out magic wands..
This ain't gunna be no 20 cent fix!

On this forum, many are dealing with aged and neglected vehicles.
To get them back up to a standard takes knowledge, time and money. Unfortunately it takes a balanced input of each to make it all happen...
And when that's all done, there's the maintenance to keep it that way.

And for what it's worth, my take on a radiator / cooling.
As big as the given space will allow, without being ridiculous.
As much air as possible being pushed directly through it.
The water needs to be kept on the move to allow it to cool.
A gallon of water sitting in a radiator for a minute isn't gunna assist the other 10 gallons sittin in a red hot block.
There must be a good flow for it to work.
There seems to be a bit of confusion about which bit does what and why goin on in this topic.
There's some good learning to be had from a few of the experienced blokes here.
Unfortunately, Google doesn't know everything all the time..

Keep on Ol Truckin...

The radiator is a better heat remover than the engine is a furnace - that is why we call it a cooling system.

Slowing down the water (within reason eg not so slow that the water boils in the engine before it reaches the radiator - what you get with dirty engine or blocked tubes) allows it more time in the radiator which removes heat at a faster rate than the engine can produce it. To maintain the engine in the desired temperature range there is an optimum water speed for each power setting which the thermostat senses as heat variations and opens and closes to stay within that range.

Quite separate from the overheating discussion. If you take the thermostat out, the engine temperatures will be all over the shop depending on vehicle speed, wind speed, fan speed, outsides temperature, water flow, and engine power instead of relying on the thermostat which automatically compensates for all these temperature inputs. You will certainly have an inefficient engine using more fuel and producing less power as it drifts from too cold to too hot as you motor up and down hills. The only reason for the engine to have a thermostat is to make it work properly. REGULATED cooling does this. There is no upside to removing a working thermostat.

Nearly all early cars and some up to the 1930's had a syphon system. No water pump but relied completely on warm water rising out of the engine into the radiator top tank, cooling in the radiator and dropping to the bottom to start the cycle over. This system worked very well on millions of cars. If you pull the radiator cap off say, a Model T Ford, you will see the hot flow is quite slow. In a well maintained Model T you got no more boiling than could be expected on modern cars. They were sensitive to blockages because they did not have the pump forcing the water through the restriction to compensate.

The pump is a crude device pushing as hard as it can all the time with much more water than is needed. The thermostat is the fine tuner that regulates the flow to the desired amount. If you start to see the engine overheating because of blockages it has been building up for a long time but being hidden by the thermostat and water pump that have been overcoming the problem until it gets so bad they can not cope.

Once we started getting cars with higher power output (more heat) we had to increase the cooling capacity and particularly maintain the more high tech engines in the desired operating range so thermostats and water pumps came in. The syphon vehicle temperatures were self regulating - hotter engine faster flow, nothing like a water pump. They warmed up quite well because there initally was no flow. Unfortunately they were seldom at the perfect operating temperature for maximum efficiency.

Lang

I'd test the system by feeding the engine water in the bottom hose and run it with the top hose disconnected.

This would prove water was or wasn't flowing through the block.

I would reverse flush the radiator into a container to see if an crap came out of it.

A visual inspection (through the inlet and outlet may tell if cores are blocked.

If it has blocked cores or doesn't flow much water, get your wallet out and give it to the Radiator man and he will take off the tanks and rod it to clean the cores.

If it can't be saved he can re-core it.

Unfortunately with a fairly corroded engine when it runs hot it tends to flake off the corrosion and dump it in the radiator.
It then runs hotter sooner and continues the process to block the radiator further.
Thermostats have two roles to play, the first is as said above is to regulate the engine temperature. The second is to create pressure in the block to help control cavitation.
Early engines had basic thermostats that only opened and shut, later ones also control bypass setups to allow quicker warm up.
Taking a bypass thermostat out ( or fitting the wrong one) can lead to overheating as the bypass is not shut off when the engine heats up.