How to run a 100%COOL Engine

 

Radiator type

A few words on water

Measuring coolant temperature and fans

Use a proven high flow coolant pump

Pressure caps

Running lean

Electric fans

Hoses

 Opinion may differ but we think the following suggestions will get you well on the way to managing the heat produced by any high performance engine. The article is very generic so if it doesn’t fit exactly with what you are doing please feel free to contact us.

With years of experience supplying 100%Cool waterless coolants and systems for race and fast road vehicles, Classic, Vintage, and now high powered diesel trucks we have put together some suggestions you may want to consider when designing or modifying your cooling system.

 

A proper cooling system on a modern or classic car engine is a critical science that every owner needs to get to understand. The result of even the most basic engine modification is designed to produce more horse power but a lot of stock cooling systems are pretty near the edge already and the latest tweek can take the cooling past the tipping point.

Engines prefer to run on the cool side and it is beneficial for maximum horse power to keep them in the mid 70’s C  where ever possible. But race engines will often see 100 or beyond in the heat of battle. We are confident that even at temperatures beyond 100c your engine can run very well and efficiently without critical failure using 100%cool waterless coolant. After all metal is not going to melt at 120 degrees is it! But you can’t do this with a water based coolant running at realistic operating pressures ( we’ll ignore what F1 does at 150 psi)

 

The use of a 100%Cool waterless engine coolant alone is not going to solve design faults, but it will help you get around the problem and save your engine from failure but to get the best out of your cooling system we like to get the following points right first.

 Radiator type

 Aluminium radiators are a must for most applications, copper conducts well but you can get more surface area using aluminium. A 1.25 inch two row aluminium radiator will cool just about anything up to 450hp (depending on the size) If designed correctly it will perform very well. A word of caution to those with steel engines running aluminium radiators consider the effect that electrochemical corrosion may have on the radiator if you are going to run a water based coolant, with 100%Cool water less engine coolant the problem is non existent. For any mix of exotic metals and alloys in engine construction the use of 100%Cool waterless coolant is a must especially for museum vehicles in storage. There are several experts in the field of radiator design who will best advise you on the most efficient radiator for the space and horsepower you have like Alan Docking (ADR) or Serk lean on their expertise use them, we do.

 

It is possible when running 100%Cool waterless coolant to run a much smaller radiator that is efficiently designed in preference to a stock model this will reduce weight, every ltr of coolant weighs approximately 1kg.. It is also possible to reduce drag when choosing radiator position. Stalling  air through the radiator by adjusting the radiator angle is also a worthwhile experiment. I say experiment because you may be short on space and you will need to move it within the confines of the car. Also there is no point  ramming air through the radiator into a confined engine department with little room for the hot air to escape, you may have to consider bonnet louvers or vents and gurney flaps to increase the air flow out of the engine compartment.

Big gains are to be had from selecting the correct radiator type ( surface area), coolant and air flow.

 A few words on water

 Water  has several admirable qualities, it is a brilliant conductor of heat that is until it goes past boiling, once boiling it forms steam and once its steam in the cooling system it doesn’t condense well and stops being an efficient coolant. Particularly when it comes to hot spots within the engine. Try putting water onto a hot weld it just jumps off, it does just the same in your coolant jacket around critical hot spot areas caused by problems like detonation and this is why the metal fails it goes way past the coolant temperatures shown on your gauge and causes critical metal failure.

We are talking performance engines here and we need a coolant that is going to perform 100% all of the time way past boiling point. My other reservation about water is its corrosion properties, sure anti corrosion technology can be added OAT and HOAT you know the red or green stuff. But the addition of water is the weak link in the corrosion process. Enough said.

 Measuring coolant temperature and fans

 So where do you measure the coolant temperature from? Manufacturers put a sensor in the block or at a convenient point ( for them) where they can get a sensor into the coolant gallery. Ok so we know the engine coolant temperature at this particular point . To know the average coolant temperature we need to get a reading as near to the out hose as possible, the sensor can be housed in an aluminium hose joint. If you are running a fan it is also a good place to put the fan controller. We have a hose joint mounted adjustable fan controller that will do the job nicely. We are currently developing a temperature control array that will house both the heat sensor and fan control in one unit at the top hose end. The fan control can be adjusted to operate at a preset temperature so now the control becomes pro-active instead of a radiator mounted re-active fan switch. The advantage of this is that it will let you know the real time mean coolant temperature leaving the engine via the coolant heat sensor, and the preset radiator switch will give the radiator fans ( if fitted) advanced warning of the coolant temperature that’s going to hit the radiator and starts them early before the heat sink sets in, you now have a grip on the heat management of the engines coolant temperature.

 Use a proven high flow coolant pump

 We can calculate the flow of coolant required if we have the horse power figures and number of radiators and there size. Once we know this we can calculate the ltrs or gallons  per minute required to carry enough coolant to the radiator.

Contrary to popular belief, slowing the coolant through the radiator does not improve heat dissipation! This is a widely held myth that is completely contrary to the laws of heat conduction physics. The higher the flow, the more heat will get carried and displaced. The use of high flow pumps is a major step up.

The pulley size will need to be looked as well ideally you would want to run as near to 1:1 as possible when using 100%cool waterless coolant. But depending on the revs pulled you may want to under or overdrive your pump gearing. Using a correct impellor vane designed for pumping without cavitation along with ceramic bearings will pay huge dividends. Provision for an air bleed will also need to be made air is not a good coolant and can wreck a pump.

 

When using electric pumps the original pump will have to be modified so that the electric pump can run continuously, we have seen electric pumps cool a winning car at the Le Man 24 hour so we know they work and reliably. The disadvantage of electric pumps is that they will pump at a given speed and flow rate all the time, you are not able to throttle the coolant with the engine revs. This makes it very important that you know the required flow rate of coolant for your engine using a flow rate calculation; we can provide this for customers. In some cases (V engines) you may find that you need to run two pumps, one for each cylinder bank when using an electric system. Slave pumps are also available to help with the coolant flow back from the radiator. All of this requires power from a battery/alternator so think carefully before ditching the mechanical pump

 Pressure caps

 When using coolants with a high water content in a high performance engine you would expect to run a high pressure cap of some 20+ psi. This extra pressure increases the boiling point of the water but at the same time puts extra pressure on the hoses and head gaskets. What this increase in pressure cannot do is prevent the water from jumping off of hot spots within the engines cooling jackets, so in an engine prone to detonation it is not going to solve the problem.

 

Because 100%cool will not boil within an engine it does not have to be put under any pressure to cool efficiently, we recommend a 4-7lb cap just to keep the fluid within the system but on vintage cars running an open pressurless cooling system the product cools efficiently at zero pressure, these old cars running on water alone dump the water every time the car stops when hot due to heat sink.

 

The use of a low pressure cap will be better for the hoses and gaskets, but only possible in a high performance engine when you use 100%cool waterless coolant.

 Running lean

 If you assume everything else is set up correctly as explained above then the next major cause of cooling problems will be the engine running too lean. Correct set up of your carb or injector system plays a major part in keeping your engine cool.

Rolling road tuning is never a waste of money.

 

Electric fans

 

Always choose a high quality electric fan, how much air does it move cfm (cubic foot per minute) what are its continuous watts or amperage. Watts or amperage are a great yardstick to whether the fan can move the air it claims. You get what you pay for I’m afraid so go for a proven design. Remember though you if you are going to pump 1000’s of cfm’s of air into the engine bay make sure it can get out or the extra air is going to stall in your engine bay.

 Metal braided cooling hoses !

 I know ! but we’ve seen it, do not use braided metal hoses or a metal sleeve to a rubber hose as a custom look on your coolant hoses. The use of metal will actually act as an insulator and contain the heat in the system. Conversely the use of aluminium or copper tubes in the system joined with silicone /rubber hoses will dissipate heat. Remember  when using aluminium tubes on a race car they must have swaged ends as per the current MSA Blue book as well as a good hose clamp that grips evenly and will not cut the hose. If the hose/tube is all metal it’s ok to go if its rubber coated in metal definitely don’t use it for coolant plumbing.

We recommend and use Samco/type silicone hoses.we can also supply a Classic looking wound hose in silicone as well, beware of some cheap blue silicone hoses that do not have sufficient wall support.