Howardrg
Well-known member
Would any one know if the thermostat is or could be a restriction in the system. This when fully open [operating temps ?]
Howard
Howard
Cooling System
- Thread starter Howardrg
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radman
R.I.P. Our Motorcycling Friend
n/t
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Howardrg
Well-known member
Nope not thinking of removing it. Just wondering if it was slightly less restricted, would the bike run any cooler [by a few degrees] ?
Howard
Some years ago I had an old truck. It was prone to overheat. An even older machanic drilled 3 x 5 mm holes in the skirt of the thermostat. Problem solved. Ran cooler, never overheated again.
Howard
Some years ago I had an old truck. It was prone to overheat. An even older machanic drilled 3 x 5 mm holes in the skirt of the thermostat. Problem solved. Ran cooler, never overheated again.
radman
R.I.P. Our Motorcycling Friend
n/t
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BrunDog
Well-known member
I was fixin' to call shenanigans on this raddy, but I believe jestal did the honors.
-BD
T
Tolly
Guest
A little off from thermostats, but has anyone heard of, or used, a product called "Engine Ice"? It's supposed to really help cool any engine; any downsides to it? I haven't seen it mentioned here, but am new.
Thanks
Thanks
vectervp1
Well-known member
I run Engine Ice in my CBR954 and really haven't seen the temps any lower. The main reason use it is because the tracks around here won't let you run ethylene glycol based coolant. You have to either have Engine Ice, Evans NPG, or distilled water and Water Wetter.
On a side note, it was recommended to me from some of the racers at the track that I should flush the radiator fluid twice as often as if you had normal radiator fluid. Don't know how true this is, but I flush it out in spring time just before the heat starts up.
radman
R.I.P. Our Motorcycling Friend
It seems everytime I post an answer to a tech question, jestal is sure to follow with a thesis on how wrong I am. I shall defer to him in the future, and just keep my stupidity to myself. He is, after all, and after having done further research on this, correct.
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radman
R.I.P. Our Motorcycling Friend
Tech Articles
The Highs & Lows Of A Cooling System
Paulsen, McFarland Discuss The Concept Of Flow Rates In The Cooling System
By Meghan Frazier
Photography: Meghan Frazier
Chris Paulsen is president of C&R Racing, Inc. based in Indianapolis, Indiana. C&R Racing manufactures racing radiators for sprint cars all the way up to Formula One machines. Paulsen is an expert source on all things “cool.”
Could you explain the concept of controlling water speed and how it affects the cooling system?
First of all, “controlling water speed” is not something a lot of attention is paid to. What I mean by that is, the cooling system in a race car—that being a water pump, a radiator and the means water flows through the block and cylinder heads—are all kind of a given thing by each manufacturer. We build our radiators to basically reject heat from the cooling system in the most efficient way possible given the race car and the racetrack it is going to run on.
Let me start out by saying flow rate through the cooling system is a very important thing. With recent technology, we have pretty well proven that the higher flow rates we can get, the more efficient the cooling system is. Many people still believe in the old technology of slower flow rates. However, we are changing them every day. They believe by slowing down the flow, there is more time to absorb the heat and energy from the block and heads. This gives the water more time in the radiator. Therefore, the heat will be pulled out of the radiator better.
Quite honestly, with today’s technology, we have proven it is quite the opposite. We tend to prefer high-flow-rate systems. Pump manufacturers nowadays, like Stewart Components and Edelbrock, are trying to build pumps that will flow as much as 100 gallons a minute. This rate is really more like 60 gallons a minute.
With that in mind, you have a water pump that is trying to perform a high flow rate through the system. Well, the cylinder heads can be restrictive with their water passages, which in turn slows the flow rate down to a certain degree. This restriction also raises the pressure in the heads and the block, which is actually a good thing. Pressure in the heads and block helps reject heat and keeps the air molecules and water compressed so they don’t form steam pockets. With lower pressures, air will actually expand and begin boiling. This results in local hot spots in the combustion chamber.
One of the main reasons we like to see higher flow rates is higher flow rates will actually absorb more heat and BTUs of energy from the metal surfaces. They will actually pick up heat more efficiently and carry it out of the engine and into the radiator. When it comes to the radiator side of things, the higher flow rates push the water through the radiator tube much faster so it creates a much higher velocity in the cooling tubes. This higher water velocity actually creates more turbulence in the water, which rejects heat much better. So, that is why we say the old rule of thumb “slow down the water flow so it spends more time in the radiator in order to cool it better” is really not correct at all. The higher flow rate and higher water velocity through the radiator core really goes a long way in helping that radiator reject the heat.
What kind of performance Advantage will you see when you go to a higher flow rate?
The biggest performance advantage of the higher flow rate is keeping your temperatures in check and cooling your engine better. As far as any performance other than that, there really isn’t any. The critical part of a cooling system is the combustion chamber area in the cylinder heads. This is where the combustion is taking place and where the bulk of the heat is generated. We have seen higher flow rates help keep these combustion chambers cooler. It keeps the air from separating out of the water and causing local steam pockets and localized boiling in those combustion-chamber areas. It also keeps good water-to-metal contact in those areas, which is the secret to keeping everything cool.
What happens if those metal combustion chamber surfaces get too hot? The engine will actually get a mild detonation. With most race engines, if it starts overheating, the driver will come on the radio and say the car is starting to lose power, is running poorly and doesn’t have the horsepower he had before. What is happening is the temperature increases more and more and those hot spots in the cylinder heads will actually start creating a detonation situation in the engine—it is usually just a mild detonation, but it can make the power drop off.
What can an average racer do about controlling water speeds or flow rates? Is it just a matter of what type of water pump they install?
Yes, pretty much. The flow rate is not something racers can really control. Basically, you want the maximum water flow rate you can get. My suggestion is don’t worry about doing anything to physically control the flow. The engine itself is going to control flow rate because of the passages and the water system. It is only going to allow so much water to flow through because it only has so much area to work with. Winston Cup teams use AN line that goes from the engine back to the radiator. The hose size they pick can be somewhat of a restrictor. In other words, it could be the thing in the whole system that is restricting how much water is flowing throughout the whole system. If that is big enough that it is not the restrictor, well then, the radiator becomes the next restriction point.
The Highs & Lows Of A Cooling System
Paulsen, McFarland Discuss The Concept Of Flow Rates In The Cooling System
By Meghan Frazier
Photography: Meghan Frazier
Chris Paulsen is president of C&R Racing, Inc. based in Indianapolis, Indiana. C&R Racing manufactures racing radiators for sprint cars all the way up to Formula One machines. Paulsen is an expert source on all things “cool.”
Could you explain the concept of controlling water speed and how it affects the cooling system?
First of all, “controlling water speed” is not something a lot of attention is paid to. What I mean by that is, the cooling system in a race car—that being a water pump, a radiator and the means water flows through the block and cylinder heads—are all kind of a given thing by each manufacturer. We build our radiators to basically reject heat from the cooling system in the most efficient way possible given the race car and the racetrack it is going to run on.
Let me start out by saying flow rate through the cooling system is a very important thing. With recent technology, we have pretty well proven that the higher flow rates we can get, the more efficient the cooling system is. Many people still believe in the old technology of slower flow rates. However, we are changing them every day. They believe by slowing down the flow, there is more time to absorb the heat and energy from the block and heads. This gives the water more time in the radiator. Therefore, the heat will be pulled out of the radiator better.
Quite honestly, with today’s technology, we have proven it is quite the opposite. We tend to prefer high-flow-rate systems. Pump manufacturers nowadays, like Stewart Components and Edelbrock, are trying to build pumps that will flow as much as 100 gallons a minute. This rate is really more like 60 gallons a minute.
With that in mind, you have a water pump that is trying to perform a high flow rate through the system. Well, the cylinder heads can be restrictive with their water passages, which in turn slows the flow rate down to a certain degree. This restriction also raises the pressure in the heads and the block, which is actually a good thing. Pressure in the heads and block helps reject heat and keeps the air molecules and water compressed so they don’t form steam pockets. With lower pressures, air will actually expand and begin boiling. This results in local hot spots in the combustion chamber.
One of the main reasons we like to see higher flow rates is higher flow rates will actually absorb more heat and BTUs of energy from the metal surfaces. They will actually pick up heat more efficiently and carry it out of the engine and into the radiator. When it comes to the radiator side of things, the higher flow rates push the water through the radiator tube much faster so it creates a much higher velocity in the cooling tubes. This higher water velocity actually creates more turbulence in the water, which rejects heat much better. So, that is why we say the old rule of thumb “slow down the water flow so it spends more time in the radiator in order to cool it better” is really not correct at all. The higher flow rate and higher water velocity through the radiator core really goes a long way in helping that radiator reject the heat.
What kind of performance Advantage will you see when you go to a higher flow rate?
The biggest performance advantage of the higher flow rate is keeping your temperatures in check and cooling your engine better. As far as any performance other than that, there really isn’t any. The critical part of a cooling system is the combustion chamber area in the cylinder heads. This is where the combustion is taking place and where the bulk of the heat is generated. We have seen higher flow rates help keep these combustion chambers cooler. It keeps the air from separating out of the water and causing local steam pockets and localized boiling in those combustion-chamber areas. It also keeps good water-to-metal contact in those areas, which is the secret to keeping everything cool.
What happens if those metal combustion chamber surfaces get too hot? The engine will actually get a mild detonation. With most race engines, if it starts overheating, the driver will come on the radio and say the car is starting to lose power, is running poorly and doesn’t have the horsepower he had before. What is happening is the temperature increases more and more and those hot spots in the cylinder heads will actually start creating a detonation situation in the engine—it is usually just a mild detonation, but it can make the power drop off.
What can an average racer do about controlling water speeds or flow rates? Is it just a matter of what type of water pump they install?
Yes, pretty much. The flow rate is not something racers can really control. Basically, you want the maximum water flow rate you can get. My suggestion is don’t worry about doing anything to physically control the flow. The engine itself is going to control flow rate because of the passages and the water system. It is only going to allow so much water to flow through because it only has so much area to work with. Winston Cup teams use AN line that goes from the engine back to the radiator. The hose size they pick can be somewhat of a restrictor. In other words, it could be the thing in the whole system that is restricting how much water is flowing throughout the whole system. If that is big enough that it is not the restrictor, well then, the radiator becomes the next restriction point.
Interesting topic, and I've always wondered if this is somehow related to the occasional ticker? The 'scrubbing' often discussed makes a lot of sense, and I've thought that maybe what the tickers have in common is too low of coolant flow around the exhaust valve guides. Obviously the non-tickers have the same coolant passages, so maybe this is a mute point.
Boysen makes higher capacity impellars for the coolant pumps on dirt bikes, with a claimed increase of as much as a 20% reduction in operating temps on some engines. The skeptic in me thinks that this is a no additional cost design decision at the OEM level, so why would the OEM impellar be undersized to begin with? However, if there is merit in this claim, maybe a higher flow impellar would be good for the FJR?
Just speculating, but I am curious.
:eh:
Boysen makes higher capacity impellars for the coolant pumps on dirt bikes, with a claimed increase of as much as a 20% reduction in operating temps on some engines. The skeptic in me thinks that this is a no additional cost design decision at the OEM level, so why would the OEM impellar be undersized to begin with? However, if there is merit in this claim, maybe a higher flow impellar would be good for the FJR?
Just speculating, but I am curious.
:eh:
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