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Anyone have any clues as to why the coolant would be leaving the cooling system via the overflow tube and bottle?The engine does not overheat even after 1-2 hours flying but when I land there is coolant all over the motor and tail and the bottle is full. Shut the motor off and the bottle drains back into the radiator but then need a half litre or so to top up. Its as if it is building up too much pressure?Have replaced the radiator cap and thermostat. Could the cap be the wrong pressure rating?Thanks in advanceMC
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Water expands the more you have the more that will be displaced this is a common problem on gyros as people try to have no air in the system if it is posable lift the cap section up on a longer bit of hose this alows the displaced water to be above the therostat & cause no ill effects & there will be no need to top up as the overflow bottle will be enoughButch S.
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Water expands the more you have the more that will be displaced this is a common problem on gyros as people try to have no air in the system if it is posable lift the cap section up on a longer bit of hose this alows the displaced water to be above the therostat & cause no ill effects & there will be no need to top up as the overflow bottle will be enoughButch S.
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Water expands the more you have the more that will be displaced this is a common problem on gyros as people try to have no air in the system if it is posable lift the cap section up on a longer bit of hose this alows the displaced water to be above the therostat & cause no ill effects & there will be no need to top up as the overflow bottle will be enoughButch S.
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Mark,My solution would be an overflow bottle of another 750 ml on top of what you already have, and I'd use Stephen's trick too as the air will compress instead of water spilling out of the cooling system. Mine was doing this before I put the big radiator on, after it would only spit a little out after you stopped the engine.For my new radiator the cap pressure was at 0.8~0.9 bar or near 12 psi.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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Mark,My solution would be an overflow bottle of another 750 ml on top of what you already have, and I'd use Stephen's trick too as the air will compress instead of water spilling out of the cooling system. Mine was doing this before I put the big radiator on, after it would only spit a little out after you stopped the engine.For my new radiator the cap pressure was at 0.8~0.9 bar or near 12 psi.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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Mark,My solution would be an overflow bottle of another 750 ml on top of what you already have, and I'd use Stephen's trick too as the air will compress instead of water spilling out of the cooling system. Mine was doing this before I put the big radiator on, after it would only spit a little out after you stopped the engine.For my new radiator the cap pressure was at 0.8~0.9 bar or near 12 psi.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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I,ll try that, many thanks.The system has worked fine for years though and only started this trick since fitting a different motor.MC
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I,ll try that, many thanks.The system has worked fine for years though and only started this trick since fitting a different motor.MC
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I,ll try that, many thanks.The system has worked fine for years though and only started this trick since fitting a different motor.MC
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I forgot to add:You should do a cooling system pressure test to see if there are any leaks in it, and;A spark plug pressure test without the radiator cap on [put compressed air into the cylinder at 100 psi at top dead centre on each pot - use a spark plug to compressed air adapter for this to pressurise each cylinder - one at a time - lock the prop up as it could kick] if you get bubbles coming through the cooling system this could mean you have a head gasket failure where combustion gases are forced into the cooling system and these then displace the water, this can cause overheating and loss of coolant which in turn results in engine loss of power and ultimate seizure.Stephen's idea allows these gases 'if' they come into the cooling system to collect in the extra hose and discharge without taking the water out of the system, as does the overflow bottle which only works when the system cools down and the water is sucked back into the cooling system.Another way to do this test is to squeeze a funnel into the neck of the radiator fill point so it has a tight seal, fill it with water and run the engine until warm, be careful of the prop and just observe whether the expansion of the water stops when the engine achieves its operating temperature, also look for a continual effluvium of gases from the funnel via the water, this would lead me to believe there was a head gasket problem, *do not rev the engine* whilst doing this as pressure fluctuations from the cooling pump with extra revs will give you a misleading ebb and flow of water in the funnel.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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I forgot to add:You should do a cooling system pressure test to see if there are any leaks in it, and;A spark plug pressure test without the radiator cap on [put compressed air into the cylinder at 100 psi at top dead centre on each pot - use a spark plug to compressed air adapter for this to pressurise each cylinder - one at a time - lock the prop up as it could kick] if you get bubbles coming through the cooling system this could mean you have a head gasket failure where combustion gases are forced into the cooling system and these then displace the water, this can cause overheating and loss of coolant which in turn results in engine loss of power and ultimate seizure.Stephen's idea allows these gases 'if' they come into the cooling system to collect in the extra hose and discharge without taking the water out of the system, as does the overflow bottle which only works when the system cools down and the water is sucked back into the cooling system.Another way to do this test is to squeeze a funnel into the neck of the radiator fill point so it has a tight seal, fill it with water and run the engine until warm, be careful of the prop and just observe whether the expansion of the water stops when the engine achieves its operating temperature, also look for a continual effluvium of gases from the funnel via the water, this would lead me to believe there was a head gasket problem, *do not rev the engine* whilst doing this as pressure fluctuations from the cooling pump with extra revs will give you a misleading ebb and flow of water in the funnel.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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I forgot to add:You should do a cooling system pressure test to see if there are any leaks in it, and;A spark plug pressure test without the radiator cap on [put compressed air into the cylinder at 100 psi at top dead centre on each pot - use a spark plug to compressed air adapter for this to pressurise each cylinder - one at a time - lock the prop up as it could kick] if you get bubbles coming through the cooling system this could mean you have a head gasket failure where combustion gases are forced into the cooling system and these then displace the water, this can cause overheating and loss of coolant which in turn results in engine loss of power and ultimate seizure.Stephen's idea allows these gases 'if' they come into the cooling system to collect in the extra hose and discharge without taking the water out of the system, as does the overflow bottle which only works when the system cools down and the water is sucked back into the cooling system.Another way to do this test is to squeeze a funnel into the neck of the radiator fill point so it has a tight seal, fill it with water and run the engine until warm, be careful of the prop and just observe whether the expansion of the water stops when the engine achieves its operating temperature, also look for a continual effluvium of gases from the funnel via the water, this would lead me to believe there was a head gasket problem, *do not rev the engine* whilst doing this as pressure fluctuations from the cooling pump with extra revs will give you a misleading ebb and flow of water in the funnel.Hope this helps,Nicholas TomlinAlarmist - www.alarmist.com.au - we scare for you
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Have you pulled the head down with a tension wrench? Have you had the coolant checked for products of combustion? Cracked heads are fairly common and often quite servicable as they often don't leak, perhaps yours does.John EvansThink logically and do things well, think laterally and do things better.
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Have you pulled the head down with a tension wrench? Have you had the coolant checked for products of combustion? Cracked heads are fairly common and often quite servicable as they often don't leak, perhaps yours does.John EvansThink logically and do things well, think laterally and do things better.
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