Oil content in high temperatures
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Oil content in high temperatures
For experienced Zenoah GT80 and G62 users only, please.
I am running a GT80 and a G62 in hot weather, above 105 F (42 C). Using Klotz oil 50:1 now.
Would raising the oil content in high temperatures help keep them cooler? Possible negative effects?
Please comment if you have experience in this topic.
Thanks!
I am running a GT80 and a G62 in hot weather, above 105 F (42 C). Using Klotz oil 50:1 now.
Would raising the oil content in high temperatures help keep them cooler? Possible negative effects?
Please comment if you have experience in this topic.
Thanks!
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RE: Oil content in high temperatures
I've read somewhere that increasing the oil quantity in the mix will only raise the operating temperature. if anything enrichen the engine slightly or increase the octane of the fuel. Don't mess with the recommended oil to fuel mixture...
#3
RE: Oil content in high temperatures
Engine cooling is paramount compared to the oil type and quantity. Have the engine setup so its got baffling to direct the air across the engine to keep it as cool as possible and be done with it.
Gasoline doesn't behave anywhere like glow fuel where if you richen the mixture way up it cools the engine way down. There's a little of that effect with gas, but nowhere near as much as glow fuel.
Gasoline doesn't behave anywhere like glow fuel where if you richen the mixture way up it cools the engine way down. There's a little of that effect with gas, but nowhere near as much as glow fuel.
#4
RE: Oil content in high temperatures
I agree with 10wksport, arrange baffles that direct the air through the fins of the cylinder. If the head is not out in the air stream direct fresh air to pass through the fins of it.
Also be sure you have twice the size air exit hole as you do the air inlet . And I would leave the 50:1 mix alone.
Frank
Also be sure you have twice the size air exit hole as you do the air inlet . And I would leave the 50:1 mix alone.
Frank
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RE: Oil content in high temperatures
Twice the size does not matter; it's a myth that need not work. Yak cowls have HUGE air entries, yet are known for bad cooling without proper air ducting.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
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RE: Oil content in high temperatures
Pe, Guys,
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
#8
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RE: Oil content in high temperatures
ORIGINAL: Yak13
Pe, Guys,
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
Pe, Guys,
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
This isn't a glow situation where one may add several ounces of oil per gallon fuel to possibly improve cooling from more fuel volume through put
Put another way, it takes 12.8 ozs oil in 5 gallons gasoline to get 50:1 gasil mix. Increasing the oil 10% to 14.1 ozs per 5 gallons gas is what you are talking about (45:1 ratio).....That's a scant 1/4 oz per gallon increase which isn'tmuch added oil
#9
RE: Oil content in high temperatures
ORIGINAL: pe reivers
Twice the size does not matter; it's a myth that need not work. Yak cowls have HUGE air entries, yet are known for bad cooling without proper air ducting.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
Twice the size does not matter; it's a myth that need not work. Yak cowls have HUGE air entries, yet are known for bad cooling without proper air ducting.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
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RE: Oil content in high temperatures
ORIGINAL: captinjohn
pe reivers, How about profile airplanes where the engine has about total exposure to air. Is there a bad thing we should know about whats happens with them? Should a small air scoop be used to cool back-side of the cyl? Capt,n
ORIGINAL: pe reivers
Twice the size does not matter; it's a myth that need not work. Yak cowls have HUGE air entries, yet are known for bad cooling without proper air ducting.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
Twice the size does not matter; it's a myth that need not work. Yak cowls have HUGE air entries, yet are known for bad cooling without proper air ducting.
Be sure to have LOW PRESSURE at the cooling air exit. Block all air entry holes that do not direct air to the engine. You want none of that precious cooling medium to bypass the engine cooling fins.
I noticed a 30°C temperature drop in a fully exposed cylinder just by adding a cooling jacket.
Regarding oil content.
The oil very often burns off, and adds NOTHING to the cooling. In case the oil does not burn, there is about one ounce of oil going through the engine for half an hour of operation. Be sensible: how much heat will this thimble full of oil carry away???? The advantage is, that more oil lubricates better, and thus there is less friction to generate extra heat. This lack of friction (better=less friction) will make the engine run cooler.
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RE: Oil content in high temperatures
ORIGINAL: Yak13
Pe, Guys,
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
ing value
Pe, Guys,
The engine is properly cooled wth adequate airflow. My question is if raising the oil content to 45:1 actually helps cooling as many experienced pilots assure, or if will not do anything in this respect.
Thanks
ing value
Increasing the oil content in the fuel will do nothing for your engine temperatures. The percentage oil is small and the contact time is also very small meaning there is negligable additional heat transfer taking place due to oil. In total loss systems the biggest cooling factor is the air flow, secondly the stoichiometry of the engine and lastly the viscosity of the fluid in contact with the hot surface. If anything, adding more oil will result in more residdue build up on the piston and ring groove resulting in higher temperatures.
Changing the octane of the fuel will do nothing for your engine temperatures since octane is not heating value
You need to look at;
1) proper cooling baffles as mentioned above
2) ensure the engine is tuned correctly for the exhaust fitted
3) is not overloaded with too large a prop.
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RE: Oil content in high temperatures
here we go again.about the more oil and build up on the piston,not true in my case.i use redline at 32-1 and the top and sides of the piston are shinny new.