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cht on aircraft motor

M

mwood7800

Well-known member
I remember seeing it posted but couldn't find it, what cylinder temp should I shut mine off at if reached?
 
i've been waiting on a reply for this. i've got an io520 temps usually run 400-425 but continetal says 375-400 i wonder if i'm hurting my engine
 
Airboats are always going to run higher temps than aircraft. Airboats are running close to sea level, aircraft don't.

Do a search for CHT, you'll find other threads in this forum about it
 
Hey Red,

Please explain how the airplane gets off the ground. I always thought it produced max power only at takeoff.

Jim
 
OK, so maybe not ALWAYS, but how long does it take for an airplane to get off the ground?

How long might it take for an airboat to get off the ground?

And to answer your question, the airplane gets off the ground by producing more air pressure under the wing than it has above it, or "lift" as I like to call it :wink:
 
So I guess the next logical question would be....what kind of CHT does he run?
 
I was always told the following:

Every 1000 feet drops temperature a few degrees, so just a little altitude helps the engine attitude by increasing cooling.

Air flow in the air is at a minimum about 60 mph up to about 120 plus mph versus probably about 30 on land (water). Much less cooling from airflow due to less speed.

Maximum oxygen levels are at sea level and that supposedly helps make complete combustion at sea level and produces more heat.

How much is true, I don't know.

Then you get into the arguement of running peak of lean in the air versus typically full rich on the ground (which makes it run cooler).

But around 375 to 400 degrees is typically what TIO-360s run on a twin engine plane a friend operates.
 
THANKS CRACKER I was told this was normal for an a/c motor by the builder but i always like aditional input
 
Any motor that burns gasoline must maintain a specific air to fuel ratio to produce the most power and to be the most efficient. The lower the altitude the more oxygen is present in the air. Any serious racing compietor checks the corrected altitude for where they are racing then jets their car to run optimum to the oxygen that a present in the air. Here it is plain and simple the lower you are the more oxygen is present in the air so the more power you can make. Cooler air also contains more oxygen but when you increase altitude it doesn’t compensate enough to over come the lower oxygen levels that come with a higher altitude. So any racers dream is a cold day at low altitude like in Florida or Texas. That why all the NHRA World Records in the normally aspirated classes like Pro Stock, Comp Eliminator and Super Stock have all been set at Gainesville or Texas because these are the too lowest tracks in the NHRA series.
 
I couldn't agree more thunder you don't see many records set in places like colorado and i also understand jetting to be very critical in aircooled motors as the fuel does some of the cooling i try to aim for a 12 to 1 air fuel ratio even though i don't get the economy i get a cooler running engine that lasts longer my experience with volkswagen engines has proved this many times over and the similarities between these two engines is what draws me to the a/c engine
 
An efficient air-cooled motor now there is an oxymoron. Just teasing you aircraft guy’s----If you have extensive knowledge of Volkswagen motors that you defiantly know how to handle an aircraft motor.
 
scooter,

Lycon engines in Visalia CA builds a lot of stock and highly modified aircraft motors. They are an approved overhaul station for Continental and Lycoming I believe. If you want some specific advice about max head temps you should e-mail them at lycon@lycon.com. Tell them what engine you have and if you have steel, nitrided, or chrome cylinders and they can then advise you what they feel is the max head temp allowed. You should also tell them that the engine is on an airboat and is out in the open (unshrouded). Let me know what they say.

They like to run their hotrod motors at 150 degrees rich from peak egt for extra cooling..

Jim
 
Red,

I'll ask him the next time I see him if you need to know. My point was that aircraft engines are designed to produce maximum power at the takeoff altitude which may be above or below sea level depending on where you are. The higher they go, the weaker they get because the atmospheric pressure declines with gains in altitude. At 10,000 feet a normally aspirated aircraft engine is cuuised at full throttle and still does not produce full cruise power much less rated power. There are many applications where they are operated at low altitude such as airshows, air racing, cropdusting, banner towing, and just plain flat-hatting.

Jim
 
Waterthunder":2acztvri said:
Gainesville......
Click to expand...

Yeah, we got a SWEET track and I'm proud to work there! 8)

cracker":2acztvri said:
The higher they go, the weaker they get because the atmospheric pressure declines with gains in altitude
Click to expand...

And as they "get weaker" they are putting out less heat anyways. That was my original point. My premise was that Continental's numbers would be somewhat shy of what you might see in a typical airboat.
 
Red,

The flat opposed aircraft engines do not cool well when mounted "in the open" with no cowling either in a boat or in an airplane. If you operate one at high power and no cooling air directed through the cooling fins, it may overheat. A rich mixture helps.

The reason the airplanes cool better even at sea level is that they have pressure cowlings and the airspeed to make them work. The Volkwagon had the same.

I was watching 30 seconds over Tokyo today (I am old enough to remember WW2). They flew those B25's about 600 miles right down on the water. The airplane is very effenient in ground effect or "T" effect as it is called over water. The low altitude decreases the drag and increases the lift.

Jim
 
CRACKER i've heard guy's talk about cowlings for airboats but i have never seen one. do they work and if so were can i get one and why doesn't everybody have the on there boats.
 
Thanks Cracker now for my next question who's mark ? and how can i contact him. didn't think you would be on this weekend figured you would be at the hill.
 
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