Spraying water into a hot engine

Tom-D said:
The Alison T-56-14 on the P-# Orion gets a full fresh water wash down in the taxi thru pits upon a return from every low level patrol. full stream down the intake nothing bothers it. TIT @ 1800C drops to about 5-600 then right back to 1800c
Click to expand...
Do you have any idea what happens to the Air in the compressor (which would also happen to the water)? After 14 stages of compression the air temp is approximately 600* F.
 
Last edited:
Tom-D said:
Have you ever seen how fast an turbocharged TSIO 540 cools when the outside air-temps are -40?
Part 135 operators operate these engines day in and day out cycle after cycle, with no problems. You pull power on a Navajo Chieftain and the CHTs will go down faster than the gauge can keep up.. Shock Cooling at it best, and never a problem of cracking.
Click to expand...

Yes I have.

2200 hours in Chieftains and I never cracked a cylinder. From my personal Alaska experience, one winter day I shut off a Chieftain at -42F, and as quickly as I could, I opened the rear stairs to let off one passenger, then back up front. Four minutes with the engines shut off. I could not start the engines because they were already cold soaked.

And that did not do any damage to the engines. But the company changed our minimum temperature operations to stop flying at -35F.
 
Clark1961 said:
Do you have any proof that the world is round?
Click to expand...

Funny but I've actually encountered someone who argued the world was flat because pilots don't have to constantly trim down to make up for the curvature.
 
gitmo234 said:
Funny but I've actually encountered someone who argued the world was flat because pilots don't have to constantly trim down to make up for the curvature.
Click to expand...
clearly conclusive...obviously you are ignoring facts so tom must be right. damn this stuff is easy....and here all along I thought tom was wrong because his arguments had no basis in physics...
 
4 minute cold soak? No way. -40 won't cool my engine like that. I can't get my preheater and cowl cover disconnected and stowed near that quickly for an engine barely heated by comparison. Mine starts every time.

I enjoy all the shock cooling comments. I watch my temps and they're over 300 when I shut down. The real shock comes after that, not to mention shock heating at startup and first application of full power.

I can't count how many times I've landed on floats and taxied downwind in waves with water splashing up and the prop soaking everything. No water problems. Not that I'd tempt fate with a garden hose.
 
Last edited:
Tom-D said:
So what can I tell ya? your easy on engines? others not so much, they still make TBO.
Click to expand...

What's you background at making nearly a mile a minute descents, over 10 times a day, nearly 7 days a week?
 
James331 said:
What's you background at making nearly a mile a minute descents, over 10 times a day, nearly 7 days a week?
Click to expand...
Don't take offense, every one can make TBO, it's just a matter of how much maintenance they do. OBTW lots of us were managing 4 radials for a long time, trying to get every minute of time they could from them. you only get to misuse a PRT once then you get to stay up all night replacing it to make the op next day.
 
GlennAB1 said:
Do you have any idea what happens to the Air in the compressor (which would also happen to the water)? After 14 stages of compression the air temp is approximately 600* F.
Click to expand...
yes, that doesn't matter here, the NAVY does it all the time, doesn't harm the engine at all, neither does a 250 degree drop in a recip. but it sure cleans the compressor.
we have received a low preforming T-56 from a squadron, taken it to the test cell, ran a wash cycle, then ran a hopper full of walnut shells thru the engine and the Performance will rise 5% so we simply return it to the squadron for reinstall.
washing engine is pretty routine with the navy, most every engine on the carriers will get at least 1 wash run during a cruise.
 
gitmo234 said:
It's actually Tom arguing against myself, Glenn, science, the FAA, and an engine service instruction. I wouldn't be surprised if the next post argues for us to prove the world is round
Click to expand...
Textron Lycoming Service Instruction 1049D, and FAA AC20-105B, 4. g.

Maybe Tom will actually get it if he reads it enough.
 
GlennAB1 said:
Argue with Textron Lycoming Service Instruction 1049D.
Click to expand...
So you bring up TBOs ?
Show me any instruction that says anything about the OP's case, show me any instruction you can't wash an engine, show every one any instruction saying one rapid cool down is reason to be concerned.
And that goes for Clark too.

there is nothing out there folks, these guys can be wrong, they will argue with any thing I post. but they at a loss for instructions to back any thing they contend.
 
GlennAB1 said:
Textron Lycoming Service Instruction 1049D, and FAA AC20-105B, 4. g.

Maybe Tom will actually get it if he reads it enough.
Click to expand...
Tom has had it many times. your whole contention is based upon this statement, taken out of context.
  1. The reliability and service life of engines can be detrimentally affected if they are repeatedly operated at alternating high and low power applications which cause extreme changes in cylinder temperatures. Flight maneuvers which cause engine overspeed also contribute to abnormal wear characteristics that tend to shorten engine life. These factors must be considered to establish TBO of aerobatic engines; therefore it is the responsibility of the operator to determine the percentage of time the engine is used for aerobatics and establish his own TBO. The maximum recommended is the time specified in this instruction.

    Because the OP's engine isn't considered as operating repeatedly at high and low temps. it was rapidly cooled once. and at a temp that is well below critical temp for aluminum.
 
Zeldman said:
Yes I have.

2200 hours in Chieftains and I never cracked a cylinder. From my personal Alaska experience, one winter day I shut off a Chieftain at -42F, and as quickly as I could, I opened the rear stairs to let off one passenger, then back up front. Four minutes with the engines shut off. I could not start the engines because they were already cold soaked.

And that did not do any damage to the engines. But the company changed our minimum temperature operations to stop flying at -35F.
Click to expand...
ATTA Boy,, thank you very much.
It's the cold starts that harm.
 
Tom-D said:
Tom has had it many times. your whole contention is based upon this statement, taken out of context.
  1. The reliability and service life of engines can be detrimentally affected if they are repeatedly operated at alternating high and low power applications which cause extreme changes in cylinder temperatures. Flight maneuvers which cause engine overspeed also contribute to abnormal wear characteristics that tend to shorten engine life. These factors must be considered to establish TBO of aerobatic engines; therefore it is the responsibility of the operator to determine the percentage of time the engine is used for aerobatics and establish his own TBO. The maximum recommended is the time specified in this instruction.

    Because the OP's engine isn't considered as operating repeatedly at high and low temps. it was rapidly cooled once. and at a temp that is well below critical temp for aluminum.
Click to expand...
My contention isnt based on that statement, at all.

According to Textron Lycoming Service Instruction 1049D "At all times, caution must be taken not to shock cool the cylinders. The maximum recommended temperature change should not exceed 50°F. per minute."

And, FAA AC20-105B, 4. g. - "all reciprocating engines are temperature sensitive. Engine cylinders and valves can be damaged by thermal shock if the engine is not properly warmed up, prior to full power applications, or the cylinder heads can crack by allowing the engine temperature to cool off too rapidly..."
 
Last edited:
Tom explain why the higher expansion rate is better, I can think of no reason.
 
Horse said:
Are you sure?.
Click to expand...

That's gotta be one of the funniest things I've ever read here and you'll likely never understand why because you won't hang around long enough to get to know people here.

Remain ignorant young man. It'll serve you well in life.
 
Stewartb said:
4 minute cold soak? No way. -40 won't cool my engine like that. I can't get my preheater and cowl cover disconnected and stowed near that quickly for an engine barely heated by comparison. Mine starts every time.

I enjoy all the shock cooling comments. I watch my temps and they're over 300 when I shut down. The real shock comes after that, not to mention shock heating at startup and first application of full power.

I can't count how many times I've landed on floats and taxied downwind in waves with water splashing up and the prop soaking everything. No water problems. Not that I'd tempt fate with a garden hose.
Click to expand...

Thank you, someone with the guts to buck the tradition and fight the dogma and say NO to ignorance and parroting of OWT's such as shock cooling.

In Zeldman's case there was likely a strong wind blowing at that -42F to cause such a rapid cool down. That -42F blast is no doubt way worse than any little garden hose could do.
 
Horse said:
Thank you, someone with the guts to buck the tradition and fight the dogma and say NO to ignorance and parroting of OWT's such as shock cooling.

In Zeldman's case there was likely a strong wind blowing at that -42F to cause such a rapid cool down. That -42F blast is no doubt way worse than any little garden hose could do.
Click to expand...

Actually water will cool much quicker than air, that's why they call it quenching.

You still don't get it, making up your own procedures, like cooling an engine with a water hose, is going to kill you eventually, you'be been told, troll on.
 
Tom-D said:
Don't take offense, every one can make TBO, it's just a matter of how much maintenance they do. OBTW lots of us were managing 4 radials for a long time, trying to get every minute of time they could from them. you only get to misuse a PRT once then you get to stay up all night replacing it to make the op next day.
Click to expand...

Perhaps I should have said made TBO without replacing jugs.
 
timwinters said:
No way. If Bryan were to troll, he'd do it in a smartassed fun way. Not an "I'm ignorant but I still know it all" way.
Click to expand...

Hmm... the "I'm ignorant but still know it all" sounds like a certain a-hole I finally had the displeasure of meeting in the FB group Bryan started. Agree that this isn't Bryan.
 
Last edited:
Yup, I used to put threads on ignore once they passed 50 posts. Got out of that habit. Might have to start again.
 
Oh PLEASE don't put this thread on ignore! That would just DEVASTATE me!

LOL. Got to love people who feel the need to let you know they're going to ignore you. Maybe I should have called myself Dog then the Man who prefers DOGS to people might be lovin' on me instead. How those gold plated cylinders by the way?

So this is no laughing matter. This is not meant to be a joke for your enjoyment. This is a serious discussion and plenty of other posters here have either agreed with me or half agreed with me so I'm not as nuts as you say.

Feel free to ignore it really is quite easy.

:rolleyes:
 
Horse said:
Oh PLEASE don't put this thread on ignore! That would just DEVASTATE me!

LOL. Got to love people who feel the need to let you know they're going to ignore you. Maybe I should have called myself Dog then the Man who prefers DOGS to people might be lovin' on me instead. How those gold plated cylinders by the way?

So this is no laughing matter. This is not meant to be a joke for your enjoyment. This is a serious discussion and plenty of other posters here have either agreed with me or half agreed with me so I'm not as nuts as you say.

Feel free to ignore it really is quite easy.

:rolleyes:
Click to expand...

Dude, I sincerely hope this is a joke, or you're just trolling, if this is your real attitude, and you're really a student pilot, you're screwed, and may god have mercy on any pax you might one day have... presuming you can find a CFI and DPE who will ever let you progress that far.
 
Horse said:
This is not meant to be a joke for your enjoyment.
:rolleyes:
Click to expand...
My guess is that it was meant to be a joke for YOUR enjoyment, and you did get the usual suspects to argue in a maintenance thread. But that doesn't take much skill. Asking any question related to maintenance suffices.
 
yup....:D

65862859.jpg
 
GlennAB1 said:
My contention isnt based on that statement, at all.

According to Textron Lycoming Service Instruction 1049D "At all times, caution must be taken not to shock cool the cylinders. The maximum recommended temperature change should not exceed 50°F. per minute."

And, FAA AC20-105B, 4. g. - "all reciprocating engines are temperature sensitive. Engine cylinders and valves can be damaged by thermal shock if the engine is not properly warmed up, prior to full power applications, or the cylinder heads can crack by allowing the engine temperature to cool off too rapidly..."
Click to expand...
You may have a point if shock cooling had occurred. It didn't.
the shock cooling controversy being what it is has never been proven to be any thing but a CYA for the manufactures.
have you ever seen how fast an engine can cool when feathered ? how many crack when that is done?
Operators in Alaska during the winter ops exceed these parameters nearly every shut down, they don't suffer the problems of shock cooling.
hen engine operators continually use bad practices, they will suffer shorter engine life. That requires a trend, one shot isn't a trend.
 
timwinters said:
Yup, I used to put threads on ignore once they passed 50 posts. Got out of that habit. Might have to start again.
Click to expand...
Another typical post from Tim, adds nothing to the thread.
 
GlennAB1 said:
No joke, the engine was possibly damaged, do you just ignore that possibility and the possible IFE that could have been prevented?
Click to expand...

Yes the engine was possibly damaged but not likely. It's possible you're a donkey with amazing typing skills but also not likely.
 
I have run into Horses before. They sometimes get asked to leave a flight school well before they're done, and they certainly never get to rent an airplane from anyone that knows them. The risks just aren't worth it. The attitude goes far beyond washing an engine down with cold water; it extends to violating regulations and school policies and taking serious chances with the airplane.

The Five Hazardous Attitudes. Look it up. See what Anti-Authority is all about. The dismissing of a CFI's opinions that conflict with a greenhorn's--even the opinions of a CFI that might not know much about engines--is one of the symptoms.
 
So you advocating never questioning a CFI?
 
You must log in or register to reply here.
Back
Top