Jake experts?

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pmanton

pmanton

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N1431A
I'm not a round engine guy, but I'm starting to get involved in a C-195 here at the airpark.

The plane was not flown for 6 weeks and enough oil drained into the bottom cylinders to wind up in the intakes.

He was told to remove a plug from the bottom cylinders and run the engine to get rid of the oil.

Isn't there a check valve in the oil pump that should have prevented this?

There is a "clean kit" installed on the engine if this has a bearing.

Thanks

Paul
N1431A
N83803
2AZ1
 
No, what you describe is not uncommon.

There's actually a set of videos (DVD) on the Jake engines. My buddy with a WACO has them and I watched some of them with him.

Shoot me your email in a PM and I'll forward his contact info to you.
 
pmanton said:
I'm not a round engine guy, but I'm starting to get involved in a C-195 here at the airpark.

The plane was not flown for 6 weeks and enough oil drained into the bottom cylinders to wind up in the intakes.

He was told to remove a plug from the bottom cylinders and run the engine to get rid of the oil.

Isn't there a check valve in the oil pump that should have prevented this?

There is a "clean kit" installed on the engine if this has a bearing.

Thanks

Paul
N1431A
N83803
2AZ1
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I'm no expert, but I'd say that pulling a plug and turning it by hand is probably smarter. The C195 video I watched had the guy pulling the prop through 7 compression "events" as part of every preflight.
 
I missed that in the first post. Pull the plugs and then move the prop through by hand...running the engine isn't likely to be too useful
 
Paging Mr. Greg Bockleman, please come to an Airport Information Booth or a white paging telephone... ;)
 
The plane was not flown for 6 weeks and enough oil drained into the bottom cylinders to wind up in the intakes.

He was told to remove a plug from the bottom cylinders and run the engine to get rid of the oil.

Isn't there a check valve in the oil pump that should have prevented this?
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There's nowhere to put such a valve. The design of the engine means that oil will often end up in the bottom cylinders.

Pulling the engine through by hand is often the wrong choice, depending on the engine. In many cases, it's safer to use the starter motor, because if there's a hydraulic lock, the starter clutch will slip, protecting the engine. One can do damage on some engines when pulling through by hand.
 
Pulling it through by hand with the plugs in is not to way to detect or clear hydraulic lock. You won't get lock with the plugs out (and that is the only way to clear it).

I'm not sure I'd trust the clutch to avoid the lock either and god help you if it manages to fire a cylinder before the bottom one reaches it's compression stroke (make sure BOTH ignitions are off).
 
Why would pulling the engine through with the starter cause the engine to fire? It won't.

It's certainly no different in that respect than pulling it though by hand.

In starter motors equipped with a clutch, protection of the engine is much better than using the long arm of the propeller a lever to turn it through by hand.

Radial engines are always pulled through before adding fuel and spark.
 
Never said it would, but suggested you better make sure given the original suggestion to RUN the engine.

DouglasBader said:
W
Radial engines are always pulled through before adding fuel and spark.
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Pulling it "through" is not the answer. One would hope that if you had hydraulic lock, you'd detect it (either because you were being careful when moving the prop by hand or hoping the starter won't break things before it disengages).
 
I don't know anything about radials. That said, I just saw an episode of "Ice Pilots" where they were getting a DC-4 ready for a trip. It had been sitting for about a month and they pulled the bottom plugs and ran the engines for a little while to clear the oil.
 
Pulling it "through" is not the answer. One would hope that if you had hydraulic lock, you'd detect it (either because you were being careful when moving the prop by hand or hoping the starter won't break things before it disengages).
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Got any radial engine experience?

I do.

Pulling it through it the requirement, and the answer. Yes, you check for hydraulic lock by pulling it through, and on many engines, that's with the starter, because it isn't nearly as easy to feel on a long propeller lever arm, and one can bend a rod doing it by hand. Not so with the starter.

Where a starter employs a clutch, it's far safer to use that starter motor to pull the propeller through.

As one who fly radial powered aircraft for a living, always on an active alert, we didn't go pull anything though by hand while responding; we turned it through by the starter, the requisite number of blades, before applying spark, and fuel.

That said, I just saw an episode of "Ice Pilots" where they were getting a DC-4 ready for a trip. It had been sitting for about a month and they pulled the bottom plugs and ran the engines for a little while to clear the oil.
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Pulling the plugs and motoring the engine with the starter after the cylinders have drained is one thing. Running the engine is entirely different, and one doesn't run the engine with the spark plugs out. Motoring it through with the starter is acceptable.
 
pulling the radials thru with the starter is really really really stupid. the rotation group will carry enough inertia energy to bend a rod.

never rotate the hydraulic locked cylinder backwards to clear the oil from the cylinder. that only places the oil in the intake and then it will be sucked into the cylinder on the next intake event.

get a big drip pan, pull the plugs, and the rocker box covers from all the lower cylinders and catch the oil. when it quits dripping put every thing back and start the engine normally.

the check valve that prevents the oil from running back to the engine is incorporated in the oil pump. It is a normal looking ball check, that works in reverse, it is spring loaded shut, keeping the oil in the tank until the oil pump sucks it open. and yes they need to be cleaned regularly.

I've owned and operated radials most of my life and now own a Warner 165 that I have rebuilt from the master rod to the top end. I regularly maintain the P&W965 on the beavers and the P&W1340 on the Otters. and have worked several facilities that reworked the 3350s and 2800s plus the 4360.

pull the prop thru by hand carefully, you'll feel the hard to pull area.

all radials do not have a clutch in the starter and all radials do not have problems with oil leaking into the cylinders by running down thru the cylinder, most flood the cylinders by drain down entering the push rod tubes, in the cam ring chamber, then flooding the rocker boxes then leaking by the valve guides and filling the exhaust and or the intake valve ports.
 
DouglasBader said:
Got any radial engine experience?

I do.
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YES and a hell of a lot more than you do.

and judging by what you are telling here, you have never had any of the engines apart , or know what a reverse flow check valve is.
 
pulling the radials thru with the starter is really really really stupid. the rotation group will carry enough inertia energy to bend a rod.
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No, it's not, and it was standard procedure for us on the R2800's, R2600's, R3350's, and R4360's.

Bump the starter. If it doesn't move and the clutch slips, there's hydraulic lock.

Pull a 4360 through by hand and you stand a very good chance of doing internal damage.

all radials do not have a clutch in the starter and all radials do not have problems with oil leaking into the cylinders by running down thru the cylinder, most flood the cylinders by drain down entering the push rod tubes, in the cam ring chamber, then flooding the rocker boxes then leaking by the valve guides and filling the exhaust and or the intake valve ports.
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Your statement is wrong. By saying "all radials do not" you make the statement that no radials do have a clutch in the starter. This is not true.

Not all radial engines use starter motors with a clutch.

Some radial installations use starter clutches, which is why I made the statement that I did, that in aircraft which use clutch-equipped starters, the starter should be used.

the check valve that prevents the oil from running back to the engine is incorporated in the oil pump. It is a normal looking ball check, that works in reverse, it is spring loaded shut, keeping the oil in the tank until the oil pump sucks it open. and yes they need to be cleaned regularly.
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Which doesn't prevent oil from entering the cylinders through the pushrod tubes, valve guides, and valves.

and judging by what you are telling here, you have never had any of the engines apart , or know what a reverse flow check valve is.
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I surely have had them apart, from the R985 through the R4360, and have been a mechanic, inspector, pilot, and instructor in aircraft equipped with radial engines, from ag operations to aerial firefighting, and I'm presently maintaining radial engine powered aircraft.

A reverse flow check valve is used in a number of installations, but does not prevent hydraulic lock, nor do crossflow tubes or other various methods and gimmicks and features that have been used to try to avoid what is common to radial engines...oil pooling in the lower cylinders.

YES and a hell of a lot more than you do.
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That's nice. Another engine-related dick measuring contest, is it?
 
denverpilot said:
Paging Mr. Greg Bockleman, please come to an Airport Information Booth or a white paging telephone... ;)
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Tom is a round engine guy and what he posted is accurate.

Those of us that have been around here long enough know Tom's posting style well enough to know what Tom meant by his statement, grammar notwithstanding. Doug needs to give it a rest.
 
Greg Bockelman said:
Tom is a round engine guy and what he posted is accurate.

Those of us that have been around here long enough know Tom's posting style well enough to know what Tom meant by his statement, grammar notwithstanding. Doug needs to give it a rest.
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I read this aloud in my best Greg voice to Karen and she started giggling on the couch. Haha.
 
DouglasBader said:
No, it's not, and it was standard procedure for us on the R2800's, R2600's, R3350's, and R4360's.

Bump the starter. If it doesn't move and the clutch slips, there's hydraulic lock.

Pull a 4360 through by hand and you stand a very good chance of doing internal damage.

What ever .. it's pretty easy to give bad advise when you have no skin in the game.


Your statement is wrong. By saying "all radials do not" you make the statement that no radials do have a clutch in the starter. This is not true.

Not all radial engines use starter motors with a clutch.

Some radial installations use starter clutches, which is why I made the statement that I did, that in aircraft which use clutch-equipped starters, the starter should be used.



Which doesn't prevent oil from entering the cylinders through the pushrod tubes, valve guides, and valves.



I surely have had them apart, from the R985 through the R4360, and have been a mechanic, inspector, pilot, and instructor in aircraft equipped with radial engines, from ag operations to aerial firefighting, and I'm presently maintaining radial engine powered aircraft.

A reverse flow check valve is used in a number of installations, but does not prevent hydraulic lock, nor do crossflow tubes or other various methods and gimmicks and features that have been used to try to avoid what is common to radial engines...oil pooling in the lower cylinders.



That's nice. Another engine-related dick measuring contest, is it?
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What ever .. it's pretty easy to give bad advise when you have no skin in the game.

you give this advice when you don't have a clue which starter he has on the JAKE.

In the NAVY heavy squadrons had you cranked any large radial with the starter before you did a proper pre-flight and checked for oil in the lower cylinders your Master chief wold have very unceremoniously kicked your butt.
 
DouglasBader said:
A reverse flow check valve is used in a number of installations, but does not prevent hydraulic lock, nor do crossflow tubes or other various methods and gimmicks and features that have been used to try to avoid what is common to radial engines...oil pooling in the lower cylinders.
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The reason the check valve can't stop the oil from entering the combustion chamber is quite easy to explain, it can't because that is not where the oil comes from.
 
For those who are still trying to understand.

Oil that has not been scavenged by the scavenge pump. will drain down into the lower cylinder rocker boxes that contain the valve springs, keepers, and guides, it will then leak thru the valve guides and enter the cylinder thru an open valve.

when you rotate the crank any cylinder with an open intake valve will close that valve and trap the oil in the cylinder on compression stroke. that is known as a hydraulic lock. the cylinder has both valves closed, the piston is on its way up. and hits a solid mass, the weakest link (the rod) will then bend.

When a connecting rod is bent the effective length of it will be shorter and as the piston is pushed past the oil, it will then be pulled down the cylinder too far and the counter weights will then smash the piston as the crank comes around.

see the pictures below, and note how little clearance there is between the counter balance weights and the piston skirt.

and see the cam ring compartment and note that the lower cylinder pushs rod tubes run down to the rocker boxes.
 

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In the NAVY heavy squadrons had you cranked any large radial with the starter before you did a proper pre-flight and checked for oil in the lower cylinders your Master chief wold have very unceremoniously kicked your butt.
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That's nice.

I flew PB4Y-2's and P2V-7's, and had we pulled either of those through by hand rather than with the starter, we'd have been in a boat load of trouble, no master chief involved.

The reason the check valve can't stop the oil from entering the combustion chamber is quite easy to explain, it can't because that is not where the oil comes from.
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I know that. I said that.
 
Didn't mean to start a war. :)

The owner was taught to pull the prop through by hand by the people who checked him out. When he did he heard a "gurgling" sound when the lower cylinders came up on compression. He called me to come listen. (I do the maint. & annuals on his other planes)

I told him that it wasn't right but I didn't know enough about the engine to advise him. He then called a round engine "guru" who advised him that the only way to get all the oil out was to pull a plug on the lower cylinders and run the engine.

He did and lots of oil came out and made a big mess.

So if the oil is getting there via the push rod tubes then it's a design defect ? Will he have the lower cylinders fill up anytime the engine isn't flown for a few weeks?

Could a dirty check valve be the culprit?

I installed an STC oil filter setup he got from the 195 club. The oil should be nice and clean by now.

I guess I should look for a book "Round engines for dummies"

Thanks

Paul
N1431A
N83803
2AZ1
 
pmanton said:
I told him that it wasn't right but I didn't know enough about the engine to advise him. He then called a round engine "guru" who advised him that the only way to get all the oil out was to pull a plug on the lower cylinders and run the engine.

Proper advice.OBTW... don't "RUN" the engine with the plugs out.. unless you would like to paint the ramp and every thing with 50' with 65 weight oil./B]

So if the oil is getting there via the push rod tubes then it's a design defect ?

Not a design as much as it is a lack of scavenging or a worn scavenge pump.



Will he have the lower cylinders fill up anytime the engine isn't flown for a few weeks?

If it did it once, what's to stop it from doing it again?

Could a dirty check valve be the culprit?

Yes, the way to cure it will be to pull the oil pump and clean it in a carb cleaner and inspect it very well to see if the scavenge pump side is worn.

I installed an STC oil filter setup he got from the 195 club. The oil should be nice and clean by now.

That's a good mod, but you should also install a clean kit. http://clean-kit.com/3.html
I guess I should look for a book "Round engines for dummies"

Thanks

Paul
N1431A
N83803
2AZ1
Click to expand...


Look around and see if you can find the MM for the Jake. very good study for the radial mechanic.
What oil is he running?
 
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So if the oil is getting there via the push rod tubes then it's a design defect ? Will he have the lower cylinders fill up anytime the engine isn't flown for a few weeks?
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It's not a design defect; it's the nature of round engines.

Some would have you believe that hydraulic lock occurs if the airplane sits long enough; that's not true. I've awakened engines the that have been sitting for 30 to 40 years, without any evidence of hydraulic lock, and I've operated engines for several years before experiencing one. On the other hand, I've seen some that liquid lock not long after shutdown. Recent operation is no guarantee, either.

Various fixes or features have been created or tried to help eliminate hydraulic lock, or to reduce it's frequency, but thus far, it's still just the nature of the beast.
 
DouglasBader said:
It's not a design defect; it's the nature of round engines.

Some would have you believe that hydraulic lock occurs if the airplane sits long enough; that's not true. I've awakened engines the that have been sitting for 30 to 40 years, without any evidence of hydraulic lock, and I've operated engines for several years before experiencing one. On the other hand, I've seen some that liquid lock not long after shutdown. Recent operation is no guarantee, either.

Various fixes or features have been created or tried to help eliminate hydraulic lock, or to reduce it's frequency, but thus far, it's still just the nature of the beast.
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When your engine has a leak, internal or external you should get it fixed.
 
You could always replace it with turbines, but the fact is, radial engines hydraulic lock.

I've had many that didn't do it often, but eventually they do. Others do it all the time. Some engine types more than others.

Don't want hydraulic lock and the other things associated with radials? Replace it with turbines.
 
DouglasBader said:
You could always replace it with turbines, but the fact is, radial engines hydraulic lock.

I've had many that didn't do it often, but eventually they do. Others do it all the time. Some engine types more than others.

Don't want hydraulic lock and the other things associated with radials? Replace it with turbines.
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That advice is really going to help the OP with the C-195.
 
Wow. Panelists, I think we have yet another "always right" here.....
I'd think the correct answer would be closer to "it depends..." but what we got was, "and I do...."

And now we've got "and I still do...."

Hey give it a rest.......
 
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As the bartender said,
"It's going to be a long night. The Murphy twins are drunk again."

bbchien said:
Wow. Panelists, I think we have yet another "always right" here.....
I'd think the correct answer would be closer to "it depends..." but what we got was, "and I do...."

And now we've got "and I still do...."

Hey give it a rest.......
Click to expand...
 
DouglasBader said:
Your contribution to the subject of radial engines is exactly what, here?
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Yer talkin' to the wrong Doc, Master Bader! You should see out a proctologist to help get that bug outta yer butt. Doc Chien just does aeromedical stuff.
 
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You too. Both of you whining about people contributing to the thread, and neither of you anything more to contribute than to complain about another poster. Gooses and their gander.

I do have radial engine experience as a pilot, mechanic, and inspector, on a lot of different radial engines, and work on them currently. My commentary is correct, and accurate. It is germane to the topic of radial engines.

Yours? Not at all. None the less, you whine about my contribution, as always. Thanks for playing.
 
DouglasBader said:
You too. Both of you whining about people contributing to the thread, and neither of you anything more to contribute than to complain about another poster. Gooses and their gander.

I do have radial engine experience as a pilot, mechanic, and inspector, on a lot of different radial engines, and work on them currently. My commentary is correct, and accurate. It is germane to the topic of radial engines.

Yours? Not at all. None the less, you whine about my contribution, as always. Thanks for playing.
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Midol might help you...maybe you should be seeing several medical specialists...
 
Another brilliant contribution regarding radial engines. Well done.
 
DouglasBader said:
Pulling the engine through by hand is often the wrong choice, depending on the engine. In many cases, it's safer to use the starter motor, because if there's a hydraulic lock, the starter clutch will slip, protecting the engine.
Click to expand...
Would this be the case for the R-755?
 
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