Exhaust leaks

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
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Dave Taylor
I was thinking I could put a balloon over the exhaust stack as a visual indication of exhaust valve leaks - but I think what would happen is the leaking air would simply go into an adjacent exhaust valve & out an intake, or leak through an exhaust slip joint.
So we are left with someone holding the prop while someone else listens at an exhaust stack.

I'd like to come up with a way to verify the exhaust valve leak, and to quantify it.

I know, on poa somebody says why or no need or dont do that; cmon how about offering ideas instead, this time? :)
 
Let'sgoflying! said:
I was thinking I could put a balloon over the exhaust stack as a visual indication of exhaust valve leaks - but I think what would happen is the leaking air would simply go into an adjacent exhaust valve & out an intake, or leak through an exhaust slip joint.
So we are left with someone holding the prop while someone else listens at an exhaust stack.

I'd like to come up with a way to verify the exhaust valve leak, and to quantify it.

I know, on poa somebody says why or no need or dont do that; cmon how about offering ideas instead, this time? :)
Click to expand...
No need to come up with a different method so why would you want to do so?

Did that cover the POA negativity for you?
 
Thanks for helping get that out of the way with, Clark. Here let me add a few.
You don't need that
We don't do it that way
That's the wrong way
Why would you bother with
What could possibly be learned from
What possible benefit is there from

Whew now that this is out of the way, let's put noggins together and address the Q!
 
Too late, my noggin dun came from together...
 
E valve leaks? Pressurize the cylinder for a compression test and listen for a leak. Pretty simple. Why try to make it hard?
 
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Here's what an exhaust leak looks like.
 

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Let'sgoflying! said:
I know, on poa somebody says why or no need or dont do that; cmon how about offering ideas instead, this time?
Click to expand...

Edit: reread post. For an exhaust valve leak the only way I know is do a compression test, and as you said listen at the exhaust.
 
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Stewartb said:
and listen for a leak
Click to expand...

Lets say the person listening does not have great hearing. Sometimes when even I do it, I hear hissing but am not 100% sure where it is coming from until I spend some time investigating.
A visual indication would be a plus.

Think of it like how the digital inclinometer (which I started using to time mags in the last few years) is way better than the old 'cone' method.
I am always looking for something better and not always happy with the status quo.
PS I'll get back to you about the door closer shortly. Thanks.
 
AKBill said:
Edit: reread post. For an exhaust valve leak the only way I know is do a compression test, and as you said listen at the exhaust.
Click to expand...
Right. That's how we all do it, Bill.
I am thinking we can do better, but have not come up with the 'how'.
a) instant visual confirmation that the noise you hear is exhaust, not rings, not intake, not cylinder crack
b) quantification of the e-leak. There is always going to be leakage. What % is ring? What % is exhaust?
c) after you lap a valve in place, say there is still leakage. Quantification would tell you if you are making progress, and how fast.
 
the balloon thingy sounds good....maybe put em on each exhaust stack?....and watch em pump up? :D
 
I'd have to remove the exhaust from the cylinders on mine then fabricate risers to connect to balloons....as my exhaust is a 3 into 1 welded affair (IO-520)
 
Let'sgoflying! said:
I was thinking I could put a balloon over the exhaust stack as a visual indication of exhaust valve leaks - but I think what would happen is the leaking air would simply go into an adjacent exhaust valve & out an intake, or leak through an exhaust slip joint.
So we are left with someone holding the prop while someone else listens at an exhaust stack.

I'd like to come up with a way to verify the exhaust valve leak, and to quantify it.

I know, on poa somebody says why or no need or dont do that; cmon how about offering ideas instead, this time? :)
Click to expand...

I'm wondering why after nearly 150 years with internal combustion engines, you can't believe we don't have the best methods and equipment to test and trouble shoot our engines?
 
GlennAB1 said:
Remove the exhaust and spray soap solution on the valves.
Click to expand...
Yeah,, lets introduce a good electrolyte and get some corrosion started in these aluminum heads.
 
Tom-D said:
I'm wondering why after nearly 150 years with internal combustion engines, you can't believe we don't have the best methods and equipment to test and trouble shoot our engines?
Click to expand...

Oh my gosh, Tom you really skipped over my post #3!!

"You don't need that
**We don't do it that way**
That's the wrong way
Why would you bother with
What could possibly be learned from
What possible benefit is there from"

Please try to be a little open-minded here!
No way in the world do I think we have nearly the best tools or methods for these engines. No way.

Try to add something helpful or at least positive to these conversations, please!
 
Let'sgoflying! said:
Oh my gosh, Tom you really skipped over my post #3!!

"You don't need that
**We don't do it that way**
That's the wrong way
Why would you bother with
What could possibly be learned from
What possible benefit is there from"

Please try to be a little open-minded here!
No way in the world do I think we have nearly the best tools or methods for these engines. No way.

Try to add something helpful or at least positive to these conversations, please!
Click to expand...
With all the advanced tech we have now, why hasn't your better way been found already?
 
Let'sgoflying! said:
Oh my gosh, Tom you really skipped over my post #3!!

"You don't need that
**We don't do it that way**
That's the wrong way
Why would you bother with
What could possibly be learned from
What possible benefit is there from"

Please try to be a little open-minded here!
No way in the world do I think we have nearly the best tools or methods for these engines. No way.

Try to add something helpful or at least positive to these conversations, please!
Click to expand...
When you find a better way, patient it, you'll be rich.
You didn't answer my question on why you don't belive we already know how to do these things.
 
just let Tom....be.....Tom. o_O
Let'sgoflying! said:
Oh my gosh, Tom you really skipped over my post #3!!

"You don't need that
**We don't do it that way**
That's the wrong way
Why would you bother with
What could possibly be learned from
What possible benefit is there from"

Please try to be a little open-minded here!
No way in the world do I think we have nearly the best tools or methods for these engines. No way.

Try to add something helpful or at least positive to these conversations, please!
Click to expand...
 
AKBill said:
Edit: reread post. For an exhaust valve leak the only way I know is do a compression test, and as you said listen at the exhaust. Low compression in one cylinder would identify the cylinder. To identify the cylinder exactly you would pull the muffler and listen at the cylinder.
Click to expand...
We do compression tests one cylinder at a time at TDC so identifying the cylinder is already done. :)
 
My old exhaust had the beaded joints with clamps where risers met collectors. Atlee Dodge would true the joints and give me new clamps and they'd still leak. The VISUAL EVIDENCE was impossible to overlook. I pitched that exhaust and got a new Acorn specifically for the slip joints. Their gutted muffler was a bonus. The plane ran better, CHTs were cooler, and I have zero exhaust leakage under the cowl. Exhaust systems need to be maintained, too.

Ask a performance minded cylinder shop to show you why Continental exhaust valves leak. Maybe get the geometry trued while the valve and guide is being repaired. Address the problem, not just the symptom.
 
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Just a few of the engine tools and aids which we did not have 150 years ago, and many now think to be indispensable:

-the digital timing protractor I mentioned above
-infrared thermometers
-the multi-cylinder EGT/CHT gauges
-the borescope

My question is, why does anyone think we must repress all suggestion and imagination of yet newer and better tools?!

I do so want to get off this topic of "the old way is the only way" (one which I anticipated and attempted to deflect at the very start, but failed).

I want to talk to people who can think outside the boring current standard and help come up with
great new things!

Hey, my cell phone has a dB meter. Maybe I could put it at the exhaust stack and compare readings between cylinders. (I have one right now that I think is leaking)
 
Why put the balloon over the exhaust? If the leak is not past a valve, it is past the rings. Would putting a balloon over the oil breather tube work better? If the balloon inflates, it's rings. If it doesn't, it's a valve.
 
-Extra sensitive infrared temp gun.
-bucket of ice
-coiled compressed air hose
-valve on spark plug fitting

Submerge hose in bucket for an hour and keep most of it in there. Turn your valve to begin letting conditioned air in the cyl. Take temp readings at exhaust stack. Repeat.

My dumb idea for the day (may actually work).
 
SkyDog58 said:
Why put the balloon over the exhaust? If the leak is not past a valve, it is past the rings. Would putting a balloon over the oil breather tube work better? If the balloon inflates, it's rings. If it doesn't, it's a valve.
Click to expand...
you musta missed the part about being deaf......o_O
 
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