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Lifters and stuck valves

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GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Mon Feb 20, 2006 10:32 am Post subject: Lifters and stuck valves

I'm surprised no one wrote in to comment on what I found.

_________________
Gary
AuCountry Aviation
Home of Team Grumman

jamey

Joined: 10 Jan 2006
Posts: 124

Posted: Mon Feb 20, 2006 10:57 am Post subject: Lifters and stuck valves

It was my plane so I already had the chat with you.  I also helped you clean

the lifters for #3 which were binding so you've got no arguments from me:)



Jamey



AA5B N72T (at) KSQL (okay, AUN for cylinders)

A36 N7218R (at) KSQL



--

gilalex(at)earthlink.net
Guest

Posted: Mon Feb 20, 2006 7:02 pm Post subject: Lifters and stuck valves

Gary... doesn't   SB388C also call out a cleaning of the lifters at the 

same time as the infamous "wobble check"??



If so, should be done every 400 hrs (old cylinders...)      ....gil in Tucson



[quote]--

ardri(at)comcast.net
Guest

Posted: Mon Feb 20, 2006 7:17 pm Post subject: Lifters and stuck valves

TeamGrumman(at)aol.com wrote:

 	  Quote: 	
		   



 I'm surprised no one wrote in to comment on what I found.



   

OK, I'll comment,
	




If the tappets are varnished and carbon-coated, doesn't that also imply

a temperature problem? Or are they generally like this when

disassembled? (Maybe I should leave out the "or", given the temperature

problems so common to our Lycomings.)



When the old cylinders on the Cheetah failed the wobble check at 400

hours SOH, the #4 cylinder also had out-of-tolerance DTC on the exhaust

valve due to a tuliped and eroded valve head. More over-temperature

damage, I suspect.



- Geoff Hickey -

Cheetah N26681

ardri(at)comcast.net
Guest

Posted: Mon Feb 20, 2006 7:17 pm Post subject: Lifters and stuck valves

TeamGrumman(at)aol.com wrote:

 	  Quote: 	
		   



 I'm surprised no one wrote in to comment on what I found.



   

OK, I'll comment,
	




If the tappets are varnished and carbon-coated, doesn't that also imply

a temperature problem? Or are they generally like this when

disassembled? (Maybe I should leave out the "or", given the temperature

problems so common to our Lycomings.)



When the old cylinders on the Cheetah failed the wobble check at 400

hours SOH, the #4 cylinder also had out-of-tolerance DTC on the exhaust

valve due to a tuliped and eroded valve head. More over-temperature

damage, I suspect.



- Geoff Hickey -

Cheetah N26681

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Mon Feb 20, 2006 8:17 pm Post subject: Lifters and stuck valves

It's possible that is was heat.   But, not very likely.   My guess is it 

wasn't flown enough.   It did sit for a number of years.   However, it has been 

flown regularly for the last 4 years.   



I'm wondering, Geoff, how many hours since Top?   If your valves had been 

heated to the point of melting, (going into the plastic range), there is a very 

good chance the valve clearance was zero (or less).



The valve piece I found in the muffler had been heated to the point that most 

of the valve seat mating surface had heat stress cracks in them.



I'm still going to be checking my valve tappet clearance every 100 hours or 

so.   Just in case.



Gary

PS, I can do that with my own plane.

_________________
Gary
AuCountry Aviation
Home of Team Grumman

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Mon Feb 20, 2006 8:35 pm Post subject: Lifters and stuck valves

In a message dated 2/20/06 7:04:33 PM, gilalex(at)earthlink.net writes:

 	  Quote: 	
		   Gary... doesn't=A0=A0 SB388C also call out a cleaning of the lifters at the

 same time as the infamous "wobble check"??



 If so, should be done every 400 hrs (old cylinders...)=A0 ....gil=20in

 Tucson




	


Well, yes, I guess it does.   Hadn't thought of it.

_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)ashcreekwirele
Guest

Posted: Tue Feb 21, 2006 6:00 am Post subject: Lifters and stuck valves

Unless SB388C is different from SB388B in this regard (I don't think it is), 

there is nothing that deals with cleaning or inspecting the hydraulic 

lifters.



Cliff

---

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Tue Feb 21, 2006 11:10 am Post subject: Lifters and stuck valves

In a message dated 2/21/06 6:01:12 AM, flyv35b(at)ashcreekwireless.com writes:

 	  Quote: 	
		   Unless SB388C is different from SB388B in this regard (I don't think it 

 is),

 there is nothing that deals with cleaning or inspecting the hydraulic

 lifters

 


	


Part One, Paragraph 4



"4. All Engines: Remove push rods, shroud tubes and hydraulic tappet 

assemblies. Disassemble tappet and clean as described in the applicable overhaul 

manual."



The caveat is, the overhaul manual is vague on how to clean. 



ALL of the lifters (tappets) in the engine I mentioned were stuck.   Even 

after bleeding the oil out of the tappets, I could NOT compress them; not even a 

few thousanths of an inch.   I have no doubt that the valves were not closing 

like they should.



I soaked them in carburetor cleaner over night and that still did not loosen 

them all up.   



I'm still going to be looking closer at the dry tappet clearance in the 

future.



Gary

_________________
Gary
AuCountry Aviation
Home of Team Grumman

flyv35b(at)ashcreekwirele
Guest

Posted: Tue Feb 21, 2006 3:26 pm Post subject: Lifters and stuck valves

You are so right Gary, I overlooked that paragraph!



Why where the lifter stuck?  Varnished up, rusted or what?



Cliff

---

jamey

Joined: 10 Jan 2006
Posts: 124

Posted: Tue Feb 21, 2006 4:41 pm Post subject: Lifters and stuck valves

Gary put me to work cleaning these up for #3 before we moved the plane to

Auburn so I believe I'm qualified (modulo my imperfect memory) to answer:)



They were varnished and once cleaned of this they seemed to work quite well

and there was no apparent corrosion or pitting on the two I worked with.



Jamey

AA5B N72T (the plane with the sticky lifters)

A36 N7218R



--

GrummanDude

Joined: 15 Jan 2006
Posts: 926
Location: Auburn, CA

Posted: Tue Feb 21, 2006 7:55 pm Post subject: Lifters and stuck valves

In a message dated 2/21/06 4:42:14 PM, jamey(at)jamescourtney.net writes:



 	  Quote: 	
		   You are so right Gary, I overlooked that paragraph!



 Why where the lifter stuck?=A0 Varnished up, rusted or what?



 Cliff



They appeared to have varnish and carbon, similar to what you'd see on inside
	


of a rocker cover on an old car that had hundreds of thousands of miles on it

without changing the oil.   Not sludgy.   But, cake and baked on carbon and

varnish.  



When I bought my plane, it had 1100 hours on it.   80 hours in the last 10

years.   THe inside of the block had caked on sludge.   It took hours to scrape

it off.   I poured about 10 gallons of fuel through the engine to was as much

through as i could.   The oil filter on the first few oil changes was pretty

full of junk.   So was the oil screen.  



The lifters and tappets didn't look that bad though.  



Gary

_________________
Gary
AuCountry Aviation
Home of Team Grumman

gilalex(at)earthlink.net
Guest

Posted: Tue Feb 21, 2006 8:06 pm Post subject: Lifters and stuck valves

 	  Quote: 	
		  

Part One, Paragraph 4



"4. All Engines: Remove push rods, shroud tubes and hydraulic tappet

assemblies. Disassemble tappet and clean as described in the applicable 

overhaul

manual."



The caveat is, the overhaul manual is vague on how to clean.


	




My manual just says "use clean solvent" ... pretty generic...:

)    gil A



 	  Quote: 	
		  Gary

FLYaDIVE(at)AOL.COM
Guest

Posted: Tue Feb 21, 2006 8:13 pm Post subject: Lifters and stuck valves

In a message dated 2/21/06 10:55:57 PM Eastern Standard Time, 

TeamGrumman(at)aol.com writes:



 	  Quote: 	
		   I poured about 10 gallons of fuel through the engine to was as much

  through as i could.   The oil filter on the first few oil changes was 

pretty
	


 	  Quote: 	
		    full of junk.   So was the oil screen.  

  

  The lifters and tappets didn't look that bad though.  

  

  Gary

=========================
	


Gary:



Fuel is a very POOR cleaning agent.  And too expensive as well as flammable.  

Try Mineral Spirits, it works VERY well.  You can prove it to yourself by 

cleaning an oil screen in gas and another in Mineral Spirits.  The spirits will 

have the oil totally disperse.  Also, when you let the spirits sit for a while 

the oil will separate from the spirits and you will have clean spirits to work 

with again.



I know the engine was not run much, but this makes a good argument for MMO 1 

hour before an oil change.  MMO also cleans the tappets.



Barry

"Chop'd Liver"

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