A-65-8 Overhaul - Advice Wanted

Arnold

Arnold

Cleared for Takeoff
Joined
Mar 8, 2005
Messages
1,483
Location
Philadelphia Area
Display Name
Display name:
Arnold
Lady Luscombe's engine needs a bottom overhaul. With 27 hours on new millenium cylinders the oil tank sprung a leak and dumped the oil. Pressure did not drop until I reduced power for landing when the sound of a broken piston rod banging around assaulted my ears. The oil tank has been welded. The engine is at a shop where they have not touched in since they got it a month ago. I understand they are busy so I'm thinking about pulling it and at least tearing it down myself. Sending parts needing inspection to a reputable shop and then reassembling. The cylinders seem to undamaged - yay.

Questions:

Any special tools needed for disassembly?
Any special tools needed for reassembly assuming I have normal auto engine overhaul tools available?
Any reason I can't do this with knowledgeable assistance and an A&P with a pen at the ready?

Thanks in advance.
 
Those engines are dirt simple. Tear down and reassembly is pretty easy as long as you have an overhaul manual for the engine. Anyone who has any sort of mechanical aptitude should be able to accomplish this.

About the only special tool I can think of that you would need is a wrench to remove and replace the cylinder base nuts. You cannot get to them with a regular torque wrench. They can be purchased relatively cheaply.
 
Arnold said:
Thanks Greg that was my impression.
Click to expand...
you'll need a 1/2" and a 9/16th cylinder wrench, (Aircraft spruce) and plastigauge (NAPA) one stick red, and one stick green, and 3 feet of #50 silk thread.
 
And just what in the world is the silk thread for, some of you may ask? That is actually the gasket that goes between the case halves on these engines.
 
Greg Bockelman said:
And just what in the world is the silk thread for, some of you may ask? That is actually the gasket that goes between the case halves on these engines.
Click to expand...

I thought maybe it was a MacGyver thing. List to include: two paperclips, some used chewing gum, and a 1998 Ken Griffey, Jr. Topps baseball card.
 
If you’re an A&P you can rebuild it legally. Aircraft owner? Not so much. However, if an A&P is willing to sign off your work you’re good to to go.
 
Brad Smith said:
If you’re an A&P you can rebuild it legally. Aircraft owner? Not so much. However, if an A&P is willing to sign off your work you’re good to to go.
Click to expand...
Which was mentioned by Arnold in the original post.
 
A broken (or even loose) con rod indicates major internal damage. Crank is likely shot, and they're scarce. Maybe the cylinders survived.
Ask me how I know.
 
Greg Bockelman said:
And just what in the world is the silk thread for, some of you may ask? That is actually the gasket that goes between the case halves on these engines.
Click to expand...
A little sticky helps.
 

Attachments

  • IMG_0948.jpeg
    IMG_0948.jpeg
    83.4 KB · Views: 33
Dan Thomas said:
A broken (or even loose) con rod indicates major internal damage. Crank is likely shot, and they're scarce. Maybe the cylinders survived.
Ask me how I know.
Click to expand...
I suspect you may be right. Won’t know for sure until the case gets split.
 
Arnold said:
Any reason I can't do this with knowledgeable assistance and an A&P with a pen at the ready?
Click to expand...
No reason. But may want to get a copy of an OH manual and go over the steps first and perhaps work out a vendor for your replacement parts as well. Also might want to check on who still offers machining work in case you need some. Have heard of several shops dropping the A/C models from their work scopes.
 
Bell206 said:
No reason.
Click to expand...
How many A&Ps do you know that has the tools and materials to rework a case ?

(b) Each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition (with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness).
 
Last edited:
kyleb said:
How'd you conclude reworking a case was necessary?
Click to expand...
Reworking the case is necessary anytime the case is removed, they warp in usage, and the way to get them to proper clearances is to Lapp, and line bore them. = rework them
 
Tom-D said:
How many A&Ps do you know that has the tools and materials to rework a case ?
Click to expand...

From this post I don't see where he advocated an A&P to rework the case:

Bell206 said:
No reason. But may want to get a copy of an OH manual and go over the steps first and perhaps work out a vendor for your replacement parts as well. Also might want to check on who still offers machining work in case you need some. Have heard of several shops dropping the A/C models from their work scopes.
Click to expand...

That indicates to me that "who still offers machining work in case you need some" to be a shop that does that sort of work.
 
Tom-D said:
Reworking the case is necessary anytime the case is removed, they warp in usage, and the way to get them to proper clearances is to Lapp, and line bore them. = rework them
Click to expand...

No. It is not required "anytime" a case is removed. Sometimes, yes. Many times, maybe. Anytime, no.
 
kyleb said:
No. It is not required "anytime" a case is removed. Sometimes, yes. Many times, maybe. Anytime, no.
Click to expand...
If it ain't a fresh overhaul it ain't good enough for me.
 
Tom-D said:
How many A&Ps do you know that has the tools and materials to rework a case ?

(b) Each person maintaining or altering, or performing preventive maintenance, shall do that work in such a manner and use materials of such a quality, that the condition of the aircraft, airframe, aircraft engine, propeller, or appliance worked on will be at least equal to its original or properly altered condition (with regard to aerodynamic function, structural strength, resistance to vibration and deterioration, and other qualities affecting airworthiness).
Click to expand...
Plenty.
 
RyanShort1 said:
Boy, the internet is grouchy today. I said I knew plenty of A&P's with that stuff, and I do... not that I have it myself.
Click to expand...
OBTW,, those tool are very expensive, they are mostly owned by CRS machine shops.
The last one I saw was at NAS Whidbey where I worked for 12 years. one day it disappeared. No I didn't get it.
 
Tom-D said:
How many A&Ps do you know that has the tools and materials to rework a case ?
Click to expand...
???. Never said they needed them. Only stated check with shops first as some don't have the equipment either or quit working on the old A and C model engines.:rolleyes:
 
Bell206 said:
No reason. But may want to get a copy of an OH manual and go over the steps first and perhaps work out a vendor for your replacement parts as well. Also might want to check on who still offers machining work in case you need some. Have heard of several shops dropping the A/C models from their work scopes.
Click to expand...

Among them Penn Yan.
 
Shops pretty much end up dropping such old engines because they can't get parts for them. Too many are running around with worn-out stuff in them. The A-65 was last built in 1966, 55 years ago. Old stuff. Superior has cylinders but I don't know of anyone making crankshafts. The A-65 I had in my Jodel was built in 1946. The designers and builders never had any idea that we would want them to last so long.

If the OP's engine really did throw a rod, there is likely serious case damage. Could be a cracked crank, too, though if it ran low on oil the journals will all be shot. The cranks in these engines were never nitrided, so the bearing surfaces are soft and easily scored and worn. The oil pumps wear, too, and the pump bore is part of the accessory case casting and non-replaceable. Low oil pressure means bearing wear, and they also tend to leak oil out when they sit so that the engine gets no oil for some time, if ever. Many owners have to prime that pump before they start up. The front crank journal is the last to get the oil after startup, so it wears the most.
 
Dan Thomas said:
Shops pretty much end up dropping such old engines because they can't get parts for them. Too many are running around with worn-out stuff in them. The A-65 was last built in 1966, 55 years ago. Old stuff. Superior has cylinders but I don't know of anyone making crankshafts. The A-65 I had in my Jodel was built in 1946. The designers and builders never had any idea that we would want them to last so long.

If the OP's engine really did throw a rod, there is likely serious case damage. Could be a cracked crank, too, though if it ran low on oil the journals will all be shot. The cranks in these engines were never nitrided, so the bearing surfaces are soft and easily scored and worn. The oil pumps wear, too, and the pump bore is part of the accessory case casting and non-replaceable. Low oil pressure means bearing wear, and they also tend to leak oil out when they sit so that the engine gets no oil for some time, if ever. Many owners have to prime that pump before they start up. The front crank journal is the last to get the oil after startup, so it wears the most.
Click to expand...

For sure? but that is why we are seeing the 65/85 updated to the 0-200 cranks, rods, and cylinders. the repairs of the case, and accessory case are having hard time finding parts.
Trouble is, no one thought the accessory cases,and oil pump gears would wear out.
 
You must log in or register to reply here.
Back
Top