Wanted: A65 Cylinder 0.015 over

[Robert Lees]

Hi all,

For my stranded Tcraft in Oregon I need a replacement cylinder for its A65, and piston both ideally yellow tagged.

15 thou over is what it needs, but obviously it would be a waste to grind one down that is size or 0.005" ground.

All leads appreciated.

Rob

[Edit for clarification: All the cylinders are 0.015. I need a "new" 0.015 cylinder to match the other three, because the damaged cylinder cannot be repaired]

[mike lutz]

Re: Wanted: A65 Cylinder 0.015 over

Rob, you might specify which piston you need (large pin-small pin, how many rings, etc) so it will match what the others currently are. Makes for a smoother running engine.

[crispy critter]

Re: Wanted: A65 Cylinder 0.015 over

Rob,
Depending on which piston and pin you have..... I have 2 but not yellow tagged. They were removed in great running condition with compressions in the high 70's.

[Robert Lees]

Re: Wanted: A65 Cylinder 0.015 over

Thanks for replies to date...I will find out which piston is required. The cylinder is the main item.

My IA says:

"Yellow tagged is better because you know what your buying and it has
been inspected and has met overhauled specs. (new valve guide and
valve seat, new valves) Checked for cracks and repainted, etc.

If you get a servicable cylinder and piston, I can measure to see
that it meets at least servicable dimensions and install. But if any
measurement is less than servicable it will be rejected. Thats why it
is so hard to purchase one on ebay or from someones hangar storage.
You dont know what you are going to get."

I think I agree with him. By the time I've spent the money for the item and for shipping, I'd rather it be a "bolt-on" item rather than have to pay for the inspection & take the risk that it's not fit.

Rob

[Robert Lees]

Re: Wanted: A65 Cylinder 0.015 over

It appears to be a 4-ring piston, with pin diameter of 0.85"

[Guest]

Re: Wanted: A65 Cylinder 0.015 over

Rob,

Last year I sold my sets of yellow tag cylinder stud assemblies, cylinders with valves and cylinders with piston and rings.

I am telling you this so you get a feel for what they sell for.

Stud assemblies - chrome std or P15 bores with guides and seat either replaced or brought to spec sold for about $500 on average.

Valved assemblies which were as above plus had new or overhauled valves installed sold for about $575

Assembly that had all above plus a used serviceable piston, pin and new rings and gasket set sold for $565 (I must have really liked this person )

All of the above had fresh yellow tags and I sold 8 cylinders as I recall so that's some data about price.

If I were in your shoes I would send in the core to Harrison or Brown and have it fixed and tagged. I bet you will never find what you are looking for in the already tagged condition.

Dave

[Robert Lees]

Re: Wanted: A65 Cylinder 0.015 over

Thanks for those values, Dave, they'll give me a ballpark.

Re: your last paragraph, my A&P IA says the cylinder is scored by the piston pin, and being 0.015" over already is therefore scrap.

(I'm in his hands...I'm 7000 miles away in a different country). No point sending it to anyone.

Rob

[crispy critter]

Re: Wanted: A65 Cylinder 0.015 over

Someone please correct me if I'm wrong but isnt the "big (no AD) piston pin" suppose to meausre 0.90? Not sure what the +/- allowances are for the piston pin but until that's the bad one I think it's worn 0.05.....again, I'm trying to go by memory so please correct me if I'm wrong. The A65 overhaul manual will tell you this under the table of limitations but I don't have mine hue at them moment, it's at the airport.

[Guest]

Re: Wanted: A65 Cylinder 0.015 over

I think that the text below is the AD. Only pin i.d. is mentioned.

It's hard for me to imagine how a piston pin with aluminum caps installed can score a cylinder wall. So I wonder what was wrong with this initial installation? Must have had something amiss.

Rob, ask Harrison or Brown to sell you what you want then. I expect that they have P15 cylinders in stock and you can get the remaining parts from them or Fresno Airparts.

Dave


46-36-01 CONTINENTAL: (Was Mandatory Note 8 of AD-675-2: 11 of AD-728-1; 2 of AD-751-1; 1 of AD-761-2; 6 of AD-718-6; 9 of AD-737-1; 1 of AD-759-3; 11 of AD-729-1; 8 of AD-720-1; 2 of AD-611-1; 9 of AD-725-1; 11 of AD-691-1; 9 of AD-703-1; 5 of AD-740-1; 9 of AD-725-1; 10 of AD-694-4; 6 of AD-709-1; 8 of AD-730-2; 8 of AD-746-1; and 11 of AD-696-3.) Applies to Aeronca 65-CA; 65-TC, 65-TAC, YO-58; O-58A, O-58B, SO-58B; 11AC; Air Products (Erco) 415-C, 415-CD; CallAir S-1A; Champion 7AC, S7AC; Commonwealth (Rearwin) 175, 180, 185; Northwestern (Porterfield) CP-65, CS-65; 75C; Piper AE-1, HE-1; J3C-65, J3C-65S; J4, J4A, J4A-S; J4E; J5A, J5A-80, J5C; Silvaire (Luscombe) 8, 8A, 8B, 8C, 8D, 8E; Stinson HW-75, 10; Superior (Culver) LCA; Taylorcraft DC-65, DCO-65; Universal (Taylorcraft) BC, BCS, BC-65, BCS-65, BC12-65, BCS12-65, BC12-D, BC12-D1, BCS12-D1 Airplanes Having Continental A-65 Series Engines With Serial Numbers From 3456658 to 4109568, Inclusive; or Continental A-65, A-75, or A-80 Series Engines Which Have Had A-21422 Piston Pins or New 3-Ring Pistons Installed Since September 25, 1945.
Compliance required immediately if possible, but in any event not later than 50 hours of engine operation after August 27, 1946.
A certain percentage of piston pins installed in engines of the above numbers and distributed as replacement parts are subject to failure without warning. The weakness of these pins cannot be detected by normal inspection methods. Piston pin breakage can result in complete engine failure. It is the owner's responsibility to avoid this risk by making the changes outlined in (a) and (b) at the earliest possible time.
(a) Replace piston pin P/N A-21422 (0.626 inch inside diameter) with thick wall piston pin No. A-25127 (0.5945 inch inside diameter). The engine manufacturer has given assurance that every possible effort will be made to supply the required quantity of replacement piston pins.
(b) Simultaneously with (a), all pistons should be examined for skirt cracks and the necessity for rework of the bottom rib. This rework involves reducing the height of the rib until it is at least 1/16-inch wide and rounding all sharp corners.
(c) As an acceptable alternate to (a) and (b), cam ground pistons, P/N 40731, which necessitate using piston pins of greater outside diameter, may be installed. This change will likewise remove the possibility of piston pin failure and piston skirt cracking.
(Continental Motors Service Bulletin M46-6 covers this same subject.)

[waltermrich]

Re: Wanted: A65 Cylinder 0.015 over

Rob, this isn't related to the current topic but since its your post I thought I would chime in. When I last saw you at Blakesburg at our lunch you asked me where my Uncle was stationed in WWII in England, at that time I could not remember, but I now remember Him saying it was near the town of Ipswitch on the east coast of England , he was a turret gunner mechanic, and I can remember as a kid during holidays he would always be talking about his time there spending three years in a tent and working on his B17 Rumdum, that B17 went on with some notoriety as it came back with heavy battle damage, I have brought it up on the web and read about it , it went on to complete all its missions. Currently I have a friend named Cliff who sits next to me in our church choir in his mid 90's He trained to be a pilot but wound up being a navigator on a B17 based he said at Ridgeway near Cambridge, early on I think in 43 there b17 was shot down over France, he parachuted safely, but was captured by the Germans and spent the rest of the war at Stalag Luft 3, he said it was where the story of the movie the Great Escape was derived. He is a really nice old fellow and Im trying to get him to record his story, finish his log book I have told him. Thanks for all your stories they were great and I hope you get your Taylorcraft in the States flying

[Mark Bowden]

Re: Wanted: A65 Cylinder 0.015 over

I have a collection of scanned manuals from 1939 thru 2011 and will try and get them uploaded to the ref section. The only one that has a nominal pin diameter is from 1939. All subsequent manuals do not have nominal sizes which is strange.

Pin Dia. = 55/64. (0.8594)

Pin to piston limits from 1939 Continental Manual
Desired 0.0004
Min 0.0001
Max 0.0007
Max 0.0015 (Max allowable after use)

Pin to piston limits from Aug., 2011 Continental Manual
Min 0.0001
Max 0.0007
Max 0.0015 (Serviceable Limit)

Mark

[Guest]

Re: Wanted: A65 Cylinder 0.015 over

Someone please correct me if I'm wrong but isnt the "big (no AD) piston pin" suppose to meausre 0.90? Not sure what the +/- allowances are for the piston pin but until that's the bad one I think it's worn 0.05.....again, I'm trying to go by memory so please correct me if I'm wrong. The A65 overhaul manual will tell you this under the table of limitations but I don't have mine hue at them moment, it's at the airport.

Hi Kevin,

The caliper and the measurement appear to be for the purpose of showing the approximate pin size so as to identify the pin.

For example the caliber is a plastic 2 digit model. One would use a micrometer for a pin measurement.

Also we would hold the caliper jaws perpendicular to the pin if we wanted an accurate measurement.

Rob's mechanic is doing a good job of showing us that this is the small .859 pin not the big .922 and that it has a 4 ring piston.

I would not make any conclusion about condition based on this.

BTW- I posted the AD above.

Dave

[Edwin Otha]

Re: Wanted: A65 Cylinder 0.015 over

The .859 pin has a thin wall and a thick wall. Use the thick wall. Also the pin plugs are different use the correct one with the pin you choose. The cam ground pistons use the .912 pins with the pressed in plug. You will need a piston with a small pin or you'll have to re-bush the rod. The 4 ring pistons are a pretty early piston for the A50's&65's, if you can save it, I would.
EO

[Mark Bowden]

Re: Wanted: A65 Cylinder 0.015 over

Question, from the photo of the piston, if the A50, 65 is four rings and the A75, 80 is five rings is that an A75 piston in this rebuild? Wouldn't that require special paperwork on the rebuild to use the A75 pistons? At least a 337?

Do you have the drilled connecting rods too then?

Mark

[Robert Lees]

Re: Wanted: A65 Cylinder 0.015 over

The Tcraft engine is (on paper) an A-75. It certainly didn't wind up to A75 rpm like the Aeronca did, Mark.

But that was most likely due to the prop.

Rob