What to do when you can't find +005 rings

[alwaysoar]

I've got a good A-65 cylinder that needs +005 rings, but if they're out there, I can't find them. I have a couple of compression rings exact size unknown that fit within tolerances, but I'd like a set, or at least an oil ring. Anybody have any? Short of boring to +015, is there any solution, such as cutting down +015 rings? I have an oil ring that gaps .040 (service limit .033).

Thanks for your help.

Ed@BTV VT
TF 527

[crispy critter]

Re: What to do when you can't find +005 rings

Ed,
The difference is .007 and that is a big gap and will let a lot more oil burn threw than you might think.If all your cylinders are standard bore I would recommend trying to find a good used cylinder.If you go .015 with one then you must do it to another on the oppiste side if the engine to balance out the difference.I may have a servicable standard size cylinder or if I don't I know someone who does.contact me off list for more info if your interested.

[Goneflyin]

Re: What to do when you can't find +005 rings

I watched an AP use a little hand crank grinding wheel with a thin stone(1/8") butt the ends of the ring to the stone and trim it till it fit, the tool looked like it was made to do just what he used it for. I would have liked to have seen the ring in a cylinder and check the fit. The Champ he did it on is still running.

Bill

[Forrest Barber]

Re: What to do when you can't find +005 rings

Never heard of .005 over. .015 is standard over size.....
Watch out for shade tree operations, sure I could fit rings too if necessary when the War is on and I had a Mission.
I had old Harley with one .060 oversize piston & cylinder on the front. SHE ran smoother than when both were standard.

[Karl Rigdon]

Re: What to do when you can't find +005 rings

I have a few NOS part # 35551+.005 compression rings for sure. I will have to look through my treasures to see if I have any oil rings. I will look later in the evening. If you are still intrested let me know. Also I see 2 pc 531491+.005 which I think are for a C85.

[alwaysoar]

Re: What to do when you can't find +005 rings

Preferred airparts has +.005 compression rings, but no oil rings. Forrest, what I'm basing what I need on is the overhaul manual that has an asterisk next to rings and in the footnote says go .005 over to meet service limits if needed. So I've been trying to find a set that size. Karl if you have an oil ring that's .005 over I'd like to get it.

I had an oddball situation in which one cylinder in my newly overhauled engine had very low compression, so I pulled the cylinder and found one ring badly worn after only 21 hours. Big mystery to me how that happened. The other rings gapped over .125, and I don't see how that would happen either unless they were bad rings to begin with. The serviceable limit is .033. I had the bore measured professionally and it came out .001 over new limit and well within serviceable limits, so basically in good shape. The valves are good, the bore is good, no scoring--it was all in the rings. So,I've been advised to try .005 rings.

Does anyone have an idea how one ring, the top compression ring, would be badly worn on one side, and the others would have such a large gap? A local said something about ring flutter (?). What's that?

Ed

[Goneflyin]

Re: What to do when you can't find +005 rings

If the cylinder is in spec what's the end gap of a standard ring measure. I had my cylinders which are chrome redone and they had to get special rings for them. I know on motorcycles with chrome bores the rings were a soft iron ring. Ring flutter is usually the ring bouncing in and out in the ring land(groove), my experience from race bike's was it was caused by a wavy or badly worn bore or badly ported two stroke, and usually spinning better than 2200 rpm.

Bill

[Karl Rigdon]

Re: What to do when you can't find +005 rings

Ed, I have a oil ring #530145 5D that I suspect is a +.005. Check the parts list to see if that is the right number. I will try it in a cylinder tomorrow.
Check the ring side clearance in the ring grove. Also if all the honing material is not cleaned from the cylinder you will get rapid ring wear. Clean the cylinder with hot soapy water, rinse and dry. Then wipe with oil. Cleaning with solvent does not seem to remove grinding materials as well as hot soapy water.
Be sure the wrist pin is not loose and if possible check that the big and the small end of the rod are parallel and there is no twist in the rod. Also if the cylinder is not relatively straight it can cause funny ring wear.
The parts I have I purchsed years ago at a estate auction (s) of commercial fisherman(s) that and other misguided people tried to use these small cont engines on air/ice boats. The parts I suspect came from Lou Liebe when he was alive. My engine is running on parts from him. I suspect that some of the parts Fresno Airmotive have in their add came from Lou's estate. They were NOS I heard he got after WW2.

[alwaysoar]

Re: What to do when you can't find +005 rings

Karl, Those are good points. All parts seem to be ok, at least the rods were sent out and tagged as was the wrist pin, and there's no play there. The piston is new. Maybe the cylinder was not exactly straight, but it was torqued properly and there was no leaking. The honing material might be the problem. I don't want to put it together and have the same thing happen again. I don't have individual part numbers for the rings, just what's in the overhaul manual.

Ed

[Len Petterson]

Re: What to do when you can't find +005 rings

On my friendsTorph we found good compresion but high oil consumption. (O290G)
Top ring was worn to the point where if "fell" into the cylinder, it was castiron ring, 2nd ring was cromed it held the compresion. The oil rings also fell in.Also black iron, no crome.
We noted what one cromed ring hade a tip with the crome worn of,this tip had a different radius then the rest of the ring and the contact area onto the cylinder wall was missing about 3/8" from the tip of the ring.
Remove the rings and set them into the resptive cylinder and check the end clearnce, I take it you did what.Also check how it sits along the cylinder wall.
Warped cylinder will give a uneven wear as well as worn piston groves. Check the clearnce in the ring grove it may very well vary at different places so check it at 4- 5 spot around the piston.
Ckeck piston to cylinder clearance, maybe to large both of this may makes it necessary to change pistons.
The rings in the O290 is to be placed in the following order top ring is cromed then black then cromed oil rings.just to compare notes.
Try gilberts custom aircraft Brantford Ontario. www.execulink.ca/~gca
Len

[Forrest Barber]

Re: What to do when you can't find +005 rings

Go to .015 I am telling you that you cannot "hone" to the proper bore. The "chatter" is common with bogus parts. Sure I have done that in the past. I learned a lot since 1950..... I was 8 yrs old working with my Dad in his shop.... The .005 ring is a quick fix with the SAME pistion ( I think) Karl will straighten me out on that one. Lou Leibee and I think Velma?? what a story , right Karl... The bore needs to be trued up , the rings need fitted correctly, AND she needs the proper break-in oil too...

[Karl Rigdon]

Re: What to do when you can't find +005 rings

I agree with Forest the .005 OS ring is a quick short time fix. If that OS is required the cylinder needs to be brought back to service limits for truly long time life. Taper,out of round,and/or low spots will cause ring wear and sealing problems. Keep in mind I am not A&P rated however I worked on R1820 & R3350 turbo compound engines while in the Navy. I did work in an automotive machine shop for a few years after leaving the Navy. The service procedures are the same in both cases for long and trouble free service.
My departure from Forest is I like to chrome back to STD limits. Oil consumption can be a problem with chrome. After working with round engines and earlier auto engines I do not let oil consumption bother me unless plug fouling and smoke are a problem. The large radials can use 2 gallon per hour with a limit of 4 gallon per hour. Check the service manual for the A65. Max oil consumption is listed as 3/4 pint per hour. Do the math that is less than 3 hr per quart. Yes I know, fill it with oil and check the gas. Using chrome one may get a second bite at the apple with these old engine components.
I was told Lou Liebe scoured the South Seas islands and other military depots for these NOS parts after WW2. THINKING AHEAD!!!!! When Lou was still with us I had ordered a spare set of the stellite face "A80" exhaust valves which he aparently could not supply at that time. He replaced the order with 4 Continental part # 639662 100 OCT valves. That had to be a revenue loss. He did not leave me holding the bag. Those were the days!!!!

I did try the 530145 D5 oil ring in a STD cylinder and there was zero gap (.001 or .002) at the STD dia near the open end of the cylinder. That for sure is a +.005 OS ring. Using this ring you must check the end gap at the ring position when the piston is at bottom dead center.

[alwaysoar]

Re: What to do when you can't find +005 rings

Karl, Things seem to work out. I've come up with a standard cylinder in good shape, no out of round or low spots, must be very low time, so my dilemma is no longer a dilemma. You did some serious educating that's much appreciated.

Ed

[Forrest Barber]

Re: What to do when you can't find +005 rings

Gosh I like it when it works out! Karl & I still agree , yes I like to chrome back to Std also in a lot of situations. IF you want to do that do not bore out to .015 THAT can't be chromed back.( to my knowledge) Now Karl can answer one for me , I was TOLD that the Military specs were kept very loose and those engine specs allowed for a lot of oil consumption. they did not change oil , just kept adding oil.
The Military always wanted FOUR replacement parts for each and every one on each ship. WE had a lot of surplus stuff left over after WWII and ITS still out there. I have stuff from Lou to this day. The Jacobs engine folks and the Radial engine rebuilders in Tulsa?? tell me they have brought the oil consumption and leaks way down on all the big round engines with closer modern tolerances. I think the oils are better too!! I DID my A-65 with .015 over cylinders and drilled the rods ( ala A-75) then I run her at 2250 RPM and get almost 100 mph. Had Breakfast with Bruce & Jimmy at the Tri-City airport ( they came over in their BC12D) then instructed two sessions in my BC12D, what a great life!! Airport Fun-Day was great too. Did 6 dep fried turkeys and hauled 18 Young Eagles...

[Karl Rigdon]

Re: What to do when you can't find +005 rings

OIL CHANGE, What is that? I never knew the military to change oil except after engine failure and/or engine change. The only airplane I really did any refueling was the UF1 I was assigned to as plane captain (crew chief to the AF types) while stationed on Adak. This was 44 years ago however I seem to remember adding 1 to 2 gallon for each hour flown. As I remember the oil tank held at least 30 gal.
I do not know if the tolerances were much larger as if we had to replace a cylinder we just traded for a new/reman part. Yes we always seemed to have parts and equipment.
The tolerances may have been some looser for the power the military used on these engines. Using 115/145 fuel the R1820 on the UF were run up to 2700 & 51.5 inch MP takeoff power and I was told the R1820 on the T28 went to 56 IN MP. With the fuel today they cannot get near those power settings. After Adak I was at Moffet Field in Calif. working on the Super Connie. The R3350 turbo compound engines on that airplane were run to 2900 and 56 in MP. I was told that engine on the P2V went to 61 in MP and that may have been with water injection. The oil was probably non detergent and we generally used 1100 that I think is SAE50. At Moffet I was doing 200hr inspections on the engines (3 to 4 people) on each engine. Part of that inspection was to remove the propeller dome them remove the cam assy and clean the sludge from the inside of the dome. The centrifugal force would pack 1/2/in or more of sludge on the inside of the dome. That other than the screen was to only thing resembling a filter. Everyone got their turn at that job. That stuff was black and it was a dirty job.
I am sure you are right that with the better oil they may have tightened the tolerances. I have heard some of the T28 owners got the oil consumption and leakage down to nil.
On my A65 I have std chrome cylinders, drilled rods and A80 satellite face exhaust valves and also cruise at 2250 and show 95 with a 74/45 metal prop. I understand the 2150 RPM cruise was a function of the soft exhaust valves and the no lead 73 octane fuel. I am often asked at what airspeed I use for climb and I tell them 2300 RPM. I set the pitch so the engine turns 2300. I feel this gives the best rate and forward speed for engine cooling.
I to have some NOS parts from Lou Liebe.
Oh yes, while stationed on Adak I had the only occasion to see a ravel fabric tester. The UF1 had fabric control surfaces. We were well equipped.