ColoRv
Well Known Member
Brown and Don George are cylinder overhaul companies and having experience with both now, I thought I should write up what I have learned (the hard way).
4 years ago I bought an angle valve engine in boxes, all of it had been overhauled or replaced with new. The previous owner had decided to save weight and went parallel valve. The crank, cam, hardparts were new, case and cylinders overhauled. I put a superior cold sump and Pmags on it during assembly (A&P and I assembled). The cylinders were overhauled by Brown Aviation in Tulsa and yellow tagged.
Some of you might remember I was having an issue in the first 50 hours with a cylinder going cold during cold starts. I had a valve sticking that was found (suggested here) by shutting down when the cylinder dropped out and rotating the prop through by hand. Sure enough, no compression on #3. I called Larry Brown and received a 30 minute discussion on how it was not a sticking valve. I explained how you could hear the valve snap shut and the compression came back but he refused to believe it.
When my A&P and I disassembled the valves springs etc to the check that valve, it was so stuck in the guide it wouldn't move by hand. Had to use a dead blow and wood dowel to move it. Lycoming's opinion on stuck valves is if it happens after 300 hours you're flying it wrong, if it happens prior to 300 hours....there was something wrong with the assembly. Inside of 50 hours and the overhaul shop blows you off ... that's not good. Anyway, rope trick and reamer later and the stuck valve was fixed. Reamer came off with metal, not carbon. Something was wrong with that guide install. The engine when fresh burned 1 quart in 10 hours. I assumed it was the Lycon 10:1 with all of the oil scavenge holes. I can live with 1 in 10 no problem.
Fast forward 3 years and 500 hours and oil burn increased to 1 quart in 2 hours. Compression was 75/76/77/77, borescope showed wet piston tops but cylinder walls looked fine (nothing obvious). Intake tubes had oil in them, as did the servo. I called Larry Brown and walked him through what I had checked and said I thought the cylinders needed a look. I wasn't expecting a warranty, just wanted the cylinders gone through to tell me where the oil was going and what it would cost to fix it. Having had trouble with one guide already I suspected the guides, my A&P suspected an oil ring or glazing. What I got from Larry was a 30 minute lecture on how my RSA5 was clearly poorly overhauled by Airflow Performance and I should send it in for a fresh overhaul by someone who knows what they are doing. My servo is washing my cylinder walls with fuel and burning the oil out.
I wasn't buying it and my A&P laughed. Then how am I getting so much oil in the intake? I did some searching and found Don George in Orlando. That is nearly local so I called him and ran him through what I had experienced. He said clearly something was off with an oil burn that high but until he saw them he couldn't say what. He shrugged off the servo suggestion. I pulled the cylinders and took them over. Pulling the pistons he said there was certainly blowby but nothing alarming. With it so close to overhaul he didn't expect to find anything in the valvetrain but would disassemble and check anyway.
Two days later Don called and told me what they found. None of the valves are within spec. They are all significantly worn. Of the 8 valve guides, only one passed the go/no go gauge and that was the one we Reamed three years ago. Two of the cylinders had cracks by the spark plugs. He showed me the cylinders when I returned and handed me the go/no go gauge. It didn't just go in, it went in and wobbled around, top and bottom. I mean wobbled big time. Those guides were worn completely out.
Of course I'm thinking, Jesus what have I done wrong while flying this engine? Don said, let me show you something. He flips the cylinders back over and points to the guide we had reamed (the only one that passed). See the flange on the top of the guide? See how the rest of them don't have one? Replacement valve guides typically have a flange on them. Stock lycomings typically do not. None of the failing guides looked like they had been replaced in the overhaul and clearly none of the valves had. These cylinders were simply worn completely out. The one that had been replaced that we had to ream at 50 hours....passed the gauge tests top and bottom. It clearly isn't about how I was flying it or that one would have been shot as well.
Nothing broke, they were just so loose they were squirting oil into the combustion chamber. Don was great about educating me on cylinders while I was there. The exhaust ports on two of my cylinders were cut into the fins. They didn't stand out like the others showing they had been reworked. There were numerous weld repairs that he pointed out and showed me the cracks around the spark plugs. Some of the valve seats had been replaced already as well though that wasn't on the receipt from Brown. Odd. There is no crystal ball of course....he was just making observations on what he saw. Decisions were up to me.
Don said, we don't make money telling you to buy new cylinders. We make money overhauling these but you'll be back here with some other issue before TBO. These are just worn out. Too many welds, too many cracks, oversized valve seats.....these are airboat cylinders.
So home I went, to look up new cylinder prices to see if I could beat his price of $8800 (I couldn't). He said he had a set of first run turbo cylinders which had run to tbo without issues. He could overhaul those for half the price of new and thats the direction I went. New valves, guides, springs, keepers etc...my Lycon pistons (which looked great still) cleaned up and installed in a fresh bore. His overhaul came with every gasket, o ring and hardware as well. He even had the oil returns and manifold pressure taps installed as I had.
As I went through my build there were a couple vendors that stood out. Stein Air of course, Airflow Performance, Plane Schemer and Evoke Painters for certain but I think I can add one more. Don George has been impressive thus far.
An overhaul is judged by longevity of course and I can't speak to that on the Don George overhaul as yet....but I can speak to Larry Brown's. Every phone call was an excercise in frustration and his work didn't get to 500 hours in a plane that flies regularly. Everyone has an off day, but his constant refusal to even look at the cylinders even when they are burning .5 quart an hour and bathing the intake tubes in oil tells me this wasn't just a bad day. I didn't send those cylinders to him for overhaul and maybe he was doing what the previous owner asked for but a yellow tag should mean something more than what he did in my mind, I can't recommend Brown Aviation from my experience with them. Don George, on the other hand never made my BS meter move. He showed me every single thing he found so I could see with my own eyes. We shall see in a few years of flying of course but I don't believe that shop cuts corners at all.
4 years ago I bought an angle valve engine in boxes, all of it had been overhauled or replaced with new. The previous owner had decided to save weight and went parallel valve. The crank, cam, hardparts were new, case and cylinders overhauled. I put a superior cold sump and Pmags on it during assembly (A&P and I assembled). The cylinders were overhauled by Brown Aviation in Tulsa and yellow tagged.
Some of you might remember I was having an issue in the first 50 hours with a cylinder going cold during cold starts. I had a valve sticking that was found (suggested here) by shutting down when the cylinder dropped out and rotating the prop through by hand. Sure enough, no compression on #3. I called Larry Brown and received a 30 minute discussion on how it was not a sticking valve. I explained how you could hear the valve snap shut and the compression came back but he refused to believe it.
When my A&P and I disassembled the valves springs etc to the check that valve, it was so stuck in the guide it wouldn't move by hand. Had to use a dead blow and wood dowel to move it. Lycoming's opinion on stuck valves is if it happens after 300 hours you're flying it wrong, if it happens prior to 300 hours....there was something wrong with the assembly. Inside of 50 hours and the overhaul shop blows you off ... that's not good. Anyway, rope trick and reamer later and the stuck valve was fixed. Reamer came off with metal, not carbon. Something was wrong with that guide install. The engine when fresh burned 1 quart in 10 hours. I assumed it was the Lycon 10:1 with all of the oil scavenge holes. I can live with 1 in 10 no problem.
Fast forward 3 years and 500 hours and oil burn increased to 1 quart in 2 hours. Compression was 75/76/77/77, borescope showed wet piston tops but cylinder walls looked fine (nothing obvious). Intake tubes had oil in them, as did the servo. I called Larry Brown and walked him through what I had checked and said I thought the cylinders needed a look. I wasn't expecting a warranty, just wanted the cylinders gone through to tell me where the oil was going and what it would cost to fix it. Having had trouble with one guide already I suspected the guides, my A&P suspected an oil ring or glazing. What I got from Larry was a 30 minute lecture on how my RSA5 was clearly poorly overhauled by Airflow Performance and I should send it in for a fresh overhaul by someone who knows what they are doing. My servo is washing my cylinder walls with fuel and burning the oil out.
I wasn't buying it and my A&P laughed. Then how am I getting so much oil in the intake? I did some searching and found Don George in Orlando. That is nearly local so I called him and ran him through what I had experienced. He said clearly something was off with an oil burn that high but until he saw them he couldn't say what. He shrugged off the servo suggestion. I pulled the cylinders and took them over. Pulling the pistons he said there was certainly blowby but nothing alarming. With it so close to overhaul he didn't expect to find anything in the valvetrain but would disassemble and check anyway.
Two days later Don called and told me what they found. None of the valves are within spec. They are all significantly worn. Of the 8 valve guides, only one passed the go/no go gauge and that was the one we Reamed three years ago. Two of the cylinders had cracks by the spark plugs. He showed me the cylinders when I returned and handed me the go/no go gauge. It didn't just go in, it went in and wobbled around, top and bottom. I mean wobbled big time. Those guides were worn completely out.
Of course I'm thinking, Jesus what have I done wrong while flying this engine? Don said, let me show you something. He flips the cylinders back over and points to the guide we had reamed (the only one that passed). See the flange on the top of the guide? See how the rest of them don't have one? Replacement valve guides typically have a flange on them. Stock lycomings typically do not. None of the failing guides looked like they had been replaced in the overhaul and clearly none of the valves had. These cylinders were simply worn completely out. The one that had been replaced that we had to ream at 50 hours....passed the gauge tests top and bottom. It clearly isn't about how I was flying it or that one would have been shot as well.
Nothing broke, they were just so loose they were squirting oil into the combustion chamber. Don was great about educating me on cylinders while I was there. The exhaust ports on two of my cylinders were cut into the fins. They didn't stand out like the others showing they had been reworked. There were numerous weld repairs that he pointed out and showed me the cracks around the spark plugs. Some of the valve seats had been replaced already as well though that wasn't on the receipt from Brown. Odd. There is no crystal ball of course....he was just making observations on what he saw. Decisions were up to me.
Don said, we don't make money telling you to buy new cylinders. We make money overhauling these but you'll be back here with some other issue before TBO. These are just worn out. Too many welds, too many cracks, oversized valve seats.....these are airboat cylinders.
So home I went, to look up new cylinder prices to see if I could beat his price of $8800 (I couldn't). He said he had a set of first run turbo cylinders which had run to tbo without issues. He could overhaul those for half the price of new and thats the direction I went. New valves, guides, springs, keepers etc...my Lycon pistons (which looked great still) cleaned up and installed in a fresh bore. His overhaul came with every gasket, o ring and hardware as well. He even had the oil returns and manifold pressure taps installed as I had.
As I went through my build there were a couple vendors that stood out. Stein Air of course, Airflow Performance, Plane Schemer and Evoke Painters for certain but I think I can add one more. Don George has been impressive thus far.
An overhaul is judged by longevity of course and I can't speak to that on the Don George overhaul as yet....but I can speak to Larry Brown's. Every phone call was an excercise in frustration and his work didn't get to 500 hours in a plane that flies regularly. Everyone has an off day, but his constant refusal to even look at the cylinders even when they are burning .5 quart an hour and bathing the intake tubes in oil tells me this wasn't just a bad day. I didn't send those cylinders to him for overhaul and maybe he was doing what the previous owner asked for but a yellow tag should mean something more than what he did in my mind, I can't recommend Brown Aviation from my experience with them. Don George, on the other hand never made my BS meter move. He showed me every single thing he found so I could see with my own eyes. We shall see in a few years of flying of course but I don't believe that shop cuts corners at all.
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