Helmetfire
Registered User
Caldwell, Texas
I bought my '54 Super Cub back in Oct of last year. Purchase was contingent on a fresh annual that returned some minor airframe discrepancies that were addressed accordingly. After the annual the owner asked if I wanted him to test fly the plane after inspection, he still owned the plane so I agreed of course. During that flight the engine started to run rough. Got it back down, started tearing into the engine only to find out on cylinder was bad. Then they looked closer at the bottom end and realized that the engine needed to be overhauled. The seller and i re-negotiated the price of the plane to reflect the cost of an overhaul. The mechanic claimed he's been rebuilding engines for 50 years, so I decided to trust him and give the guy my business...the airplane was already torn apart in his hangar, so it saved me a bunch of hassle hauling engine parts all over the countryside...(his place is a 2 hour drive from where I live).
The day fianally came where the plane was ready to run. The first break-in flight lasted about 30 mins and for the most part went well. The plane seemed to have excess vibrations but I was a greenhorn cub pilot, so I really wasn't sure what "normal" felt like yet. Plus, the prop had been dynamically balanced prior to the overhaul, and the mech said he didn't mark the prop orientation prior to removal and took all original balance weights off anyway. Tried to fly it home that day but spent an hour flying in some shitty rainy weather trying to make it over the mountains, and couldn't make it home. Eventually got the plane home a few days later.
I was never happy with the engine. It seemed to run well and made good power, but vibrated more than i thought should. Also burned very little oil, and the oil was staying pretty clean. For a while I thought it was the Sensenich prop causing the vibration, seems I always read on here how bad the Sensenich prop was for vibration. Had the prop dynamically balanced, no change. Had the prop checked out by a prop shop, no change. Tried a different prop same model, no change. Each time I'm trying to convince myself that things are improving, but really they weren't. Bought a brand new Borer prop that everyone swears is smoother than the Sensenich. This time I could tell that the prop was running smoother, but since it was so smooth, it really highlighted the engine vibration....managed to accrue 29 hours SOH on the engine during this time.
Next, I went through the trouble of swapping out the entire engine to see what that would feel like. The other engine ran fine with none of the vibrations that I was experiencing with mine...and that was a 1800 hr. engine had been sitting in a hangar for 15 years, not even pickled!! At that point I knew something was wrong with mine and sent it back to the engine guy. He tore the cylinders off and found scoring on all 4 cylinder walls, really bad scoring on one. He told me that he thought the ring gaps weren't right and that they were expanding too much and scraping the cylinder walls...whatever.
Cylinders were then sent for evaluation by ECI and they determined that it was FOD damage not related to the cylinders, so they won't be covered under warranty. They found: "Foreign object debris damage on piston domes. The damaged spots were up to a 1/4 inch across and .015" deep. The piston skirts also were scuffed, 1 piston had a bent oil control ring and a broken peice of ring land that fell out of the piston after removal"
"Cylinders and pistons were damaged by FOD. The debris was resilient enough to break through the anodized coating on the piston dome. The FOD was not aluminum. The FOD did not come from the cylinders"
"Recommendations-No reason for warranty consideration. Work needed to return to service: Replace all parts, seat guides, piston, valve train. Hone Bore, but it may not clean up"
This is just the cylinders. The bottom end will need new bearings, cam and crank polishing, etc.
Before I learned all this, I had sent them the results from the oil sample from the second oil change (hours 10-25) and it was clean. I took the engine off 3 hours after that oil change and they are claiming that all of this happend during the last 3 hours...of course the engine guy agrees with them so he won't be liable for damages...hes trying to tell me I dropped a washer in the plug hole or something...The only thing i did was install brand new plugs at 10 hours after I realized he put my old plugs back in the engine after overhaul. ( they weren't in that bad of shape but c'mon) I am beyond pissed and I don't know what to do next.
A few things I noticed sometime between all this. In looking at the logs prior to purchase, the engine log stated that this was an "O-320 A2B" engine. i didn't think much of it since that was a common engine model for cubs and never looked at the data plate (stupid me). He overhauled it thinking it was an A2B because thats what the logs said, and even put that in the log entry for the overhaul...apparently he never looked at the data plate either.
I also read here a coulple nights ago that the narrow deck crankshaft has "lightening holes" in the prop flange. Is this correct? If so, my crank has no holes in it (other than where the prop bolts go). Do I even have the right crank in this engine???
Also, I remember him telling me after the first engine run that it "ran good and the oil pressure came up within 6 seconds or so". I wasn't there when he ran it for the first time, but aren't you supposed to "prime" the oil system somehow prior to the first start after a rebuild???
Sorry for being long winded....
The day fianally came where the plane was ready to run. The first break-in flight lasted about 30 mins and for the most part went well. The plane seemed to have excess vibrations but I was a greenhorn cub pilot, so I really wasn't sure what "normal" felt like yet. Plus, the prop had been dynamically balanced prior to the overhaul, and the mech said he didn't mark the prop orientation prior to removal and took all original balance weights off anyway. Tried to fly it home that day but spent an hour flying in some shitty rainy weather trying to make it over the mountains, and couldn't make it home. Eventually got the plane home a few days later.
I was never happy with the engine. It seemed to run well and made good power, but vibrated more than i thought should. Also burned very little oil, and the oil was staying pretty clean. For a while I thought it was the Sensenich prop causing the vibration, seems I always read on here how bad the Sensenich prop was for vibration. Had the prop dynamically balanced, no change. Had the prop checked out by a prop shop, no change. Tried a different prop same model, no change. Each time I'm trying to convince myself that things are improving, but really they weren't. Bought a brand new Borer prop that everyone swears is smoother than the Sensenich. This time I could tell that the prop was running smoother, but since it was so smooth, it really highlighted the engine vibration....managed to accrue 29 hours SOH on the engine during this time.
Next, I went through the trouble of swapping out the entire engine to see what that would feel like. The other engine ran fine with none of the vibrations that I was experiencing with mine...and that was a 1800 hr. engine had been sitting in a hangar for 15 years, not even pickled!! At that point I knew something was wrong with mine and sent it back to the engine guy. He tore the cylinders off and found scoring on all 4 cylinder walls, really bad scoring on one. He told me that he thought the ring gaps weren't right and that they were expanding too much and scraping the cylinder walls...whatever.
Cylinders were then sent for evaluation by ECI and they determined that it was FOD damage not related to the cylinders, so they won't be covered under warranty. They found: "Foreign object debris damage on piston domes. The damaged spots were up to a 1/4 inch across and .015" deep. The piston skirts also were scuffed, 1 piston had a bent oil control ring and a broken peice of ring land that fell out of the piston after removal"
"Cylinders and pistons were damaged by FOD. The debris was resilient enough to break through the anodized coating on the piston dome. The FOD was not aluminum. The FOD did not come from the cylinders"
"Recommendations-No reason for warranty consideration. Work needed to return to service: Replace all parts, seat guides, piston, valve train. Hone Bore, but it may not clean up"
This is just the cylinders. The bottom end will need new bearings, cam and crank polishing, etc.
Before I learned all this, I had sent them the results from the oil sample from the second oil change (hours 10-25) and it was clean. I took the engine off 3 hours after that oil change and they are claiming that all of this happend during the last 3 hours...of course the engine guy agrees with them so he won't be liable for damages...hes trying to tell me I dropped a washer in the plug hole or something...The only thing i did was install brand new plugs at 10 hours after I realized he put my old plugs back in the engine after overhaul. ( they weren't in that bad of shape but c'mon) I am beyond pissed and I don't know what to do next.
A few things I noticed sometime between all this. In looking at the logs prior to purchase, the engine log stated that this was an "O-320 A2B" engine. i didn't think much of it since that was a common engine model for cubs and never looked at the data plate (stupid me). He overhauled it thinking it was an A2B because thats what the logs said, and even put that in the log entry for the overhaul...apparently he never looked at the data plate either.
I also read here a coulple nights ago that the narrow deck crankshaft has "lightening holes" in the prop flange. Is this correct? If so, my crank has no holes in it (other than where the prop bolts go). Do I even have the right crank in this engine???
Also, I remember him telling me after the first engine run that it "ran good and the oil pressure came up within 6 seconds or so". I wasn't there when he ran it for the first time, but aren't you supposed to "prime" the oil system somehow prior to the first start after a rebuild???
Sorry for being long winded....
