CJ Rader
Pre-takeoff checklist
I had one of those. Had a supercharger on it.. 100 extra ponies would hit right when VTEC-yo kicked in. Kinda like setting off a JATO unit from 6000 rpm onward.. Fun car.
My engine fell out
- Thread starter Salty
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mscard88
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A supercharger on that thing. Wow. I had a Miata then bought the S2000, what a difference 100 more hp was, let alone a supercharger for another 100!
CJ Rader
Pre-takeoff checklist
350 HP at the crank. It was ferocious. ...And a little scary in the corners with that much oomph on tap. Went from that to a BRZ, to a 370Z, back to a BRZ (that I supercharged), and now a 2002 Miata SE because it's cheap to operate and leaves room in the budget to fly planes.
mscard88
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Yeah you can't beat a Miata, fun car to drive and bulletproof. Had mine for 11 years, 99 model, then Honda came out with the S2000 in 2000! If I had only known lol.
96-09-10 is probably the AD that was not complied with properly. The part that seems to always get missed is the 5 year replacement after the date of the issuance of the AD, which would have required replacement in the early 2000s. A review of the engine records would be necessary to make anything more than an educated guess though.
Salty
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I found this in the logs
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I’m not going to spend my time researching ADs for your engine but I interpret the AD differently. More history would really be needed to ascertain the status. If you care, read the AD and research it yourself. The fact that your mechanic is stating the pump needs to be replaced due to AD implies that he knows there is one that applies.
Salty
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It's moot now, since it will all be replaced to comply, but I'm not seeing how that AD did not apply. I'm in contact with two of the IA's that have done annuals on the plane, I'll ask them how they came to the DNA conclusion.
Probably because they failed to see the 5 year part of the AD.
Indeed it’s moot, but there was another thread started a while back that has a common theme...
Part C doesn’t seem to exempt them. You likely have an aluminum pump gear and that only notifies you that you don’t have a sintered iron gear.
PaulS
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Salty, you should play a lottery ticket because that engine was a failure waiting to happen. Glad you are getting it fixed.
Salty
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Well, after another couple of months of reading SB's and AD's, I finally understand that this one was not applicable to my engine. The AD did not make that clear, but the SB was more obvious.Probably because they failed to see the 5 year part of the AD.
Indeed it’s moot, but there was another thread started a while back that has a common theme...
Part C doesn’t seem to exempt them. You likely have an aluminum pump gear and that only notifies you that you don’t have a sintered iron gear.
I've had a lot of difficulty sourcing some of the parts, but I finally have everything and am ready for assembly.
I've done a lot more than I expected, and being that the engine was so old there were a large number of SB's that needed compliance, there was a lot more that had to be done than I knew going in. Basically I'm going for a "like new" in front of the firewall overhaul. If I couldn't make the part "like new" with an overhaul, I bought a new one.
That includes the prop governor, prop hub, mags, carb, new cylinders, camshaft, followers, hydraulic plungers, mag drive gears, and more.
It's been quite a learning experience already and we haven't even started assembly yet.
PaulS
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Pics Salty, lots of them through the process please. Thanks for sharing.
N659HB
En-Route
Shiny!
Salty
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I was hoping less than 20k. But I seriously extended the scope, and raised the budget to 30k. The prop was 7k and the engine monitor 3k, so that explains that.
If I’d done a bare bones “use all I can” (like the cylinders could have been overhauled) and just counting the engine, not accessories, I could have done it for about 13k.
I will go a bit over the 30k, but not significantly. I’ll save more from not flying it for the 4 months than I went over.
PaulS
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Lol, a potential aircraft owner!
dell30rb
Final Approach
You definitely needed an overhaul. Thanks for posting.
A borescope would have shown the pitted valves... a quart every 5hrs is excessive and did you get an oil analysis done? Probably would have shown the cracked rings.
I am curious how this would have gone from the "Mike Busch" inspection standpoint. My guess is that cylinders would have been pulled due to borescope + oil usage + oil analysis results, and lead to the discovery of the bad cam and cracked rings which would have motivated you to do a full overhaul at that time.
A borescope would have shown the pitted valves... a quart every 5hrs is excessive and did you get an oil analysis done? Probably would have shown the cracked rings.
I am curious how this would have gone from the "Mike Busch" inspection standpoint. My guess is that cylinders would have been pulled due to borescope + oil usage + oil analysis results, and lead to the discovery of the bad cam and cracked rings which would have motivated you to do a full overhaul at that time.
1RTK1
Pattern Altitude
I "believe" for that engine Lycoming considers oil consumption up to 1 qt. per hour.
PaulS
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Hmmm borescope could have shown those worn cam lobes too. Do people turn the engine when inspecting with a scope?
Salty
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Not without pulling a cylinder.
Dav8or
Final Approach
What?? Please explain how you can use a bore scope to inspect the cam lobes on a Lycoming. Loads of us would love to hear of this secret technique.
PaulS
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No secrets, just think outside the box a little.
When at least one plug is removed from each cylinder the engine will turn relatively easily. When you turn the engine, slowly in this case, by the prop maybe, with a borescope properly placed in the cylinder pointed at the valve, you should be able to see the valves move (this means open and close). That cam looked like it had an eighth of an inch worn off one of the lobes, that means the valve would open an eighth of an inch less than it should, easy to see especially relative to the other valves which looked like the lobes weren't as worn. Seems to me Salty or his mechanic might have seen the difference had they done this when he suspected problems saving him some angst as he decided whether to open the engine or not. I don't know if some one has thought of this before, seems like a good idea to me.
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MooneyDriver78
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Tom
This is how my mechanic figured out his cam was bad, he didn’t even need the borescope, taking off the head gaskets you can measure valve movement. I believe there is an adjustment you can make and doing so it became apparent he had a problem.
bnt83
Final Approach
If it’s a fixed pitch prop there is a good chance it can be scoped through a plug in the end of the crankshaft. I did mine that way. I was able to feed the scope all the way through it and see each lobe, unfortunately the rods get in the way when trying to turn the crankshaft to see the apex of the cam lobes furthest away. It’s not easy to get a great view of those but you can still get in there and see a more than I thought possible.
A constant speed equipped lycoming will have an additional plug in the crankshaft that cannot be replaced without engine disassembly.
KRyan
Pre-takeoff checklist
Is that prop new, or "new to you?" Only asking because it has the "old" logo stickers on them that haven't been used for about 8-10 years now.
PaulS
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There you go, that's a more accurate way of doing it, a little more invasive but still pretty simple, just remove the valve covers. I'm thinking should I ever get a low hour low usage older engine I'd probably ask for something like this at annual, it's a pretty simple check. Water under the bridge for Salty, but it would've made the open it up decision much easier for him.
Dav8or
Final Approach
Ok, it the lobe is totally trashed then maybe this technique would work, but the typical Lycoming camshaft spalling happens with little change in the cam profile for quite some time. They just make lots of flakes in the filter. The only way to tell for sure is pull the cylinder, or I guess keep running it until the lobe gets knocked way down and then use the bore scope.
idahoflier
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idahoflier
Per Lycoming SB 480F the max oil consumption formula for direct drive engines is: 0.006 x BHP x 4 ÷ 7.4 = Qt./Hr.
PaulS
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The argument there will be to run it if it is spalled unless there is a catastrophic failure mode. The issue with the spalling is the hardened layer is destroyed exposing metal that wears much quicker. The borescope could find bad cases like this one. Popping the valve covers and measuring the valve actuation could find much more subtle wear. Honestly I haven't thought too much about it because I don't own, but someone could make some bucks selling Inspection equipment for things like this.Ok, it the lobe is totally trashed then maybe this technique would work, but the typical Lycoming camshaft spalling happens with little change in the cam profile for quite some time. They just make lots of flakes in the filter. The only way to tell for sure is pull the cylinder, or I guess keep running it until the lobe gets knocked way down and then use the bore scope.
Dav8or
Final Approach
So I guess Lycoming says for the engine that is the topic of this thread, that .58 quarts of oil per hour is the max oil consumption. In simple terms, if you find yourself adding a quart every two hours, you are at the max before you have to do something.