Engine failure of sorts in my Bravo--need advice on what to do

[Bravoman]

9 hours ago, LANCECASPER said:

Highly doubtful that they'll take it as a core (Section A, point 4 on the service letter below):

 

lycoming service letter 250.pdf

We are waiting to hear back from Airpower, the authorized distributor. My MSC sent photos and other info and Airpower is in turn talking to Lycoming. I have my fingers crossed. I'll report back when we know, hopefully this week.

[jclemens]

Divco has that case in stock for $6500.00 outright, if you wanted to repair what you have and keep flying.  I bet the major internals are fine. 

[Bravoman]

2 hours ago, jclemens said:

Divco has that case in stock for $6500.00 outright, if you wanted to repair what you have and keep flying.  I bet the major internals are fine. 

Thanks for that, I agree as well  that the internals are probably generally ok. If lycoming refuses to give me core credit it will likely be my only viable option.

 

Thanks again, Frank

[steingar]

By Odin, if my engine ever barfs up a windshield full of oil I might have to "forget" to lower the gear on the way back!

[Bravoman]

3 hours ago, steingar said:

By Odin, if my engine ever barfs up a windshield full of oil I might have to "forget" to lower the gear on the way back!

She got me back alive and in one piece. I didn't want to scratch her belly quite in that fashion!

[Bravoman]

 Just got word that Lycoming is excepting my core. The only penalty, if you will, is that I do not get the approximately $5000 discount that they offer on factory remans for a first run engine.  All in all, I am pleased with that outcome. 

 

Regards, Frank

[Bravoman]

Edit above: accepting my core( that's Siri for you!)

[Guest]

If you go with a factory engine will it come back as a roller tappet engine?

Clarence

[Marauder]

If you go with a factory engine will it come back as a roller tappet engine?

Clarence

Are roller tappets considered bad or good? I'm hearing both.

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[Bravoman]

27 minutes ago, M20Doc said:

If you go with a factory engine will it come back as a roller tappet engine?

Clarence

 It is my understanding that the factory remans come with the roller tappets. I will get clarification on that. I am awaiting the paperwork from airpower on all of the particulars. 

[DonMuncy]

In theory, roller tappets are the only way to go. In reality, I have no idea.

[KSMooniac]

I personally think roller tappets are a solution looking for a problem that does not exist in aircraft engines.  They really shine in high RPM applications with aggressive cam lobes, which are not present in our Lycomings.  

I think the cam distress is a result of a combo of poor metallurgy, some corrosion, poor lubrication, and extra mechanical stress from sticky valves.  Lycoming could address each of those problems without roller tappets.

Note that the roller tappets are mandatory replacement items every time the case is split, so the cost of overhauls and even teardown inspections will go up for these engines.  That can potentially raise the insurance rates for all of us if there is a couple AMU extra charge every time the case is split.

For Bravoman, I wouldn't argue with going for a factory exchange in this case since you won't be subject to a bunch of unknown extra costs dealing with this cratered engine.  You'll also get back in the air sooner too, so that is nice.  I hope it works out very well.

[FoxMike]

Last I checked roller tappets were not on the menu for the TIO 540 AF1B.  Number of engines was too low for Lyc to certify the engine with them.  Maybe they changed their mind but I kinda doubt it.

[Yooper Rocketman]

I installed roller tappets in my big block Chevy of my 1969 Chevelle the last time I did serious engine work and in less than a couple thousand miles one failed and now requires the engine to be pulled so I can get it out without destroying the block.  I found this out this summer when trying to get it going for my weekly ice cream runs, and didn't have time to do that much work to get it fixed.  I know not "apples to apples", but I never had a standard cam and lifter combination fail that soon and cause so much work to fix.  Not sure I would be real excited about that combination in my airplane engine.

[Steve Dawson]

On 1/19/2016 at 1:27 PM, KSMooniac said:

FWIW I did a careful field overhaul of my 360 when I lost a cam lobe, including overhauling my first-run cylinders.  The only downside IMO is the downtime vs. a factory exchange.  I'm very happy with the engine we built and feel we got a smoother, better-balanced engine than Lycoming spits out of the factory.  All of the rotating components got precision balanced, lifters got flow-matched, and the cylinders got flow-balanced as well.  Lycoming just takes parts out of the bins and assembles...  Minimizing vibration is one of the keys to longevity for the engine as well as many airframe components and instruments/avionics.  

Just out of curiosity Scott, did you notice much improvement in power and did balancing the crank/rods/piston assemblies also help out for smoothness?

Edited January 27, 2016 by Steve Dawson

[KSMooniac]

Well, I don't think I'm thru the break in completely but it is definitely smoother. I haven't done a dynamic balance yet but I'm looking forward to measuring where it is currently. I'd be very surprised if it could be improved.

Power wise, I'm not sure yet. I think it is better but my down time was exceedingly long so I lost my calibration. I haven't flown at my usual cruise altitudes yet so I'll have to report back later.

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[jetdriven]

5 hours ago, Marauder said:

Are roller tappets considered bad or good? I'm hearing both.

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What failures of you heard of roller tappet engines? OTOH we get reports here weekly of flat tappet cam failures.

[jetdriven]

3 hours ago, KSMooniac said:

I personally think roller tappets are a solution looking for a problem that does not exist in aircraft engines.  They really shine in high RPM applications with aggressive cam lobes, which are not present in our Lycomings.  

I think the cam distress is a result of a combo of poor metallurgy, some corrosion, poor lubrication, and extra mechanical stress from sticky valves.  Lycoming could address each of those problems without roller tappets.

Note that the roller tappets are mandatory replacement items every time the case is split, so the cost of overhauls and even teardown inspections will go up for these engines.  That can potentially raise the insurance rates for all of us if there is a couple AMU extra charge every time the case is split.

For Bravoman, I wouldn't argue with going for a factory exchange in this case since you won't be subject to a bunch of unknown extra costs dealing with this cratered engine.  You'll also get back in the air sooner too, so that is nice.  I hope it works out very well.

I think regarding rolling vs sliding tappets, there is a clear winner here, unless the added complexity of roller tappets subtract from reliability more than they add, and I dont think so. Ive had a dozen cars, for example, with roller cams and tappets and some had over 200K miles, and often sat for a half a year before driving, but I've never lost one.  And I cannot seem to find any evidence of a roller cam failure in an aircraft engine either.

[Bravoman]

 I have confirmed with the rep at Air Power that roller tappets are not included with this particular engine. I  inquired why, and he indicated that it was not part of the engineering design for the TIO 540 for the bravo.  He began to explain the reasons to me, but it is way above my pay grade. 

 

 From What I am seeing thus far, Air Power  is a very good company from a customer service perspective.

 

Regards, Frank

[jetdriven]

if roller tappets arent part of the deal,  the factory is the absolute last place I'd have my engine done. Well, the next to last place, Custom Airmotive put the wrong size engine bearings in an engine owned by a friend of mine, and refused to honor the warranty, since it was a whole 13 months old and 50 hours since OH.

Anyways, I'd take the 6500$ hit on the case and have Zephyr overhaul it. My factory engine is covered in rust and peeling paint, my other friend's Comanche 260C, with an engine overhauled a year before mine by Zephyr, looks new.  But thats just looks, Zephyr can build an engine. And even with new cylinders, theyre a lot less expensive.

Edited January 27, 2016 by jetdriven

[Shadrach]

So my question is a simple one. If the internals are fine, and they were good enough before the case cracked, why is the whole engine suddenly in need of replacement?

Why not just buy a case reassemble the engine and enjoy another 1000hrs. People burn themselves out of aviation doing things that won't make their planes safer, faster or more reliable. I think a "factory new" engine is a poor choice. There are any number of engine shops in the south that could split the case and assess exactly what happened and what needs to be replaced.

[jetdriven]

Factory new is like 96 grand.

[Shadrach]

1 hour ago, jetdriven said:

Factory new is like 96 grand.

And how much does a "Frankenreman" cost?

[LANCECASPER]

31 minutes ago, Shadrach said:

And how much does a "Frankenreman" cost?

http://www.airpowerinc.com/productcart/pc/engines.asp?searchParm=TIO540AF1B&catID=33

 

[Marauder]

5 hours ago, Marauder said: Are roller tappets considered bad or good? I'm hearing both.

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What failures of you heard of roller tappet engines? OTOH we get reports here weekly of flat tappet cam failures.

My question is whether they are good or bad to have. I hear people say they are not needed and cause issues. Just never understood if any of it was true. Roller tappets were not installed on my last OH and when the time for the next one is due, I'd like to know. How long have they been used on the IO-360 series?

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