Double Whammy

[Velocity173]

Today I got the double whammy on the Velocity. Georgia personal property tax statement came in at $902.16. I don't mind paying my taxes though since the cost of living here is quite cheap. What hurt today was my mech saying I need an overhaul. I've got metal in the filter, the oil sample came back with high amounts of metal and when he did the run up my compressions: 71,73,68,50. He said the number 4 cylinder has either a stuck valve or a burnt valve. My engine just sat for too long. 900 hrs and needs an overhual. I suppose 16 yrs since the last one with not enough use will do that. Oh I should have just kept renting.

 

[denverpilot]

Or could have let someone fly it for the price of fuel while you were unavailable, which is probably cheaper than an engine.

Hard to know who to trust though. And insurance issues.

Bummer man.

 

[dell30rb]

Or could have let someone fly it for the price of fuel while you were unavailable, which is probably cheaper than an engine.

Hard to know who to trust though. And insurance issues.

Bummer man.

I flew a 152 owned by an acquaintance while he was deployed in africa for 6 months - 1 yr.

I paid him for a year's worth of full coverage insurance (as a named insured pilot on his policy) before he left so he had piece of mind that the airplane was fully insured. IIRC he came back early due to a family issue and kicked me back some of the insurance money.

Then I paid him $25 per hour (hobbs) for maintenance. I sent his wife a check at the end of each month. The airplane did have two maintenance issues while he was gone which totaled about $450 and he reimbursed me for them. The local A&P who he was familiar with did the work.

It worked out very well for both of us as he pocketed a few hundred bucks (even after repairs) the plane was flown about twice per week and it was actually running better when he got it back thanks to the repairs.

IIRC the hourly maintenance budget was figured on the 2400hr tbo and 17k overhaul and then a 3k per year annual misc maintenance cost divided by 200 hrs per year

 

[taters]

Not saying that its not time but is the metal coming from the bottom end of the engine or cylinder (s)? Ive seen engines go along damn way with re-tops...but if that metal is nickel coming of the cam etc...well that it...that surely makes for a crappy day.

 

[hindsight2020]

Replace #4, IRAN the rest. That's what I would do with 900hr engine. When you mean it sat too long, what does that mean? Like a whole year without running?

 

[Velocity173]

Not saying that its not time but is the metal coming from the bottom end of the engine or cylinder (s)? Ive seen engines go along damn way with re-tops...but if that metal is nickel coming of the cam etc...well that it

Yeah my A&P is saying the metal is pointing to piston ring/cylinder wear. Maybe a top is the way I'll go. He quoted me for 26 grand on a IO-360 overhaul. It's a really reputable shop but I think I could find someone else cheaper.

 

[hindsight2020]

Not saying that its not time but is the metal coming from the bottom end of the engine or cylinder (s)? Ive seen engines go along damn way with re-tops...but if that metal is nickel coming of the cam etc...well that it

Naive question. Are the cams something that could be replaced without the expense of a bottom overhaul or is it considered a false economy? I don't think it would be on an engine with 900hrs, assuming the source of metal could be pin-pointed. For all we know that #4 is just coming apart and a simple jug repair/replace would make the perceived problem go away.

 

[Velocity173]

Replace #4, IRAN the rest. That's what I would do with 900hr engine. When you mean it sat too long, what does that mean? Like a whole year without running?

Yeah I bought it directly from Velocity. It sat for about 6 mths before they picked it up. It sat at Velocity for another 6 mths before I bought it. It flew 700 hrs in its first 5 yrs (good). Then it it flew for only 200 hrs in the last 10 yrs (bad). Oh yeah the biggie, engine logs were lost and they start from 2001. I would just feel a whole lot better with a good overhaul pushing me along. :wink2:

 

[Keith Lane]

Get a price from Charlie Melot. He is on here pretty frequently. Never a bad word about him.

http://www.zephyrengines.com/homepage.html

 

[dell30rb]

Replace #4, IRAN the rest. That's what I would do with 900hr engine. When you mean it sat too long, what does that mean? Like a whole year without running?

Since you have one cylinder that is really way below the rest I'd do this as well. Have them all pulled and inspected.

Bottom ends are tough. I would never do this to an aircraft engine (DISCLAIMER) but I got a free jet ski that had ingested salt water two years ago and both cylinders were seized. I beat the pistons out with PB blaster, block of wood and a sledge. Bought oversize pistons and had the cylinders bored and matched by a machine shop. Only thing I did to the bottom end (which did not move entirely freely, but no visible corrosion) was flush it out with a gallon of WD-40 and turn it by hand till it moved with no resistance. Slapped it back together, rode it for three years and it was running great when I sold it.

 

[taters]

Ya check around 4 rebuilt cylinders should be had for a decent price
heres 2 http://www.ebay.com/itm/LYCOMING-CY...iation_Parts_Gear&hash=item2eb3c18419&vxp=mtr $400 per cylinder not bad.

 

[taters]

Naive question. Are the cams something that could be replaced without the expense of a bottom overhaul or is it considered a false economy? I don't think it would be on an engine with 900hrs, assuming the source of metal could be pin-pointed. For all we know that #4 is just coming apart and a simple jug repair/replace would make the perceived problem go away.

It can be buy If a case has to be split to that extent an OH is worth it at that point imo

 

[timwinters]

For Cylinder(s).

Seth Record.

Performance Aircraft Powerplants.

Pap2fly.com

He does impeccable work.

 

[AdamZ]

Get a price from Charlie Melot. He is on here pretty frequently. Never a bad word about him.

http://www.zephyrengines.com/homepage.html

I've always felt Charlie gave good straight forward answers on the forums. He has a good rep and while I don't have a plane, Ted has sent both of the 310's engines to zephyr engines for OH and Ted knows engines.

 

[wabower]

Mike Busch discusses this subject frequently on many websites including his own Savvy aviator site. He says cylinders are accessories, repair or replace the bad one and keep on trucking. If cam is spalled or other issues dictate, a major could be in order but I wouldn't do it unless it was absolutely necessary. If you can lay hands on a CPA magazine (Cessna Owners) I think last month's issue contains one of Mikes articles that is directly on point with your situation.

 

[JHW]

Yep, an engine is just a bunch of parts. If a part breaks and it's accessible, fix it. If a wheel bearing does bad you don't throw up your hands and complain "time to overhaul the airplane".

But if you do need an OH why not do it yourself ? I overhauled my O-360's for about $12.5 each, including new cylinders and sending out the machine work. It takes time but there's not much else to do in central IL during jan-feb, too cold to work outside, too warm to have a snowmobile.

 

[Morne]

Yeah I bought it directly from Velocity. It sat for about 6 mths before they picked it up. It sat at Velocity for another 6 mths before I bought it. It flew 700 hrs in its first 5 yrs (good). Then it it flew for only 200 hrs in the last 10 yrs (bad). Oh yeah the biggie, engine logs were lost and they start from 2001. I would just feel a whole lot better with a good overhaul pushing me along. :wink2:

Are you saying that you only fly 20 hours a year? Maybe renting is better?

 

[wabower]

Hey Bubba, how's the paint job holding up?

Yep, an engine is just a bunch of parts. If a part breaks and it's accessible, fix it. If a wheel bearing does bad you don't throw up your hands and complain "time to overhaul the airplane".

But if you do need an OH why not do it yourself ? I overhauled my O-360's for about $12.5 each, including new cylinders and sending out the machine work. It takes time but there's not much else to do in central IL during jan-feb, too cold to work outside, too warm to have a snowmobile.

 

[Tom-D]

I wouldn't even look at them twice, I'd pull them, place them in a box and send them to Zepher hills Fl.

and be ready to write the check.

 

[JHW]

Hey Bubba, how's the paint job holding up?

costing me some fuel as I find myself deviating around rain i would have flown through before. But it's holding up well, and I'm glad we did the sheet metal work to remove the leftovers from the drogue chute and other engineering gear that beech never saw fit to take out.

 

[Tom-D]

Mike Busch discusses this subject frequently on many websites including his own Savvy aviator site. He says cylinders are accessories, repair or replace the bad one and keep on trucking. If cam is spalled or other issues dictate, a major could be in order but I wouldn't do it unless it was absolutely necessary. If you can lay hands on a CPA magazine (Cessna Owners) I think last month's issue contains one of Mikes articles that is directly on point with your situation.

The fallacy of Mike's opinion is that you will have an engine with unbalanced out put, thus you get one that will go putt, bang, putt, bang. and you will have the cowling off about every time you turn around.

 

[wabower]

His experience is quite different. When he conducted his seminar in Dallas, one of his engines had ~2700 hours, the other slightly less. What method do you use to measure relative output for each cylinder?

The fallacy of Mike's opinion is that you will have an engine with unbalanced out put, thus you get one that will go putt, bang, putt, bang. and you will have the cowling off about every time you turn around.

 

[Tom-D]

His experience is quite different. When he conducted his seminar in Dallas, one of his engines had ~2700 hours, the other slightly less. What method do you use to measure relative output for each cylinder?

I've run a lot of test cells with vib meters, bmep gauges, you can see the advantages of having even BMEP across all cylinders, I have seen the results of engines that get new cylinders in 1 or 2 places that have more frequent gyro changes, and flight control hinges that wear more with engines that don't run smooth.

You may not feel it, but your aircraft does, these engines were made to run as smooth as possible, It's my contention that the smoother these engines run the better.

 

[jsstevens]

I've run a lot of test cells with vib meters, bmep gauges, you can see the advantages of having even BMEP across all cylinders, I have seen the results of engines that get new cylinders in 1 or 2 places that have more frequent gyro changes, and flight control hinges that wear more with engines that don't run smooth.

You may not feel it, but your aircraft does, these engines were made to run as smooth as possible, It's my contention that the smoother these engines run the better.

Tom,

Does that mean if you see significantly different numbers on a compression check that you'd rebuild the engine or replace the cylinders to get the engine smooth again? How different would the numbers have to be to concern you?

John

 

[Tom-D]

Tom,

Does that mean if you see significantly different numbers on a compression check that you'd rebuild the engine or replace the cylinders to get the engine smooth again? How different would the numbers have to be to concern you?

John

Each engine must be judged on its own merits.

This engine may or may not need a complete overhaul, it would depend upon what type of metal it produced, My fear would be that the metal went to the crank/cam bearings and running it will ruin the lower end.

As far as the cylinders are concerned, I'd do all 4, Bite the bullet get it over with.

 

[Velocity173]

Are you saying that you only fly 20 hours a year? Maybe renting is better?

No I fly about 75 hrs a year. I also have a Glasair that I fly about 75hrs a year. Doesn't make economical sense to have two planes but whatever, I likes to fly.

Problem is she sat on the ramp at Sebastion FL in a very corrosive environment for about 6 mths. It sat on the ramp in another FL airport for about 6 mths as well. The few years prior to that it didn't fly all that much either. Of course lack of use is bad for an engine. Thankfully the airframe is mostly composite so the only metal I had to replace was some of the hardware on the outside. Wing attachment bolts still looked good. What I can't believe is how those people down in FL fly those metal rust buckets safely, but that's for another forum.

We all have heard the recommendation to overhaul every 12 yrs. I've never really agreed with that but in my case I think it applies. I'm not sure the last overhaul (1997) was a thorough one and having the aircraft not being used just wasn't good for this engine. We'll see, maybe I can get away with just a top and IRAN the rest.