What do you think about a Continental 0-300D with 40 years SMOH?

[Tom-D]

If it runs good, it runs good, the chances that you get a few more years out of it with minor expenses is pretty high. If it is blowing by a lot of oil out the breather, you may need a new front crank seal, no worries, they are not an expensive proposition, I had both done on my 310 for $300 some.

You must not be very familiar with the 0-300 in the 170/early 172, when the crank case nose seal leaks, it is all over your windshield not out the breather.

 

[German guy]

[...] Second, if I had the money for a Mooney I'd be all over it. Damn things are fast, and have a nice price point for aircraft that are. That said, you have to be mindful of your mission, what you're going to do when you're done with your IR. I assume you guys are doing this because you want to go places. [...]

You are right about that we want to go places. Actually, we already traveled around the US quite a bit. With the IR we want to make the trips more predictable, as we had to cancel a number of weekend trips, because it was questionable, whether VFR condition will prevail on Sunday, when we had to get back.

This summer, we want to fly to the Yellowstone and the Glacier National Park and also make a trip to New York. So yes - long trips are already on the agenda and not only a possibility in the distant future.

We discussed back and forth whether we should rather get something basic, not too expensive, like a 172 or a PA-28 or if we should spend more and get a sexy Mooney or a Piper Comanche. Actually, I even prefer the looks of a Comanche over a M20C:

Ultimately, we decided however that we'd rather sacrifice speed for the benefit of lower complexity and reduced risk of unexpected expensive repairs. The reduced complexity was actually the main reason to go for a basic aircraft, as both of us are concerned about getting behind the plane, if we fly IFR in a complex aircraft, not to speak of potential gear up landings.

 

[bnt83]

Your silly question has nothing to do with the topic or my attitude towards it. In one thread you whine about deferred minor maintenance issues and in another you advocate running old and tired engines. I really don't care what others think and I wasn't looking to argue about it. I was just sharing my thoughts with the OP. He can consider them, dismiss them, or ignore them as he chooses.

I put a new engine in my Cessna 150 which included a timing advance from 24 BTDC to 28 BTDC and didn't notice much difference. It was a little smoother but I'm not so sure the induction was leaking prior to said work.

 

[James331]

I'd go PA24 all day, they ain't that tuff on mx, I'd wager you'd be much better served.

 

[steingar]

You are right about that we want to go places. Actually, we already traveled around the US quite a bit. With the IR we want to make the trips more predictable, as we had to cancel a number of weekend trips, because it was questionable, whether VFR condition will prevail on Sunday, when we had to get back….
We discussed back and forth whether we should rather get something basic, not too expensive, like a 172 or a PA-28 or if we should spend more and get a sexy Mooney or a Piper Comanche. Actually, I even prefer the looks of a Comanche over a M20C...
Ultimately, we decided however that we'd rather sacrifice speed for the benefit of lower complexity and reduced risk of unexpected expensive repairs. The reduced complexity was actually the main reason to go for a basic aircraft, as both of us are concerned about getting behind the plane, if we fly IFR in a complex aircraft, not to speak of potential gear up landings.

Sure, but the reduced complexity aircraft can break just as expensively and will go slower. I guess my thought is if you have the cash flow to care for and feed the faster aircraft, I'd go for it. Sorry, time is the one thing you can't replace in life. And while I love flying, when I'm in hour four of the trip I'm usually ready to be there.

What I like about the Mooney is the manual gear, which is stone simple and not easily broken. I like the looks of the Commanche as well, but I've always thought Mooney's give a bit more bang for the buck. Just my won opinion, so please don't anyone get their panties in a wad over it. Hey, I like the looks of a Bo better than either.

All that said, I wouldn't worry about getting behind a faster airplane. In most of these, if you back off the throttle they'll go slower. You get your training and do the flying. If I had the cash I'd be all over it. Sadly I don't.

 

[weirdjim]

You must not be very familiar with the 0-300 in the 170/early 172, when the crank case nose seal leaks, it is all over your windshield not out the breather.

But that was the C145/O300A wasn't it? That didn't seem to be a problem with the later versions like the D.

Jim

 

[German guy]

[...] I guess my thought is if you have the cash flow to care for and feed the faster aircraft, I'd go for it. Sorry, time is the one thing you can't replace in life. And while I love flying, when I'm in hour four of the trip I'm usually ready to be there. [...]

I hear you and these were (and still are) our thoughts as well. Actually, we just had another discussion about it - to weigh the pros and cons and to make the right decision is certainly not easy, especially for us a first time buyers.

Most of the time, we do pattern work, poke holes in the sky, go for $100 burgers or do daytrips within 100 - 150 nm. On top of this, I would think that we will, in the average year, do one long +1000 nm trip and maybe two extended weekend trips of 200 - 500 nm, one-way. As nice as it would be to go faster (130 - 140 kts instead of 105 kts) on these three trips, I am really not sure, whether it makes much sense to keep a complex aircraft and all the drawbacks that come with it, just for them!?

 

[timwinters]

Most of the time, we do pattern work, poke holes in the sky, go for $100 burgers or do daytrips within 100 - 150 nm. On top of this, I would think that we will, in the average year, do one long +1000 nm trip and maybe two extended weekend trips of 200 - 500 nm, one-way. As nice as it would be to go faster (130 - 140 kts instead of 105 kts) on these three trips, I am really not sure, whether it makes much sense to keep a complex aircraft and all the drawbacks that come with it, just for them!?

If that's a true representation of your missions then a 172 or 182 should be just fine for you. You could always rent a faster plane for your one or two long XC per year. That'd likely be more cost effective than maintaining the faster more complex plane 24/365.

 

[Tom-D]

But that was the C145/O300A wasn't it? That didn't seem to be a problem with the later versions like the D.Jim

It seems to be a cowl and airflow thing in the 170/172. there is no difference in the nose seals on the whole run of the 0-300.

 

[weirdjim]

It seems to be a cowl and airflow thing in the 170/172. there is no difference in the nose seals on the whole run of the 0-300.

I must have misremembered then. I thought that there was a design change on the seal that gave a lot better life than the stuff that the early 170/172 engines came out with.

Jim

 

[N801BH]

You nailed it. 2500 hour engines don't come apart NEARLY as often as 0.5 hour engines.

Jim

Truer words were never spoken....

If a motor is gonna puke on the dyno,, It will happen on the first pull.....

BTDT dozens of times.......

 

[Stewartb]

Hello everybody,

I am aware that the high lead content of 100LL and insufficient leaning cause the sticking valve issue and that it can be avoided by using mogas and proper leaning. I therefore already conducted some research on where to get mogas ( http://pure-gas.org/extensions/map.html for those who are interested), made sure that Petersen offers an STC (just paperwork, no modification of the aircraft required) and how to safely fuel an aircraft from a can, without blowing myself up.

The Cessna 170 forum as well as Backcountrypilots.org were very resourceful in this regards and also regarding the O-300 engine in general. The many happy O-300 pilots in these and other forums, were also the reason why I was so surprised about the mechanic's negative opinion on this engine type. As I said - other than the manageable sticking valve issue and the lack of power, I could not find anything negative about this engine. Quite the contrary, actually.


When it comes to the overhaul I am, frankly, on the fence. We already factored into our offer that the engine need to be overhauled NOW. We have the money, if it needs to be done, no big deal because this is what we expect. However, now that I slept another night on it , before we actually pull the engine, we will thoroughly inspect it with one of our EAA chapter's mechanics and then make the decision whether we'll have it overhauled right away or not.
Even though I dug even deeper into this topic, I still could not find any reason for failures related to age, other than stiffened polymer parts and possible corrosion issues. I understand that both can be discovered by inspection.

There was also a report in the AOPA magazine a while ago, in which they analysed the relationship between the hours on an engine / its age and accidents. Looking at the result, one should be the more nervous the fresher an engine is:

Source: http://blog.aopa.org/opinionleaders/2014/03/13/do-tbos-make-sense/

In case of 'our' engine (the seller is still thinking about our offer), all cylinders have also been replaced withing the last 20 years, I however don't know whether this means that the cylinder heads were also overhauled at this occasion.

What do accidents have to do with engine reliability? For that matter, if you could filter out engine failures, you'd need to qualify the aircraft use. Ag planes, aerobatic please, etc go through engines quicker. What about 135 airplanes that have to replace or overhaul at TBO time-out? Those stats are absolutely meaningless. If you want to recite rhetoric about more engine failures at low times, recite your own experience. I've only had one engine see catastrophic failure. That motor had 950 hours since new. It spit a rod through the case. I've had others wear out as they approached TBO and topping made no sense. The point is, if you want to apply statistics you need to apply some filters to the numbers and then apply common sense.

 

[German guy]

What do accidents have to do with engine reliability? For that matter, if you could filter out engine failures, you'd need to qualify the aircraft use. Ag planes, aerobatic please, etc go through engines quicker. What about 135 airplanes that have to replace or overhaul at TBO time-out? Those stats are absolutely meaningless. [...]

You might also want to read the article of which I used the graphs and to which I provided a link. :wink2:
The guy who wrote it seems to know what he is talking about, quite a few here apparently share his opinion. I agree with you that the stats for engines past TBO don't say much, because this is when many, if not the most engines get overhauled. Btw., this is also, what the guy who wrote the article said. I think that the message is also not necessarily that the older the engines get, the safer they become, but instead that a new engine or an overhaul carries a pretty significant risk, that the engine might fail shortly after and that an engine should therefore only be overhauled, if something doesn't look right anymore. To replace it, just because 'it is about time' appears to be counterproductive from a safety perspective.

Even though I spent quite some time researching this topic, I still fail to see any reason why an engine which had been overhauled a long time ago (in years) should be more prone for catastrophic failure, assuming there are no corrosion issues or hardened polymer parts. Just take your example with the broken rod - it appears very unlikely that this had anything to do with the number of years it had been in use but, instead with material fatigue or a manufacturing defect. Aren't rods actually re-used anyway and just fitted with new bearing, when they get overhauled?

 

[warthog1984]

The issue is that aircraft engines are routinely run at 75% or higher power settings.

With low hours and high years on the engine, it's an indication that it was run hard, put away wet, and then left to rot.

As an ex-racer who put engines through those hard short cycles, and with a new-to-me engine, I'd be real interested in tearing down that engine and doing an IRAN before trusting it in any situation where loss of power would be critical.

 

[Gsxrpilot]

Since you mentioned a Mooney M20C... I had the very same budget as you a year ago and very nearly the same mission. I bought an M20C with a low time engine and a great IFR panel including 530W, HSI, coupled autopilot, etc, etc, etc.

The M20C with manual gear is very simple and maintenance free. Yes it qualifies as complex but is the least complex of any "complex" aircraft. The Mooney is also one of the easiest IFR platforms to fly. The controls tend to be very "heavy" compared to other light singles. This makes it very stable and really eases the workload in IMC.

It's been said that a Mooney is the best value in aviation (cost to get somewhere) and the M20C is the best value Mooney. Mine does 150kts at 8gph with 1015 lbs useful.

It's my first airplane and I was a low time pilot with only about 10 hours IFR. It's much easier to fly IFR than the trainers I learned in.

Just my $0.02

 

[Tom-D]

Aren't rods actually re-used anyway and just fitted with new bearing, when they get overhauled?

Yes they are re-used, but they are checked for defects such as cracks, then they get straightened and the upper end re-bushed and honed to piston pin size, then the lower end gets shaved and bolted together and honed to perfect size to give proper clamping of the bearing shell.

Simply replacing the bearing is building a short life engine, because the lower end gets oval in service. the top end bushing wears too.

They also get new bolts and nuts.

 

[German guy]

Yes they are re-used, but they are checked for defects such as cracks, then they get straightened and the upper end re-bushed and honed to piston pin size, then the lower end gets shaved and bolted together and honed to perfect size to give proper clamping of the bearing shell.

Simply replacing the bearing is building a short life engine, because the lower end gets oval in service. the top end bushing wears too.

Very interesting. Thank you.

 

[Tom-D]

Very interesting. Thank you.

I rebuild these engine to new standards.

 

[Checkout_my_Six]

amazing what a fresh coat of paint will do.....

 

[N801BH]

amazing what a fresh coat of paint will do.....

Yup.... Nuttin better then a top of the line Krylon overhaul.......

 

[kyleb]

Yup.... Nuttin better then a top of the line Krylon overhaul.......

Are you supposed to install the Engine Rebuild in a Can before or after you paint it?

 

[Tom-D]

amazing what a fresh coat of paint will do.....

aesthetics are a big part of making the owner smile. but they won't smile long with out 6 new cylinders, reworked cases, cam, lifters, and crankshaft.

 

[Tom-D]

Yup.... Nuttin better then a top of the line Krylon overhaul.......

OBTW that engine was Dupont Imron.

 

[Stewartb]

I used Imron on my last engine build. Variprime underneath. It's held up very well. All parts machined to new tolerances, rods balanced, crank ground and balanced, case align bored, new Titans, new cam. What do you other guys do when you build one? I don't agree with everything Tom writes but his engine building comments are solid in my book.

Two questions for Tom. Do you use plasti-gauge to verify bearing clearances? What product do you use to seal the case?

 

[N3368K]

I don't agree with everything Tom writes but his engine building comments are solid in my book.

^^^THIS

I would happily fly any engine he's gone through.


Jim R
Collierville, TN

N7155H--1946 Piper J-3 Cub
N3368K--1946 Globe GC-1B Swift
N4WJ--1994 Van's RV-4

 

[Tom-D]

I used Imron on my last engine build. Variprime underneath. It's held up very well. All parts machined to new tolerances, rods balanced, crank ground and balanced, case align bored, new Titans, new cam. What do you other guys do when you build one? I don't agree with everything Tom writes but his engine building comments are solid in my book.

Two questions for Tom. Do you use plasti-gauge to verify bearing clearances? What product do you use to seal the case?

Pictures are better than words

the case seam, I use a thinned coating of #2 non harding permatex on both sides, let it set over night to stiffen up. then place a single strand of 3 pound test monofiliment line as you would #50 silk thread. bolt together, torque, re-torque after 24 hours. be certain you get a good squeeze prior to putting the cylinders on.
Never ever under any circumstances put any thing on your main bearing mating surfaces.

 

[Tom-D]

Keep in mind, the new Lycoming engine cases have an "O" ring groove. put nothing execpt a little petrol jelly to hold the "O" ring in place while you mate the cases.

 

[Tom-D]

I must have misremembered then. I thought that there was a design change on the seal that gave a lot better life than the stuff that the early 170/172 engines came out with.

Jim

If you are talking about the old stretch it over the prop flange vs the new split seal, yes there is a difference. They produced a replacement to the old seal because few could install the 1 piece with out destroying it.

 

[Stewartb]

Pictures? I used an imron gray that was close to Lycoming gray. It hides grime better than bright paint jobs. The PA-12 that it went into was a ground up rebuild. New airframe, short engine mount, as many Supercub parts as could be adapted. Great plane. I sold it to a good friend a couple of years ago.

 

[Tom-D]

Pictures? I used an imron gray that was close to Lycoming gray. It hides grime better than bright paint jobs.

OMG you don't allow your engine to get dirty do you?

 

[Tom-D]

Pictures? I used an imron gray that was close to Lycoming gray. It hides grime better than bright paint jobs. The PA-12 that it went into was a ground up rebuild. New airframe, short engine mount, as many Supercub parts as could be adapted. Great plane. I sold it to a good friend a couple of years ago.

Nice bird. is that belly pod a tank or baggage? or half and half?

 

[weirdjim]

If you are talking about the old stretch it over the prop flange vs the new split seal, yes there is a difference. They produced a replacement to the old seal because few could install the 1 piece with out destroying it.

The trick I was taught by an old greasy is to put the old 1 piece in a warm (NOT HOT) oven for a couple of hours to let it soften up before you carefully pulled it over a greased flange. That seemed to work OK.

Jim

 

[Stewartb]

OMG you don't allow your engine to get dirty do you?

At every opportunity. There's little that makes me smile like a stripe of mud under each wing and a coat of mud on the tail. The spring days are about to produce some of that but for now I'm off to work on a K Factor issue. The only way to do that is to go burn avgas. Cheers.

 

[Tom-D]

The trick I was taught by an old greasy is to put the old 1 piece in a warm (NOT HOT) oven for a couple of hours to let it soften up before you carefully pulled it over a greased flange. That seemed to work OK.

Jim

I used hot oil, smoking hot oil, and the proper tool, but those who try the old screwdriver trick always ruined them.

 

[Stewartb]

Nice bird. is that belly pod a tank or baggage? or half and half?

Firmin Pod, now called Alaska Bush Pod. A very difficult field approval when I did it. It keeps cargo weight centralized under the wing. The cabin has a full length flat floor and huge baggage area but a pod is much easier to reach.

 

[Tom-D]

Firmin Pod, now called Alaska Bush Pod. A very difficult field approval when I did it. It keeps cargo weight centralized under the wing. The cabin has a full length flat floor and huge baggage area but a pod is much easier to reach.

This one was a half and half.

This is a project that was completed a few years ago.

 

[Tom-D]

Firmin Pod, all cargo.

 

[Stewartb]

Sorry, yes, all cargo.

 

[Henning]

The issue is that aircraft engines are routinely run at 75% or higher power settings.

With low hours and high years on the engine, it's an indication that it was run hard, put away wet, and then left to rot.

As an ex-racer who put engines through those hard short cycles, and with a new-to-me engine, I'd be real interested in tearing down that engine and doing an IRAN before trusting it in any situation where loss of power would be critical.

percent power alone is irrelevant, you have to compare %HP/CuIn. If your engine is rated at .5hp/CuIn you can make full power full time, as long as you have adequate cooling, you will cause no more appreciable wear and tear than if you throttle back.

 

[iflyvfr]

Tom, very nice & clean engine. What is that for, some uninstalled engine accessory?