Edsel

DrPappy

DrPappy

Pre-takeoff checklist
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DrPappy
I found a 172N that I was interested in, but after some reading I have found that the O-320-H2AD is apparently the "Edsel" of the 172 engines. :( Apparently it likes to eat camshafts and lifters. The engine has had been factory remanufactured...would this still present the same problems as the original?
 
DrPappy said:
I found a 172N that I was interested in, but after some reading I have found that the O-320-H2AD is apparently the "Edsel" of the 172 engines. :( Apparently it likes to eat camshafts and lifters. The engine has had been factory remanufactured...would this still present the same problems as the original?
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It also has the twin mag which has intermittent parts availability issues. The question lies in when the FRM was done. If it is in current use and not exhibiting problems, I would not dismiss the deal on the current evidence. Flight schools would operate them to between 3&4000 hrs without cam problems because they were operating 1000 hrs a year. It wasn't until GA usage slacked off that the cam problems started showing up.
 
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All the Lycoming O-300 series engines eat camshafts and lifters. It really sucks, but it is what it is. An important question on a prospective purchase of this plane is, how much has it flown since the reman? How was the plane stored and in what climate? The cam problem comes from rust formation on the camshaft. The solution is to fly a lot, change your oil more frequently and use Camguard. Hangaring and a dry climate help too.
 
Henning said:
It also has the twin mag which has intermittent parts availability issues. The question lies in when the FRM was done. If it is in current use and not exhibiting problems, I would not dismiss the deal on the current evidence. Flight schools would operate them to between 3&4000 hrs without cam problems because they were operating 1000 hrs a year. It wasn't until GA usage slacked off that the cam problems started showing up.
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I think the owner said it has been flown around 50-60 hours since he bought it 2 years ago, and it has been hangared since at least then. It has less than 1000 hours TTAF. Both of these seem to indicate it has pretty much been a hangar queen, which apparently is especially bad for the H2AD.
 
Dav8or said:
All the Lycoming O-300 series engines eat camshafts and lifters. It really sucks, but it is what it is. An important question on a prospective purchase of this plane is, how much has it flown since the reman? How was the plane stored and in what climate? The cam problem comes from rust formation on the camshaft. The solution is to fly a lot, change your oil more frequently and use Camguard. Hangaring and a dry climate help too.
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2 minor things, first Lycomings never made an O-300, and that the issue exists regardless. The statement is correct, I just didn't want him to get confused thinking that it may not apply to something because it wasn't a certain number.
 
The H2AD suffix indicates the small lifter, single mag drive variant.

Not long into the life of the engine it developed problems with cam spalling, and lifter damage. Several field repairs were offered, but finally an AD was issued changing the lifters out for better ones. Also, the engine case can be modified to use the older lifter design and some of them have been so modified(I think it's boring out the lifter boss). If it's been modified, the logs should reflect that modification.

The single mag drive in the acc case has come under fire for being a single point of failure. But really, if you get down to it, the mag drives are all driven by the crank or cam(more often) and there's only one crank and one cam, so it's a SPOF that's really not a big deal. However, it does add one more SPOF for the mag drive.
 
Henning said:
2 minor things, first Lycomings never made an O-300, and that the issue exists regardless. The statement is correct, I just didn't want him to get confused thinking that it may not apply to something because it wasn't a certain number.
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He said " Lycoming 0-300 Series" that includes a number of engines made by Lycoming.
 
DrPappy said:
I found a 172N that I was interested in, but after some reading I have found that the O-320-H2AD is apparently the "Edsel" of the 172 engines. :( Apparently it likes to eat camshafts and lifters. The engine has had been factory remanufactured...would this still present the same problems as the original?
Click to expand...

Read every thing you can about the "T" modified cases for the H2AD engine, that pretty much cured the lifter problem.

BUT

you still must pre-heart at a higher temp than most engines and use oil complying with the Lycoming AD on this engine.
 
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docmirror said:
The single mag drive in the acc case has come under fire for being a single point of failure.
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That is a perceived conception that is a worry for a lot of folks but never had a failure rate to warrant the reputation.

the factory has stopped supporting the unit, but there are plenty of A&Ps and mag shops still rebuilding them. The parts issue will not present itself until the on the shelf parts run out.
 
DrPappy said:
I think the owner said it has been flown around 50-60 hours since he bought it 2 years ago, and it has been hangared since at least then. It has less than 1000 hours TTAF. Both of these seem to indicate it has pretty much been a hangar queen, which apparently is especially bad for the H2AD.
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No, you are mixing issues and making some incorrect assumptions due to reading incomplete advice.

First off, what climate is it in? Coastal v Desert is a huge difference.

Keeping a plane in a hangar is a good thing, 1000hrs TTAF is a very good thing, also a 2 year old FRM will have a roller cam upgrade, not the same engine you are reading about. 50-60 in 2 years is low, but certainly enough that with proper general care the engine could be just fine.

Number and words are just that, data. Not until you combine the data with inspected condition though does that data become meaningful.

When I'm looking for planes for people, the ones that have Ben hangared all their lives go to the top of the list to inspect, because experience tells me they will be in much better condition.

Here's the main thing though, you are putting too much value on the engine. The engine is the last consideration because engine upgrades carry the highest residual value at sale.

What you are looking for is a clean airframe. Airframe repairs are expensive and extremely time consuming. Planes being down over a year for them is common. If I found a clean 172 airframe with a H2AD on it, I wouldn't walk away. I would look at the overall condition of the engine and if it was running well I wouldn't be particularly concerned, and would buy a spare mag when a deal came around to have on hand.

If it was not running well, I'd look at what the Penn Yann 180hp ones are selling for and try to bargain accordingly to making that upgrade. (IOW, I'm not going to try to knock the price of the upgrade from their asking, rather take the price of the upgrade off an upgraded comp to determine my offer).

Airframe is paramount also because any airframe repairs in the logs detract from market value.

Find clean airframes, out of those choose the one with the avionics you want, and bid it with regards to the engine it has. Engines are quick and cheap to replace. If you prearrange it, it can be done in a week, and it adds nearly dollar for dollar the engine cost (you lose labor) to the value of the plane which prorated down to 75% TBO where it maintains a 'Core Value' regardless of hours.
 
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Tom-D said:
That is a perceived conception that is a worry for a lot of folks but never had a failure rate to warrant the reputation.

the factory has stopped supporting the unit, but there are plenty of A&Ps and mag shops still rebuilding them. The parts issue will not present itself until the on the shelf parts run out.
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Agreed, I have not seen it as significant concern. Just find a spare to have and you're good.
 
DrPappy said:
I think the owner said it has been flown around 50-60 hours since he bought it 2 years ago, and it has been hangared since at least then. It has less than 1000 hours TTAF. Both of these seem to indicate it has pretty much been a hangar queen, which apparently is especially bad for the H2AD.
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This case is where I would advise this engine be disassembled cleaned and inspected, prior to running.
 
Tom-D said:
This case is where I would advise this engine be disassembled cleaned and inspected, prior to running.
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50-60 on a roller cam engine? This is a 2 year old FRM engine, I thought that Lycoming had been switching out all the bottom ends.:dunno:
 
Henning said:
Agreed, I have not seen it as significant concern. Just find a spare to have and you're good.
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The engine in this case has sat inactive for too long for me to be comfortable with the condition of the single impulse coupling not to be rusted. It is located high in the accessory case where all the condensation occurs. To me, this is the major soft spot for the H2AD.


It isn't much comfortable having a spare in your baggage compartment when it fails in the air, and drops debris into the accessory case.
 
Tom-D said:
The engine in this case has sat inactive for too long for me to be comfortable with the condition of the single impulse coupling not to be rusted. It is located high in the accessory case where all the condensation occurs. To me, this is the major soft spot for the H2AD.


It isn't much comfortable having a spare in your baggage compartment when it fails in the air, and drops debris into the accessory case.
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It's a 2 year old SFRM with 50-60 hrs on it from what I read.:dunno: Do you consider that sitting inactive?

Never mind I read something wrong and confused it with another thread.
 
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Henning said:
50-60 on a roller cam engine? This is a 2 year old FRM engine, I thought that Lycoming had been switching out all the bottom ends.:dunno:
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This is not a roller cam/lifter, and no Lycoming does not support it any longer, you send it into the factory for overhaul, you will get the replacement engine. (Forget the Designation)
 
Sounds like the best effort for this particular engine would be a teardown, mag drive inspection, lifter bore mod to bigger lifters, and then gasket and seal replace. Then, you'd have a well known mill to hang on there. Sadly, that would likely destroy any savings by buying the engine at a discount.

Nothing in life is free.
 
Tom-D said:
This is not a roller cam/lifter, and no Lycoming does not support it any longer, you send it into the factory for overhaul, you will get the replacement engine. (Forget the Designation)
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Yeah, I read it wrong and confused two deals. I would just deal this one figuring a Penn Yann conversion and make it into what a 172 should be.
 
docmirror said:
Sounds like the best effort for this particular engine would be a teardown, mag drive inspection, lifter bore mod to bigger lifters, and then gasket and seal replace. Then, you'd have a well known mill to hang on there. Sadly, that would likely destroy any savings by buying the engine at a discount.

Nothing in life is free.
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This is one of the Lycomings that the lifters can be removed and inspected and you can see the cam.

But

When inspected, if every thing did not look brand new, I'd tear it all the way down. just for my warm and fuzzy feeling.
 
My history with the H2AD, I supported one for over 10 years for the use of it. I did all the annuals and maintenance on it. I pulled the mag for inspection every 100 hours or at annual ( the aircraft did fly 100 hours per year) and every time I pulled it, the impulse coupling was rusty. I'd clean it up, replace the spring, wash out the accessory case, change the oil, pull all the lifters inspect and replace, and in the 10 or so years that I did this never found a problem with the cam/lifters.

the year after Istopped using the aircraft it was sold to a Canadian and was exported to BC. the next year it flew 20 hours, and the impulse coupling failed and the aircraft and owner were lost between Vancouver and Vancouver Island.
 
One thing I noticed is the add says 430w but the pic shows a 430 non WAAS. There is a difference in both a few thousand dollars, and vertcal iguidance on approach, value difference.
 
Seventy thousand dollars for a 40YO Cessna 172 with a troublesome engine design?

Gulp. If it were me, I'd buy two old Bonanzas for that price and have money left over. One plane to fly(faster, more load) and one for parts.
 
If I had a client looking for a 172 I would be booking a plane ticket to see it in person.

You never know until you look at the plane. Pictures lie, log books tell a politicians version of truth at best. The airplane tells the truth.

This plane has all the ear marks of being a good plane, that is more important than being the cash purchase deal. If you have a premium airframe, it is always going to pay back in spades a small premium in price in the long term.
 
Tom-D said:
... the next year it flew 20 hours, and the impulse coupling failed and the aircraft and owner were lost between Vancouver and Vancouver Island.
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What do you mean by "failed"? Did it fail to decouple after the start or did it just come apart?
 
docmirror said:
Seventy thousand dollars for a 40YO Cessna 172 with a troublesome engine design?

Gulp. If it were me, I'd buy two old Bonanzas for that price and have money left over. One plane to fly(faster, more load) and one for parts.
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Hey, I hear you. 172's are just something I am familiar with--aviating, not tearing apart. Sure, I could find an aircraft for 1/2 the price, but I want something that is reliable and doesn't need a spare aircraft for parts! I am admittedly not much of a mechanic for anything beyond spark plugs or an oil change. That is why I was willing to pay more if it were a reliable aircraft. With that in mind, it sounds like I need to keep looking.
 
kgruber said:
There is no way to tell from the picture. Even a converted GNS430W just says GNS430 on the faceplate.
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Ok, I thought they changed the face, I saw now come back that way a while back. I would certainly verify full function on the test flight.
 
FWIW, the original H2AD in my '78 C-172N went 1527 hours before it was swapped out for a different 0-SMOH H2AD in 1981. That one went 1843 hours and 17 years SMOH, and was still doing fine when it was replaced with an O-360-A4M (Air Plains STC).

I don't have the logbook for the first engine, so I can't tell you what prompted the overhaul at 1527 hours.

The conventional wisdom about H2ADs is that they don't handle cold climates well. This airplane was based at Truckee CA (5900' MSL) from new to 1988, so it had its share of cold.
 
Silvaire said:
What do you mean by "failed"? Did it fail to decouple after the start or did it just come apart?
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I only know what transport Canada said.

It failed.
 
As always, I'll disclaim any knowledge of Cessna, but my goodness, if there are 5000 C-172s for sale, why bother with the H2 engine? Get something older or newer and pay less? Knowing what I know about the Porsche 996 engine foibles, those cars are discounted accordingly. Any plane with that engine should be far, far lower in my very humble opinion.
 
docmirror said:
As always, I'll disclaim any knowledge of Cessna, but my goodness, if there are 5000 C-172s for sale, why bother with the H2 engine? Get something older or newer and pay less? Knowing what I know about the Porsche 996 engine foibles, those cars are discounted accordingly. Any plane with that engine should be far, far lower in my very humble opinion.
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Total time and condition.. = Value.

as seen by most buyers.
 
docmirror said:
As always, I'll disclaim any knowledge of Cessna, but my goodness, if there are 5000 C-172s for sale, why bother with the H2 engine? Get something older or newer and pay less? Knowing what I know about the Porsche 996 engine foibles, those cars are discounted accordingly. Any plane with that engine should be far, far lower in my very humble opinion.
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Because engines are the lowest loss value components on the plane. If you have a super clean low time airframe, I don't care if the engine is trash as long as I can buy the airframe correctly so I can do a 180hp conversion. If I was buying a 172 I would be wanting a nice clean one like this hoping I can core value the engine on the deal, because I would want to do the 180hp conversion.
 
Tom-D said:
You don't see a difference between 1 thousand hours and 8000 hours?
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I do. But I don't see that much value diff. Particularly with the H2 engine. Meh - it's just me.
 
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