Lycoming 320 question

[Steve]

Whats the difference between the O-320 E2D and E2H ? Is either better than the other?

 

[VNugget]

http://www.prime-mover.org/Engines/Lycoming/Lyc_Cert_list.html

-E2H: Same as -E2D but equipped with S4LN-20 and -21 Mags.

 

[Steve]

Thanks Vnugg,

Can anyone with experience working on these engines chime in ? I've heard that the E2D is preferred over the E2H bt can't figure out why.

 

[Lead Sled]

It sounds to me like you’ve really got a question about the 0-320 powered C-172. In 1968 Cessna switched from the 6-cylinder 145 hp Continental 0-300 to the 4-cylinder 150 hp Lycoming 0-320-E2D. This was an 80 octane engine. In 1977 they switched again to the 160 hp, 100 octane O-320-H2AD. As always, it was a case of good news, bad news. The good news was 10 additional horsepower, an increase in service ceiling (and high density altitude performance) and a slight increase in speed. This was overwhelmed by the bad news, which reduced to its simplest form is poor lubrication of the valve train. This is particularly noticeable in cold weather. It was found that cold starts could cause terminal damage very quickly, with large metal contaminants introduced to bearings, oil pump and other critical components in short order. It also had the "2 in 1" mag. Not my favorite setup. I had one fail that resulted in a total loss of power and an off-field landing.

There are three major ADs on the H2AD engine - AD 77-20-7 calls for replacement of the tappets, AD 78-12-8 calls for replacement of the oil pump impeller, and AD 78-12-9 (the big one) mandates replacement of the crankshaft. If the ADs have been it’s probably an OK engine, but personally I'd probably opt for the 80 octane engine and run autogas. In 1981 Cessna changed to the O-320-D2J.

‘Sled

 

[TrafficInSight]

H2AD engines are good engines these days, the only thing about them is that you need to run 100plus oil or straight 100 with a Lycoming additive.

Most FBO's carry 100plus so it's really not a problem.

And the dual mag is pretty reliable too now that the kinks have been worked outl although, as Led Slead noted, something going wrong with the drive mechanism means losing both mags and an off airport landing.

 

[Steve]

It sounds to me like you’ve really got a question about the 0-320 powered C-172. In 1968 Cessna switched from the 6-cylinder 145 hp Continental 0-300 to the 4-cylinder 150 hp Lycoming 0-320-E2D. This was an 80 octane engine. In 1977 they switched again to the 160 hp, 100 octane O-320-H2AD. As always, it was a case of good news, bad news. The good news was 10 additional horsepower, an increase in service ceiling (and high density altitude performance) and a slight increase in speed. This was overwhelmed by the bad news, which reduced to its simplest form is poor lubrication of the valve train. This is particularly noticeable in cold weather. It was found that cold starts could cause terminal damage very quickly, with large metal contaminants introduced to bearings, oil pump and other critical components in short order. It also had the "2 in 1" mag. Not my favorite setup. I had one fail that resulted in a total loss of power and an off-field landing.

There are three major ADs on the H2AD engine - AD 77-20-7 calls for replacement of the tappets, AD 78-12-8 calls for replacement of the oil pump impeller, and AD 78-12-9 (the big one) mandates replacement of the crankshaft. If the ADs have been it’s probably an OK engine, but personally I'd probably opt for the 80 octane engine and run autogas. In 1981 Cessna changed to the O-320-D2J.

‘Sled

Thanks Sled,

Exactly what I was looking for. If the H2AD was overhauled after 1992 should these AD's apply to it?

 

[Lead Sled]

If the H2AD was overhauled after 1992 should these AD's apply to it?

I would assume so, but don't count on it. You always need to do a thorough pre-purchase inspection of the engine airframe and logbooks. Find a good unbiased mechanic to do it and pay him what he asks. It will be the best money you've ever spent - especially if he turns up something that makes you want to back out of the deal. Whatever you do, don't fall for the old "We just annualed it a couple of months ago - it passed with flying colors!" Also, one more bit of advise... Set aside an amount equal to at least 10% of what ever you pay for it to cover those inevitable things that alway seem to pop up after you buy an airplane. Trust me, you're going to need it.

'Sled

 

[avbug]

Never make an assumption on AD's. Check.

The dual mag single drive installation isn't better today; it's what it always was; failure prone. I have two dead friends who found out about that the hard way.

The oil impleller replacement was universal through all the series, going aluminum to steel. The crank issue was widespread, but if you're buying a newer engine, this shouldn't be an issue. Ensure that AD is complied with. You don't want to get caught up in the expense of splitting the case.

Yes, valve train issues are endemic to the lyc series...get a preoiler, and do away with that (at least for start up).

 

[Dave Danger]

"Referencing the O-320-H2AD engine AD that addresses the lubrication issue"
Guys, there is no guarantee that even the "T"-mod is a solution for the lifter/camshaft lubrication problem either. I recently pulled a low compression cylinder on a FACTORY NEW engine with less than 500 hrs, and found that several lifters (with the heavy duty tappet body) were brinelled and pitted and making enough metal dust to support the mining industry of a small 3rd world country. (Can you sing the Lycoming Song? "Remove and ship and split the case.. doodah..doodah.."). On the other hand, I have a customer with the exact same engine, field overhauled about 7 years ago... pushing about half-life, with no problems at all.

Not trying to generate work here, since I'll probably never see a single one of you guys at CSG, but a pre-purchase is worth every penny. Even if you do it several times for a couple of different planes. If absolutely nothing else it can provide you with bargaining leverage on a price that's maybe a tad steep. I try to obtain a complete photo-copy of the logbooks before the plane ever arrives at my location. I'll usually spend upwards of 8 hours sometimes researching the maintenance history and AD compliances. When the plane actually arrives for a visual insp.. I already have a very good idea what condition it's in, and what to look for.

Dave Danger