Lycoming O-320 Overhaul vs Replacement

[High Wing Drifter]

I'm trying to ascertain what sort of cost/benefit I would get from a Lycoming O-320 (AA5-A) zero timed overhaul as opposed to a replacement. We still have a few hundred hours to go but forewarned is forearmed and all that.

Anybody have any ballpark figures, experience or nuggets of wisdom to empart? I have this notion that a factory replacement would be in the region of £15k all in. Is that realistic?

Another related question is how long would one expect the aircraft to be out of action?

All comment/opinions welcomed.

Cheers,
HWD.

[Yankee]

If you are going for a replacement engine in your AA5 please take the following into consideration. The standard 0-320-E2G is a 150hp unit, which can only be exchanged via Lycoming for another 0-320-E2G. You might well want to consider taking the opportunity to upgrade your engine to 160hp, which is CAA approved http://precisionengine.home.mindspring.com/4plstc.htm with higher compression pistons giving you much improved T/O and climb performance, one of the few failings of the AA5. This upgrade can only be done by O/H of your existing engine as it is a STC, which Lycoming will not recognise as an exchange option.

[High Wing Drifter]

Thanks Yankee,

I got your PM too. Much appreciated. The 160hp is an option, although known about, seemed problematic. Is there anywhere in the UK to get STC done?

Cheers,
HWD.

[Yankee]

No problem getting this done in the UK, Cabair have had a few done as well as at least two AA5 Travelers that I know of. Will send you a PM as don't want to be seen advertising on here.

[Tall_guy_in_a_152]

We recently replaced the O-320 in our PA28-140 and took the opportunity to upgrade from a 150 to a 160hp unit.

Lycoming charged an extra £800 for an "unlike core exchange".

Total cost including fitting was a little over £12000. Engine was shipped direct from the US.

Total time aircraft offline could have been as little as one week, except that we stopped flying early due to a safety concern. The old engine has to be delivered to Belgium for onward shipping to the US.

Ours is the third PA28 in the UK to have the mod (much better than being the first!).

[Yankee]

I believe, and I’ll willing to be corrected, that the reason Lycoming will except the 150hp in exchange for a 160hp engine on the PA28 is because both engines are standard types produced by Lycoming. As far as I’m aware there is not 160hp derivate, off the shelf engine, available of the 0320-E2G which can be fitted on a AA5 engine mount

[High Wing Drifter]

Thanks for you input Tall Guy. Its a pity that Lycoming sound so pinickity over the issue. It can't be beyond them to provide a factory STC service!