Considering a used O-320 narrowdeck - What should I know?

[Loman]

I have come across a used O-320 engine for sale and I am interested in it for my RV-9 build. I can't see how I can ever afford a new or factory re-built engine and it is very tempting to get an engine that works at a reasonable price.

I am very new to aviation so I really don't have the knowledge to assess this properly. I would appreciate any advice that you guys have to offer.

I know from independent sources that this is a good and reliable unit, which has given 7 years of great service on a Lancair and is now being swapped out due to an upgrade to a 200hp engine. The engine is an O-320 A model. I don't have the full designation and I suspect that may not be very relevant for an engine of its age that has been changed a lot. It is a NARROWDECK of 150hp with a low compression set-up. It is fitted with Lightspeed ignition. Unusually, the mount is a Dynafocal. The bottom end was completely rebuild 600 hours ago and the heads were reworked 450 hours ago. In both cases the machining was outsourced and the owner rebuilt the engine himself. A new carb was added 450 hours ago. There is currently a slow oil leak which is probably the main seal. I doubt that there is a complete log available.

From reading previous posts on narrowdeck O-320s, I see there are different opinions on parts availability and cost, conical mounts seem to be a problem and there is a lot of discussion about hold-down plates. This issue seems mainly to relate to conversions to a high-compression 160hp set-up in which I have no interest. Apparently,these engines are lighter, which does interest me.

Included is an exhaust (to suit a Lancair), carb, baffling and oil pre-heater. The price is $8k. Other posters have said that narrowdeck O-320 cores should go for about $5K but maybe the extras make up for this.

Am I crazy to be thinking of this? What factors should I consider?

[Mel]

This engine should be fine for the RV-9. As far as price goes, if you are happy and the seller is happy, that's all that counts.
Actually a good used engine is best for a new airplane. A new airplane needs a totally different flight regime than a new engine. A new engine needs to be run hard for the first few hours. That's NOT what a new airplane needs!
I wouldn't count on the exhaust system fitting the RV.

[osxuser]

The narrow deck cylinders cost about $100 more a piece when overhaul time comes around (not a huge factor). Since the engine is older, you might have to deal with more fatigue issues down the road. Other than that, it sounds like a pretty good deal. $8K for a mid time engine (what you describe) seems reasonable to me.

[pierre smith]

You're left with 1400 hours or more....that's 15 years of flying for most folks!

Considering that it's a running engine means that it's a known quantity that you can bolt on and go fly....sounds good to me.

Best,

[AX-O]

I also purchased a mid time 320. It was a B2B (160 hp) with 1200TT and 300 STOH. A few issues I have encountered during my build.

-If you buy a Sam James engine plenum, it won’t fix no matter what anyone says. You have to make it fit.
-If you want to update it to fuel injection in the future, it will be a little more difficult. Most old cylinders don’t have provisions for primer port and fuel injection. They only have provisions for primer ports. Also the brackets for the spider won’t fit.
-If you want to update the oil sump, you will have to buy additional parts for oil pick up, screen, etc..
-Vans Baffles did not fit quiet right.
-Check that the engine complies with all SB. I had to remove a couple of parts from my oil filter assembly.

I got a few others but they were self inflicted due to my own mods. Hope that helps.

By the way I paid $5,500 and it came (out of an RV-4) with everything necessary to drop it into my RV-4 if I wanted to do so (carb, mags, pipes, prop, prop extension, oil cooler, baffles, etc..). I choose not to.

[caryr]

I wouldn't afraid of the term 'narrow deck'

the newer engine is 'wide deck'

the differences are small.

Look at the base of the cylinders. If its just studs with nuts, its wide deck. If it has a piece of metal or bracket between studs on the same cylinder, then its 'narrow'

The actual base of he cylinders is alittle bit different.

[jrs14855]

The older engines are likely to have lightening holes in the crank flange. I would not want to do acro with a metal prop with the lightening hole flange. Mild acro with a wood prop should be ok.

[N208ET]

I don't know if this applied to the narrow deck 320, but on my narrow deck 360 when it was orginally made, they didn't put enough dowel pins between the two case halves which could lead to case fretting. My engine was made in the 60's and either at the last overhaul which was 94' or before that, more dowel pins were machined into the case. Might be worth looking in to.

Randy
8A inspection done

[Danny King]

A used engine is a mystery, period. Unless you put all the hours on it over the years, and you supervised all the maintenance, then you really have NO idea what this engine is. Logbooks must be considered pure fantasy! The only way to determine what you have there is to completely disassemble the engine and have all the components tested and checked by a competent shop.

If the engine is cheap enough, and you can handle a possible expensive disappointment, then proceed.

I know engines are expensive, but the engine is the heart of your new airplane. You will be trusting your safety, and that of your passenger to that engine. Ask yourself this question: Would you buy a bran new car with a used engine?

I recommend that you consider building one of ECI's 0320 kit engines made from new TSO parts. The difference in the long term cost might surprise you!

[ArVeeNiner]

Originally Posted by Danny King

A used engine is a mystery, period. !

I bought a B2B that was running and attached to an airplane. I saw it run. I had a friend who is an A&P look at it. I have yet to fly it but it saved me a ton of dough.

What difference would it have made if I had bought that engine AND the plane it was attached to? I certainly wouldn't feel compelled to throw that used "mysterious" engine away for a brand new engine. The plane I owned before building an RV was a 1951 Aeronca Sedan with a 1951 prop and engine and it gave me 6 years of great fun.

So yea, there is a risk but a smaller risk than buying a used engine AND a used airplane too which is done all the time. This was the only way for me to get into the air with my budget. Now, if I were wealthy, no question, brand new all the way.

True, we don't buy a new car and slap a used engine on it but after all the battle scars my "new" plane has on it already, it could be considered used by the time I fly.

I'm not sure what conical mount problems you've read about but I've NEVER flown a plane before where I actually knew what kind of engine mounts it had. I just didn't really care. I've read where Dynafocal's are supposed to be smoother than conicals but hey, we're building airplanes, not Cadillacs!

Good luck!