O-320 tips

O-320 advice

This is my first post, been reading A LOT about Vans aircraft, on here and everywhere. I took the first step in my build, and it's not the normal first step.

I bought an O-320 E2A out of an old BD4 kit plane. As far as I know the engine was installed new in that plane in 1978. The meter now reads 178.44 hours. The engine last ran 3 years ago.

I'm looking for advice on what to do with the engine, tear it down, borescope inspection, I'm not really sure. But I know there is a wealth of knowledge on this site that will be of great help.

Jared, welcome aboard the good ship VAF

Nothing you can do about the past three years. But for the next 3+ years it will take to get your 9 built, you will need to protect the motor from now on.

When I was confronted with this, I purchased a engine stand from Harbor freight and built a mount for the O320. I capped off the intake and exhaust ports after filling the ports that had closed valves. Filled each cylinder with oil and installed the plugs. Filled the sump 100% and rotated the motor upside down. Used cheap 30wt. oil.

I would have no problem using that motor and just watching the oil screen, filter and compression.

What to do

Congratulations on the first step.

That engine is 150 hp in stock form, it was original equipment on the PA28-140. The horsepower can be increased with higher compression pistons, but it would be fine in a -9 at 150 hp. My E2A has been increased to 160 hp.


There are some AD's on this engine including checking/replacing the oil pump gears.

The main concern with a Lycoming that has been sitting in an unknown state for 3 years and only run 178 hours in 42 years is potential corrosion inside the cylinders and on the camshaft.

The cylinders can be checked relatively easily with an endoscope, so I would at least do that now. If there are no signs of corrosion then it would be worth protecting against further corrosion until the engine is needed. At that future stage I would then get the camshaft checked, as well as any relevant ADs. I don't think I'd spend a bunch of money on the engine just now.

Good luck with it!

170 hours in 40 years means a pretty decent chance that lifter spalling will appear 100 hours into your new plane, if it has not started already. I would probably just overhaul it, as most of the parts won't need to be replaced. Alternatively, I would pull all four jugs. If there is any corrossion on the cylinders, just hone them and install new rings, assuming the majority of the corrossion will clean up with a hone. If not, they can be bored out to address it by a cyl shop. This would also be a good time to install the H/C pistons and thick rods to bump it up to 160 HP. Then carefully inspect the cam lobes. The problem with this approach is that you can only see corrosion on the cam and have a limited view of the lifter surfaces. It would be wise to have a mechanic with a lot of experience to examine the cam/lifters in this approach, as they know what to look for.

As mentioned, there is a good chance this engine has alum impeller gears and they should be replaced.

Better to do this now, before hanging the engine.

Larry

PaulvS said:

Congratulations on the first step.

That engine is 140 hp in stock form, it was original equipment on the PA28-140. The horsepower can be increased with higher compression pistons.

Click to expand...

My old Cherokee 140 had this engine installed and made 150hp from the factory. In fact all O-320's were capable of 150 hp. IIRC, in some early models of the Cherokee the engine was capable of 150 hp but was limited by propeller pitch to 140 hp. These were aimed at the trainer market and may not have had a rear seat. With the right prop it will make 150hp as is. Higher compression pistons could make it 160 hp via stc in the certified world. In the EAB world this and other mods could increase it even more. Some models of o-320 had a different front bearing and it was not recommended to increase hp via hc pistons in these...

https://en.wikipedia.org/wiki/Lycoming_O-320

https://en.wikipedia.org/wiki/Piper_PA-28_Cherokee

Thanks,

Joe

Jslow2 said:

I'm looking for advice on what to do with the engine, tear it down, borescope inspection, I'm not really sure. But I know there is a wealth of knowledge on this site that will be of great help.

Click to expand...

Borescope it and Pickle it now, then decide what you want when your project is ready to fly....a new or used engine.

If you want a new engine or if it fails inspection then get it overhauled when you are nearing completion, not now. (still pickle it thogh) If you want to do flight testing with a used engine, the inspection you perform now will tell you if thats prudent.

There is more than one right answer. Some folks would rather have a safe but generously used engine for flight testing so that they don't have to worry about breaking in a new expensive engine during test flying stage. Some time after the test flight phase is complete, they will get the engine overhauled.

If you measure the distance the the cam lifts each exhaust valve, it might give you an indication of the cam lobe wear.

Thanks for all the advice, I was kind of wary about getting an engine this early, but the price was good so I got it.