See William Wynne's Article on his Website HERE.

Storing a Complete Engine – Notes from William Wynne on How to Do This Properly


Some of the most frequently asked questions are about storing a completed engines. The following notes cover these topics.

How long can an engine sit after it was assembled without being damaged? Indefinitely, as long as it is protected from moisture and corrosion. Look at the engine above, proof that your Corvair is great, but it isn’t capable of understanding calendar time. If it is stored properly, it would have no issue waiting 50 years to be started.


If we do a break in run on my engine at a college, do we have to treat it with preservatives or something before it gets stored? No, this isn’t an issue. At Colleges, we run engines on unleaded fuel for a very specific reason: The byproducts of the combustion of Avgas are corrosive in the presence of moisture. If you run an engine on 100LL and then store it in a less than dry atmosphere, it will attack the combustion chambers and seats. Unleaded auto fuel does not do this. During the break in run we keep the oil temp way above the boiling point of water, and it boils out the entrained water, and coats the inside with oil. If it gets sealed up as it is cooling off, the engine is set to be stored, as is. I do not drain the oil. If I cut open the filter, I replace it with another, or seal it with a small plastic bag.


What about ‘Fogging’ the engine like people do with outboards in the fall? Not required. Because many outboards have open exhausts in the lower end that lead right to the cylinder bores, fogging is a good idea, but you are not going to keep your Corvair outside like most boats are kept over the winter. Outboards face condensation issues even if you wrap them with tarps. I have fogged Corvairs in the past, but I do have some question about the compatibility of our rings with fogging, and since there isn’t a need for it, we don’t do it.


What about dehydrator plugs? You don’t need them. They are a good idea on aircraft engines which are still stored on the airframe, but you are not doing this, you are putting your masterpiece indoors.


What is the right way to store it? First, put four ‘feet’ on it, these are made from four 1/2″ x 4″ carriage bolts and eight 1/2″x13 coarse thread nuts. You put these through the four mounting points in the bottom of the case, and they prevent the weight of the engine from sitting on the pan. Then tape off the six exhaust ports, the two intake tubes, and the two breather ports. Seal up all the oil ports and the filter area. Put the entire motor in a very thick (8mill) Clear plastic bag.


Catch why the bag has to be clear: Just before you close the bag, you put in a 4″x 4″ piece of mild steel sheet, completely stripped of all finish, either sand blasted or wire wheeled clean and bare. You put this on top of the engine, in the bag, where you can see it at a glance walking by. This way, six months later, if you notice that the plate has rust forming on it, you know you need to reseal the bag, move the engine or both. If the bag is a dark color, you will not be able to see it until it is too late. Even though this makes a lot of sense, I have done it this way since before the first Gulf War, many people will just wrap it up in a blue tarp and put it in the pool shed, because their better half didn’t like the idea of putting it under the glass coffee table top in the living room.


On the day that was going to be the glorious moment where the pristine test run masterpiece was to be unveiled and mounted on the equally magnificent airframe of craftsmanship, and Horrors! Some evil-doer has taken your tribute Tonawanda and replaced it with a rusty, corroded artifact from Robert Ballard’s warehouse! Don’t let this happen to you. Store your masterpiece properly.