I recently read some info from Lycoming, oil companies, and other engine experts on preventing engine corrosion. It's my understanding that everything on the combustion side of the piston gets a glaze that slows down the start of corrosion for a few weeks. The area where moisture is a more immediate problem is on the cam because oil film is not held in place on the lobes.

After reading this and doing some research on available products I came up with the conclusion that there's a nitch to fill. There are forced air crankcase dryers that require access to electricity that start in the $300 range but nothing for the guy who keeps his plane in a barn or under a tarp on the tarmack. I'm making a crankcase dryer that a pilot can take off the engine during preflight and put it back on after landing as easly as taking off the oil cap and it doesn't cost an arm and a leg. If your interested click on my website, http://www.casedry.com, or see my add in barnstormers.
http://barnstormers.com/cat.php?PHPSESSID=7c8385cc003c14ca1fbfba548d7f7397
Chad Wirsig.

Oops, sorry about the comma--fat fingers.

I realize that FAA approval only means it was demonstrated to do no harm by the FAA. Point is, see if you can find that for MMO or any of the other additives.

Again, read the results of the research.

What REALLY surprised me, though, was talking to the major engine guys about the stuff. Both Lyc and Continental reps said, kind of grudgingly that they'd looked pretty carefully at the test results, and that they have to agree that the stuff may have some benefits. This is virtually a glowing recommendation in this liability driven world, in my opinion.

MTV

Anyone heard of or used Microlon? Sounds like a similar product to the Cam Guard and is also FAA approved. My IA is a big advocate, but even though he has loads of knowledge and experience I remain skeptical of snake oil additives. If it or the Cam Guard were worthwhile I would try one, but worthwhile seems to be a pretty subjective assessment.

http://www.microlon.com/

Check out the Detroit letter under the test data tab at microlon. They said they ran an engine 2-1/2 hrs w/o oil without any problems. Amazing if it's true.

They do make impressive claims, but so do all the bottles on the shelf at AutoZone (no, I'm not putting any of those in my plane either!). Does the FAA approval carry any weight? ~$200 for a one-time application would be cheap insurance, if it truly did make the difference in getting you back to the field with no oil or oil pressure.