Fwiw
FWIW, I started using Kelly Aerospace oil filters on my RV-7 (switched from Champion) back in April. Like you, I'm interested in saving a few dollars here and there as long as it's not at the expense of my engine.
The photo above shows the Kelly filter element versus the Champion filter element. First of all, the Kelly filter uses a "leaf spring" in the can instead of a coiled spring. The Kelly also has an integral metal lip/bushing in the filter element instead of using a plastic bushing. I don't think these differences are significant. The real difference is in the pleats. The Kelly has fewer pleats, and they're not as "pretty" as the Champion. Where the Champion filter element's pleats are nice and neat, even all around, the Kelly's are less precisely aligned.
Here's another view of the Kelly filter element. Is it a big deal that the filter element isn't as pretty as the Champion's? I don't personally think so. Is it a big deal that there are fewer pleats? I don't think it makes much difference. Maybe if you let the oil go for like 100 hours or more, or if your engine was making lots of metal, I guess I could see the value in having more surface area. But that's definitely not the case with my plane. I change the oil frequently, and the engine doesn't make any metal (at least not today). So I've decided that the Kelly oil filter is fine for my application, and I'm gonna continue using it and saving a bit of fuel money.
What's very interesting to me is that the first oil analysis taken after switching to Kelly showed a marked drop in several elements. This is either coincidental or related...I don't know for sure. All I can say is that otherwise
nothing else changed in terms of the operating conditions, the way I operated the plane/engine, etc. (NOTE: I switched from using Hobbs time to tach time on the 3rd analysis)
I'm about to take a new oil analysis at the next oil change. We'll see if the trend (values lower than when using a Champion filter) continues. I seriously doubt the oil filter has anything to do with it, but you never know! Maybe cheaper is better in this case? (Probably not, I wager they're basically identical.)
)_( Dan
RV-7 N714D (670 hours)
http://www.rvproject.com