Oil Filter Options

DG624 · 07-03-2003, 12:36 PM

Does anyone have experience with Oberg or other filters on a 911? I had one of these on a GTI which worked great but the 911 engine compartment seems a little too cramped. I like the horizontal mounting and the elimination of the mess when cleaning the filter (no oil drips into the negine compartment). I also think there was some cooling benefit plus no paying for new filters. Is there any other system that would be similar?

Formerly Steve Wilkinson · 07-03-2003, 01:15 PM

I've got one in the attic. Bought it but never installed it after Steve Weiner advised me not to. Not enough filtering action, as I remember. (It was a couple of years ago.) Drag racers love them because they catch all the trash after an engine blows and are easy to clean, but they're not as effective as good paper-element filters. Having said that, I must admit I had a similar one in my airplane--a Capehart--and I'm still alive...

Stephan

DG624 · 07-03-2003, 01:40 PM

The filter I have (GTI) has a 28 mircon screen which is much better than the paper filters. That car has 165,000 and still has good compression. It also had a warning light that lets you know when to clean the filter. I am tired of the mess in the 911 engine compartment. I don't know if there is enough room but I will investigate. I was wondering if the 20 GPM flow rate was adequate for the 3.2 L?

DG624 · 07-03-2003, 01:42 PM

Steve,

If you still have the filter are you interested in selling it?

Formerly Steve Wilkinson · 07-03-2003, 02:53 PM

28 microns better than a paper filter? I don't think so... Also, understand that "28 microns" refers to a microscopic BB, spherical and theoretically perfect. The screen will stop that. But what about the 280-micron-long sliver that's 20 microns in diameter? It won't necessarily stop that while a paper filter will. Theory sometimes differs from reality.

Stephan

Geary · 07-04-2003, 08:09 AM

I have seen this "long sliver" argument in one of the oil filter manufacturer's advertisements. Which one is it? It was specifically thought up as an answer to Oberg & System 1 filters, which use an aerospace stainless mesh as a filtering medium. In reality, I don't know that slivers 20 micron in diameter exist, although larger diameter slivers certainly do.

The fact remains that paper element filters (although they brag about very low micron ratings) bypass a very large percentage of the oil ALL THE TIME --- especially at higher RPM or when the oil is cold. The oil cannot possibly all pass through the paper. Cold start-ups are the worst, because any chunks that aren't embeded in the paper are quickly blown through the bypass, headed straight for your main bearings.

Not a single pro drag race team will use a paper element filter, even those with a huge "FRAM" (or whatever) plastered on the side because they offer so little protection from chunks recirculating through the bearings. They all use System 1 filters --- which happen to spin right in place of the paper element filters used on 911s, offering true full-flow protection.