I am an ex USAF jet engine and turboprop specialist and have always built all of my personal performance engines, Cleveland Fords mostly.
So I might know a thing or two.
If it is a defective filter problem it would be hard to diagnose if it was a random defect in the filter. A bike that has sumped would need to have the filter flow tested if indeed such a flow test rig is available.
HD should look into that.
Any bike that sumps, have the filter sent in for testing to determine its functionality.

 

Yeah well , i’m A chicken hawk!

 

I stayed at a Holiday Inn last night.

 

now that's funny

 

Chandler,

Check this diagram.

https://www.hdforums.com/forum/milwa...l#post15655377

If the oil filter clogged up, filter would go into bypass mode, to continue pressure feeding the engine the oil it needs.

 

Same filter used on the Twin Cams without sumping.

 

You guys are hilarious, thanks for the input Erickson and VDuece.

 

but what if the bypass flutenator or anti drain back twangulator valve malfunctions?

 

That is the way it is suppose to work, but consider it takes pressure to open that bypass and keep it open. According to some sources, the stock type oil filter will clog to the point of opening the bypass in fairly short order after being installed. After that the filter is doing little to clean the oil because the bypass is constantly open. Not only is this not cleaning oil, it is taking power to open the bypass. So, if your running oil through a filter that's clogged that is passing it through the bypass, the oil probably isn't moving at the same rate that it would through an open filter. Whether that would cause an engine to sump, I can't truly answer that question. It would seem to me that sumping has to do with the scavenging side of the oil pump not working as it should and that a clogged oil filter would decrease the amount of oil going into the motor and therefore make the scavenging side's function easier to accomplish.

Back in the mid eighties, I was at the Harley dealer in Lufkin, Tx. He got a call from a customer that was stuck on the side of the road. He asked me if I wanted to take a ride and I obliged. Long story short, the customer had used an automotive filter on his EVO motor (FXR) and it clogged. It either didn't have a bypass or it had one that wouldn't open with the pressure the EVO was pushing. It stalled his motor and it wouldn't run. Changed the filter, jump started the bike and he was on his way.

 

I already solved the sumping problem, I kept my twin cam