To confuse you even more it also depends on the media. A glass/synthetic media filter rated at 10-20 microns will flow as much if not more than a non-glass media (Harley) filter with a 30 micron rating.

 

I'm just gonna switch out to a K&N 170-C with the proper 30 micron rating and be done. I was given the Drag filter at the shop and like I said I didnt know there was a difference thats why I asked the forum for advice, I'm not trying to have people re engineer the motor or go agains HD specs.

 

There would be no way to know if the 10 micron filter was in the by pass mode so I stick with cHarley's way and use 90T filter for as long as I can get them.

 

You don't need to drain your oil tank. Just put some oil in the filter as specified in the FSM, put a little oil on the seal, and just replace the filters. Run the bike till warmed up and check your oil level and top off as required.

John

 

Exactly right on all counts: info and part numbers. Black EVO filter at dealership: $6.75.

 

Well, I'm not going to get into this same debate with you again.
If you had ever tested actual oil pressures or read up on the EVO oil system, you'd know that normal cruise speed pressures on an EVO motor only run in the 20 psi range and at idle they can be <5 psi.

Try THIS LINK on the S&S Cycle's website and click on "Should I run a 10 micron or 30 micron filter".

OR

Another LINK HERE.

.

 

I agree with you on those pressures, actually, and they're not far off from what I said.

Cruise is going to be in the 2,500 to 3,000 RPM range which, with a warm engine, should be in the mid to upper 20 PSI range based on the old rule of thumb I mentioned. If I were at 3,500 RPM and only seeing 20 PSI though, I'd be very worried about the engine and would want to check my big end bearings and journals immediately.

A <5 PSI oil pressure at idle would be indicative of a hot engine and probably marginally acceptable. Not the same as the cold start pressure I mentioned (and regardless of engine, on cold start with 20w50 oil you're going to be looking at the 50 PSI range until the oil heats up and thins out). On other vehicles running 20w50 (old air-cooled VWs and Porsches) they will spike at 5 bar + oil pressure on cold starts (1 bar = 14.5 psi, so 5 bar is around 70 PSI). At hot idle they drop to 0.5 to 1 bar.

Again, I would be very worried about an engine that only showed 20 PSI of oil pressure at 3,500 RPM.

The oil itself is not going to see a noticeable additional restriction from the filter, so unless there's a whole bunch of other gunk in your oil galleries that will fill up the 10 micron filter quickly there's not going to be a huge issue running a 10 micron filter for 3,000 to 5,000 miles.

As a practical concern, the difference between a 10 micron and a 30 micron filter just would not worry me. There's not going to be enough difference in actual restriction to matter much in the real world.

 

Soooooo..... bottom line is: buy the filter designed for your engine and THEN there are NO worries OR debates !!

Ride safe !!

 

This says it all. And many of you are wrong ... (from the link):

Should I run a 10 micron or a 30 micron oil filter?

A micron rating is given to show the efficiency of the oil filter (one micron is a millionth of a meter).

This leads consumers to believe that the 10 micron filter must be better for their bike. Here is where it can get confusing; though the 10 micron filter may have a higher filtration rating it does not allow the oil to return to the tank as fast. With this in mind, the 10 micron filter was developed for use with the Twin Cam style engine, which has a different oiling system that allows oil to be forced through a more restrictive oil filter. The reason for the tighter filtration was explained by the manufacture as necessary to assure all of the smaller passages, in the Twin Cam style engine, would stay clear of debris. If you run the 10 micron filter with an evolution style engine it will not be able to return oil through the filter fast enough causing the oil to back up into the lower end robbing power and/or causing oil to puke out of the lower end.

The 30 micron filter is designed to work best for your Evolution style engine, the filtration is still excellent and it will not cause oiling issues.

When it comes to filtering oil application is very important. There have been a lot of changes and updates too many filters on the market, with claims of better filtration, don't be fooled into using a filter that might not be the best for your bike.

 

This from the S&S website


Should I run a 10 micron or a 30 micron oil filter?
A micron rating is given to show the efficiency of the oil filter (one micron is a millionth of a meter).

This leads consumers to believe that the 10 micron filter must be better for their bike. Here is where it can get confusing; though the 10 micron filter may have a higher filtration rating it does not allow the oil to return to the tank as fast. With this in mind, the 10 micron filter was developed for use with the Twin Cam style engine, which has a different oiling system that allows oil to be forced through a more restrictive oil filter. The reason for the tighter filtration was explained by the manufacture as necessary to assure all of the smaller passages, in the Twin Cam style engine, would stay clear of debris. If you run the 10 micron filter with an evolution style engine it will not be able to return oil through the filter fast enough causing the oil to back up into the lower end robbing power and/or causing oil to puke out of the lower end.

The 30 micron filter is designed to work best for your Evolution style engine, the filtration is still excellent and it will not cause oiling issues.

When it comes to filtering oil application is very important. There have been a lot of changes and updates too many filters on the market, with claims of better filtration, don't be fooled into using a filter that might not be the best for your bike.