OK to have filter on outlet of scavenge pump in dry sump?

[JakeL]

All -

Since a lot of you F1000'ers out there are running dry sumps, I wanted to get some additional experience.

Installed a dry-sump in my Stohr, one of BRD's pans that I had good experience with on the DSR. I ran for a test day out at High Plains, and had no issues.

We came to Sonoma, and I found that in 3-4-5 laps, I would get lots of oil coming out of the overflow, and make a huge mess. Couldn't figure it out.

Now back home, we've looked at the lines, the pan, etc, and there are no obvious things at which to point a finger, EXCEPT, I have a Peterson 100um filter on the line which flows from the scavenge pump to the oil cooler. I am beginning to think that the filter is causing too much scavenge resistance, and the result was a slowly filling engine, ultimately resulting in high oil temps, power loss, and a huge mess.

As to why I had no issues at High Plains, all I can think of is that I didn't run enough laps in sequence to expose the issue, and/or HPR does not have the continued long/high-G corners like Sonoma does.

Soooooo, I wanted to check - are any of ya'll out there running a filter on the scavenge outlet? If so, what filter? Or, is that a big no-no, and I need to lose the filter on the scavenge outlet? Coop and I discussed it briefly, and he'd been told that filters on the scavenge line are a no-no. I thought I spied (a small ) one on JRO's citation, so I thought I'd get the lowdown from the community at large.

Thanks all,

-Jake

[formulasuper]

Jake, is your scavenge outlet filter to prevent debris from an engine failure getting into your oil cooler. If so I'd think a larger screen would suffice with out much restriction.

[JakeL]

Scott -

That's exactly the purpose. I had the Peterson filter from when I had the car in wet sump configuration, so I reused it, thinking it'd be OK. Beginning to doubt that.

-J

[Mike Devins]

All -

We came to Sonoma, and I found that in 3-4-5 laps, I would get lots of oil coming out of the overflow, and make a huge mess. Couldn't figure it out.

Jake, was the oil coming out of breather on the back of the motor or the overflow on the dry sump tank?

[Brett Lane]

Jake,

If you look at oil from an engine that is "making metal", the material can be so fine, I don't know how you can catch it all without a really fine filter. You are also restricting flow through the cooler.

I think the best thing is to ditch the filter entirely, and carry a spare.

Just my opinion....

[S Lathrop]

The content of the scavenge oil is mostly air.

I have used a finger screen (Earls) primarily to help separate the air and oil and trap the big metal parts before going to the cooler or oil tank. The oil cooler functions better when it is cooling oil and not foam. Also you want the scavenge pumps to pull a vacuum in the crank case.

I question how well a fine filter will separate air and oil before the cooler and the tank. And I can see that the filter will restrict oil flow to the cooler and tank thus the crank case may be positive pressure.

[JakeL]

Thanks for the answers thus far all.

Mike: The oil was coming from the overflow on top of the motor. The tank is not vented on its own, but it has a large vent line coming from the oil fill port on the engine.

I'll lose the filter and report.

-Jake

[glenn cooper]

At WGI I kept blowing the vent line off of the trans breather, even though the dry sump tank was "vented" to the clutch cover/oil fill.

I did run my GSXR like that no problem, but on the Kawi it was making a mess, so I took the other bung at the top of the RFR drysump tank and took the plug off of it and ran a line to the puke tank. No more trans breather line coming off (and nothing appreciable going to the puke tank), which may have just not been secured properly - V 1.0 had the line held on w/ the stock clamp, V2.0 had the line held on w/ a hose clamp which could not be made to sit flush due to clearance issues w/ the raised crankcase boss area that is the trans case breather box.