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YOUR RESEARCHModifying oil retrun lines/swirl pots
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Run factory type canister filters mahle/mann/k&n ps-7011
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I run the factory type canister filters Mahle/Mann/K&N PS-7011 with by-pass disabled .
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I am running on Hoosier R7's and not seeing a drop with the LNE kit.
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The theory is that the scavenge pumps deliver oil that is too aerated to be used immediately by the main oil pump.
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Suggestion
Or compared to XP9 which is what most of us are using on the track as recommended by LNE.
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Suggestion
I understand early on 997 owners were replacing their return tubes to swirl pots but more recently people realize the update in 997 is better as it return oil back to the pan faster.
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First I had the X51 baffle which helped but did not solve the pressure drop.
Even with the Motorsport oil pan I see sometimes considerable oil pressure drops on high speed corniring with higher rpms
I need some expert feedback on an idea I am having.on modifying the swirl pots in order to possibly improve the oil supply to the pick up tube
Considering the following
1. the pick up tube is located centrally in the oil pan
2. this central zone is defined by some rectangular 'bucket' created by the oil baffles
3. the baffles have windows with flaps to keep the oil centrally during cornering,
4. during cornering the flaps also prevent the oil to go in to the central zone as on one side they are closed, by the oil moving against them
5. and on the other side of the central zone most of the oil will run along the baffles to the other side of the pan and not into the central zone
6. the oultets of the swirl pots direct the oil outside the central zone, so during cornering almost none of this oil is reaching the pick up tube
What is the purpose of the swirl pots jetting the oil
outside
of the baffled zone?
Were they afraid that the oil stream coming out the swirl pots under high rpms could interfere with the oil pick up stream?
What about modifying the swirl pots such that they deliver the oil substantially more in the central zone of the oil pan.
I think this could solve already a lot of the oil starvation issues (at spirited street driving). With higher rpms the oil flow rate goes up proportional. The baffled zone in the oil pan gets depleted of oil faster faster. The swirl pots resend the oil back into the pan, but outside the baffled central zone. So it takes more time for the oil to return to the pick-up tube. or with serious cornering the oil will never arrive at the pick-up tube.
in 997, the swirl pots are simplified pretty much into return tubes. I understand early on 997 owners were replacing their return tubes to swirl pots but more recently people realize the update in 997 is better as it return oil back to the pan faster. Better to have aerated oil than no oil at all I guess.
As for the baffle, x51 style could be an upgrade as it retain the oil in the center pick up area better and the metal door instead of rubber flap reduces the chance of rubber deform or fall off over time.
I dont know if anyone modify the location of the returned oil.
I know about the 997 return pipes and 996 swirl pots. I have the X51 style oil pan and still I see with very moderate cornering (compared to track cornering) pressure dips on the dash meter. So I imagine the real pressure drops are significantly larger then on the meter. This was also confirmed by my indy who tested it on serveral cars. To rule out any car specific influences.
My specific point is that both the swirl pots and return pipes direct the oil OUTSIDE the central zone of the pick up tube. The outlets are directed to the sides of the oil pan rather then to the central zone. Why they don't deliver the oil there were it is wanted, namely centrally, especially when you have a X51 or similar oil pan which would benefit from this! I believe the oil retaining capacity of the X51 oil pan is very minimal especially with longer turn and high rpms.
I have been down this road. First I had the X51 baffle which helped but did not solve the pressure drop. Going to the LNE 2 quart deep sump with 997 return tubes solved my pressure drop issues on the track completely. If you look at the design on this deep sump it basically puts the oil pickup inside a box with baffles above it so it's nearly impossible for the oil to slosh out.
It appears the TRS kit is similar but does not include the EBS Racing X51 baffle? Perhaps that's the difference?
Also I wonder about 3.4 vs. 3.6 engine pressure drop? I have a 3.6 2003 C2. I am running on Hoosier R7's and not seeing a drop with the LNE kit.
I have the LN kit too with a 3.4 (new remanufactured from Porsche with upgraded IMS), and I am still getting drops running XP9. I had the FVD Brombacher pan before that and was also getting drops.
For me, the drops start happening 10-15 minutes into a session. The LN pan has made it so I don't have to pit early, but it is still dropping. Oddly, on my old motor (before I blew it up) I do not remember there every being a pressure issue. My car is a 99.
It may be the difference, but I put in the EBS baffle. Its absolutely mystifying because with the vertical and horizontal baffles, there should be no way the oil can run away from the sump.
That said, my car is a boxster with a 3.2 and supposedly they are worse about the pressure drop. At this point, if its gonna happen, its gonna happen. If it blows, I'll put in an Ls motor or something.
Consoles might be slightly different in design, but the pumps are all the same across all the models.
Someone mentioned above with the 2 Qt LN kit that there are no drops until 15 minutes into a session. That's concerning. This may be a temperature related issue or perhaps a faulty pressure relief or even pressure sender. Something is amiss in that situation.
The FVD pan other than being cool because it's billet doesn't help if you have tires stickier than a factory N spec tire.
Likewise, the factory X51 baffle too doesn't help without the added volume and the anti-slosh tray.
The baffle we make for the 2 quart deep sump is totally different than the EBS baffle, which we also sell with our .5 qt deep sumps since there was no reason to reinvent the wheel since EBS make one for that application before we did.
I have been studying this concern for some time now since I one of my 3 personal engines experience this pressure drop after 15 min of track time on stock tires.
The engine that experiences this has the least miles of the three(70k), but has had the toughest life, and I believe has a loser clearances than the others.
I definitely believe the temperature is related due to the temp increases the clearance and also thins the oil which both lead to more oil flow. So much more oil flow that it empties the sump of unaerated oil.
The 9.3 quarts or 11.3( with deep sump) should be plenty of oil, even with the high flowing if it can return in unaerated form fast enough.
The problem seems to be inability to return and/or unaerate fast enough.
I have even considered removing the scavenge pumps in the theory that they are producing too much aeration at high RPM more than they help with oil return. Also increasing the size of the oil drain holes in the case (under the IMS) to increase oil return.
Something must be done. Or you should design a low cost streetable Dry Sump set-up. (yes I have thought about that also).
But remains my initial question ... why the oil delivery is not done centrally, within the baffles?
With an X51 oil style pan, if the oil would be delivered centrally closer to the pick up tube the oil pumped back to the sump will get delivered inside the baffle so there will be more oil for a longer time.
Whereas in the current situation it is delivered outside the baffles and under these g-foces it will always stay outside with such g.forces, as a result the oil supply still gets depleted sooner or later
A test removing the swirl pots shows that oil pressure stays up in the long sweeping corners. However I suspect that on the longer runs it will be detrimental to foaming.
This is just my idea and obviously the expert that knows more about oil, internal pressure and the design of the oiling system can chime in.
The reason to return oil outside of the baffled area is to allow the oil to further get rid of aerated oil. It also keep the foam outside of the baffled area The returned oil drop from the top and the oil at the bottom are allowed into the pick up area from the low point. By returning oil directly into the center area, may create a lot more foam on the top and aerated oil push to the bottom and getting pick up by the pick up tube.
Just a thought.
Yes, that would be the main issue I think. Also consider that the oil return-flow also depends on rpm's so with higher rpms the oil will flow stronger into the sump, with more foam possibly to be formed in the existing oil puddle.
Think about the kitchen sink full of water with the water tap opened at maximum. But one could try to use the baffle as a screen to catch the oil stream and make it flow down into the central sump area thereby minimalising foaming.
Further the design of the LN deep sump kit is still somewhat flawed as the oil can still flow from one side of the sump to the other side without entering the pick-up zone. Yes there is a standing ridge in the middle of the OEM oil pan but it is not high enough. They should have provided an oil pan with a ridge reaching till the windage tray, physically dividing the sump in a left and right zone , with the baffled pickup area in the middle, and further a flow path which will force the oil into the central area.
I am really considering to put a deep-sump kit on my street car as I see too many oil pressure drops on the meter. Even with normal spirited street driving, x51 oil pan and 10w50 oil. I do not trust these motors anymore.
We have no plans to redesign the 2 quart deep sump or come out with a dry sump kit. The original design was verified on a Koni Challenge car and all the data collected and backed up with nearly a decade of data shows our design works when the proper oil is used and engine temperatures are managed properly.
Yes, I can agree with that. Maybe my wording �flawed� is not correct. If it works in practice why change a working design. See it in the context of brainstorming.
I do not have an oil temp gauge, so I do not know what that peak temp is, but my water temps would get high (sometimes just over the line between the 180 and max. Have not overheated though. The car did this with both the old motor and the new motor. I just installed the center radiator, so we will see if that helps.
I have your spin on adapter running the Napa Gold filter, and XP9.
Yes I do have an oil temp gauge, reading from the factory oil temp sender. Oil temp will approach 250F within 15 min of track time, then I will pit to cool off. Track is a small technical track with a lot of tight turns and only two straights that can reach 100mph at the end. I assume your Koni Challenge test car is running an efficient oil cooler? Track temps are usually around 100F. I run the factory type canister filters Mahle/Mann/K&N PS-7011 with by-pass disabled .
Some have had better luck running XP6 on the track when the oil temps are in excess of 240F.
With the spin on filter adapter, we recommend running our billet filter on track for optimized flow, especially if going with a thicker oil like XP6.
Stock oil cooler on the car I was referencing data from.
Like I mentioned on a previous post, you might want to consider XP6 instead and see if that helps with the pressure drops when the oil temps exceed 240F.
I think a lot of our issues with pressure drops on the m96 engines are due to foaming/aeration of the oil at high temps/flow.
I would love to see some data on oil foaming comparisons . ie oil A foams at 230F , oil B foams at 260F. Unfortunately none of the oil manufactures provide this data or comparisons. They just advertise anti-foaming agents in their additive packages.
I know the Power Stroke engines suffered a problem with the injectors that were oil operated under high pressure and foam would cause ineffective operation of the injectors. At the time an additive was available to solve the issue, but is no longer available, I assume the additive is now included in the specified oil..
Our engines having scavenge pumps operating at high speeds definitely contribute to oil foaming, and an oil with the highest resistance to foaming/aeration is a must to avoid pressure drops. I would love to know how much better XP6 is compared to M1 5w-50 in term of anti-foaming.
Driven's XP line of oils have the strongest anti-foaming packages on the market. Lake knows this is a big problem and they have done extensive testing to test for foaming control. There are tables that indicate what is the proper oil viscosity for a given bearing clearance as well as temperature. Although Driven XP oils hold their viscosity better than most every other oil on the market, just because an oil can handle the temp, that doesn't mean its ok the engine is running that hot.
Still no clear answer why the oil is not returned in the direct vicinity of the oil pick up inside the baffle.
Initial tests show that removing the swirl pots or return tubes results in a much more stable oil pressure under certain hard cornering.
the main problem is that under high rpm most of the oil goes to the heads and that is when oil levels get low under hard g combinations
The theory is that the scavenge pumps deliver oil that is too aerated to be used immediately by the main oil pump.
But, as I have always said in modifying engines for racing or high performance," when the results differ from the theory, believe the results, and invent a new theory".
So be very sure of your results, then rethink the explanations.
Porsche obviously realized the scavenge pump were causing too much aeration in the oil return hence the design of the early 996 AOS "swirl pots"., then with further testing realized the swirl pots were not effective in reducing aeration or maybe even in some instances/circumstances increasing aeration, hence the redesign with no "swirl" return tubes.
None of this is new.. Same challenges, same variables.
Oil temperature and engine temperature have always been the underlying issues... When oil is thinned out due to heat, and components that dictate oil pressure with their internal clearances have these clearances open up, due to heat, its a double negative.
This is why long sessions and back to back sessions often end with a wallet thinning exercise, especially in the heat of summer.
When you see a few hundred engines fail the same way, its pretty clear. Modifying the internals from clearance perspectives, and coupling oils that maintain viscosity at extremely high temperatures have alwways been the key.
Porsche used to offer tandem scavenge pumps for the heads so as to be able to scavenge oil from both sides of the cylinder head. They discontinued these pumps as they were part of the X51 package many years ago. Everyone of the forums clamored for them, and I made them, but no one bought them. We have a hand full left, but it has taken me many years to sell them and I'll never recoup the development costs.
The X51 3.4 (with dual scavenge pumps on bank 2) did not sell well for Porsche either. It was not available factory installed in the US, and kits were so rare I have never seen one in person, even working at the Porsche dealership.
Over a decade ago when I was looking for one, they were already discontinued, and finding one in the wild was almost impossible(and would cost a left nut)..
I only found out that you could supply them a year ago when browsing through your products ( Thank you for providing such hard core products). There has not been any reviews or feedback on this product, and rarely a mention of it except for extreme track or race conditions. Does your Koni Challenge test car have the dual scavenge pumps?.
Porsche does not include a dual scavenge pump in the 3.6 or 3.8 X51 kit. A lot of Porsche people insist that the oil pressure drops are not even a problem on street tires or on the street. But I know that it does.All 3 of my m96 engines are of the 5 chain design. Maybe the 3.4 (5 chain) makes more aeration then the 3.6 3.8 (3 chain) engines? the 3.6 3.8 ( 3 chain vario-plus) engines have an "internal" channel that scavenges from both ends of the heads, so an external dual scavenge pump isn't necessary on them?
The Koni Challenge car was campaigned by a customer, not something we built. He was having starvation problems with the available solutions at the time and he was the first to run our 2 quart kit, which solved his issue. He was running race oil too, so that helped. No scavenge pumps on that engine, or that I was aware of, since he had oil starvation problems previously.
On the 3-chain, oil pressure is also being used to control variable timing and lifter, versus just timing on the 5-chain engines, which contributes to oil pressure related issues. The vane cell cam timing adjusters are hell on oil. We know that for a fact.
It is in my experience that the 3 chains have more issues on track than the 5 chain engines, but then again, they are pushing more HP than the earlier engines.
I have seen a 3.6 X51 tandem scavenge pump - we modeled ours after that pump. There was also a 3.4 RoW X51 that also had a tandem scavenge pump. Porsche made one pump for each bank (they are side specific), but never fitted both to one single engine. As far as I am aware, our kit was the only one that let you install on both banks.
I ran out billet tandem pumps on my mixed use street/track cars for years until I had one of them lock up in cold start when it was -45 with the wind chill and the car had been outside and was through and through cold. They are very durable. That engine is currently being rebuilt and updated to test some new piston designs from JE.
I completely agree with that! If the turn is long enough (and on the street they can be as long as 270degrees you will eventually run out of oil supply at the oil pick-up. Maybe small dips but just enough to cause incremental damage or strain on the internals which rely heavily on fresh/cool oil sypply.
Don’t forget about the piston squirters.. They provide an internal oil leak while they deliver oil to cool the pistons. We’ve found that the way these fit into the carrier is a problem that can lead to just enough oil pressure and volume loss with hot oil, and a hot engine to help cause a problem..
There are ways around that, and we employ them in all Stage II and greater engines. Back to back these mods are good for 5-8 PSI at minimum, that can be the difference between life, and death for the engine. This is critical, as the oil for the squirters is taken from the main bearings directly.
So am I reading the comments above correctly that the X51 engine, such as fitted to the 40th AE 996, does NOT have the additional scavenge pump? I thought that was one of the big design features of the X51 upgrade.
The 40th Anniversary with X51 engine should have the single tandem scavenge pump from what I have seen in previous customer engines. However I am not sure if it was customer added or original to the engine.
