Mantis Deep Sump install

[steved0x]

Originally Posted by Gelbster

The kit I linked above does not have this issue.
It does have other issues but they are easier to deal with as noted elsewhere.

Yeah, those are the same style of oil return tubes I used too.

Cutting the hole to fit closely probably won't compromise the effectiveness of the windage try, you will just have slightly more gaps to work with the existing small holes in the mantis design.

[thstone]

Originally Posted by steved0x

I went with the 997 (987?) oil return tubes, whichever come with the LN kit.

I also used the 997 swirl pots that came with Pedro's TechnoSump kit. However, I did have to trim the windage tray to fit the EBS X-51 baffle.

997 oil return lines (not really swirl pots)


Before trimming


After trimming


Final result

[Gelbster]

1.The windage tray - aka horizontal baffle - to which side of the gold colored spacer do you fit it and why? I say on the upper face to create a deeper reservoir of oil to feed the pick-up.
Some instructions say to put it on the lower face.That reduces the reservoir by a huge amount.
2. Replace the extended sump bolts supplied with correct size s/s studs. Use blue Loctite in the crankcase holes,use green on the nuts(double nuts) that retain the sump plate. Reduces risk of stripping threads in future,easy to remove sump plate to inspect for debris.Do some careful measuring to choose the correct length and chase the threads in the crankcase.

[steved0x]

Originally Posted by Gelbster

1.The windage tray - aka horizontal baffle - to which side of the gold colored spacer do you fit it and why? I say on the upper face to create a deeper reservoir of oil to feed the pick-up.
Some instructions say to put it on the lower face.That reduces the reservoir by a huge amount.
2. Replace the extended sump bolts supplied with correct size s/s studs. Use blue Loctite in the crankcase holes,use green on the nuts(double nuts) that retain the sump plate. Reduces risk of stripping threads in future,easy to remove sump plate to inspect for debris.Do some careful measuring to choose the correct length and chase the threads in the crankcase.

Windage tray goes up top above the deep sump spacer. It was the old directions that had it go below.

The studs sound like a great idea. If I ever take mine off again I may go that route.

[Gelbster]

"Windage tray goes up top above the deep sump spacer. It was the old directions that had it go below"
The Instructions only changed after I had an on-line debate with the vendor - and he still disagreed & then redacted some of my explanation !
A Forum Member who had installed it according to the old instructions and wasn't too pleased when he PM'd me for the explanation.
The issue made me skeptical about products they developed. Very nice guy but....

[Dlirium]

Got the holes cut, now fits perfect. Finished up the install and dropped 11 qts of Mobil 1 15w50 in.

[steved0x]

Looks great!

[jaykay]

Originally Posted by Dlirium

I hadn't understood this post until I had to go in and face the same problem!!

Well there seems to be another camp that has updated oil return tubes discharging above the windage tray. From what I can see there is no choice if you are working with the updated 987 type....they look to sit high in the sump and don't look like they can extend down below the plane of the tray. In my mind this seems like what you don't want when you have a windage tray in place.

The older type reach down below the tray and dump oil in a restricted volume beside the oil pick up....filling from that point upwards. This is what you want when oil wants to climb the walls of the sump due to windage, Gs, slosh etc. You want a restricted segmented volume around the pickup staving off oil starvation....by trapping returned oil there

This is just my opinion looking at the arrangement visually. When I looked into this mod I was sure to stay with old swirls deaerating and putting oil directly under the tray right next to the pickup.

[jaykay]

Originally Posted by Gelbster

1.The windage tray - aka horizontal baffle - to which side of the gold colored spacer do you fit it and why? I say on the upper face to create a deeper reservoir of oil to feed the pick-up.
Some instructions say to put it on the lower face.That reduces the reservoir by a huge amount.
2. Replace the extended sump bolts supplied with correct size s/s studs. Use blue Loctite in the crankcase holes,use green on the nuts(double nuts) that retain the sump plate. Reduces risk of stripping threads in future,easy to remove sump plate to inspect for debris.Do some careful measuring to choose the correct length and chase the threads in the crankcase.

I like this installation of studs idea. Perhaps you could provide a little sketch so all can get it right and benefit from your setup. Did you bottom the studs in the case and just lock them with blue?

[Bebbetufs]

Like I said in another thread I disagree with this assertion. You want the oil at the bottom of the sump to be as free of air as possible. This means that the bottom is the last place the oil should get to to give it as much time to dump air as possible. You want to be filling from the top. Remember that there is a relatively large volume above the horizontal baffle. The baffle represents the original bottom of the pan, and there is quite a lot of oil in there before it even touches the dip stick.

The baffle is there to keep oil from sloshing away from the pickup (green) and to keep it from climbing up the wall. This means that every time the car corners oil will be gushing out the holes in the mantis baffle like small "underoil" geysirs (red arrows). The longer the turn the less efficient the baffle as the oil, especially when hot, will easily escape through these holes and likely through the flaps which never seal completely, (at least not the BMW rubber flaps I have been testing).

As you see from the figure the deciding factor is the height and efficiency of the horizontal baffle, but this requires the horizontal one to let as little oil escape as possible.

I would prefer one way flaps on the horizontal baffle as well to keep the oil in there (red arrows)

[steved0x]

I always wondered if the holes allow any foam that gets under there to bubble up instead of being trapped under there.

[Gelbster]

It is good that ppl are questioning the physics of the sump kits.
TuneRs kit has the 997 swirl/pickup tubes. Originally they had the horizontal baffle in the wrong location.I had quite a debate with the manufacturer on this issue.Eventually they changed their Instructions and heavily redacted the on-line debate - which I am totally O.K. about.The objective was to fix what I claimed was a mistake and they did.
The oil-foaming is an important issue (imho)but seldom mentioned nor discussed except by a few. Not surprisingly, Jake has shared some useful insights on this issue.
One response is to use a specifically low-foam oil. Yes, it is available because some other high volume production engines have a oil-foaming problem.

[Bebbetufs]

While I'm new to the flat six and it's problems I've spent a lot of time thinking about the oiling problems with the 928/ 944 platform. In that camp more and more people seem to understand that aeration is an major factor. Some run Valvoline racing oil because of it's anti foaming properties, but there is no conclusive data that this is enough.

The 928 engine has problems with oil collecting in the cylinder heads. Enough oil is trapped there to possibly uncover the pickup, at least momentarily. This has been conclusively proven using modified valve covers with plexiglass windows, cameras and strobe lights. The same problem is occurring with the m96 where oil pools in the front of one bank during breaking and in the rear of the other during acceleration. I believe this is why some think it is important to remove resistance to the oil returns to the sump. However, the oil is pumped back by the scavenge pumps, so the swirl pots should not really slow down the return.

I believe a major part of the problem, and one which Porsche knew about and addressed with the dual stage scavenge pumps, is the oil pooling in the head when it is desperately needed in the sump. Then, when the car changes state a big volume of highly aereated oil is returned by the scavenging pump. This is dumped into a small volume of oil in the sump and this leaves little to no time for the entrapped air to escape before the oil is sucked up by the pickup and delivered to the bearings. Usually during heavy acceleration when a high pressure oil film is needed the most.

Keep in mind that I have no way of proving this, it is only my current theory. What actually goes on i a dynamic situation is anybody's guess, but shock waves may form, and the oil will be splashing around a lot. The volume of oil moved by the pump is staggering.

[Bebbetufs]

Originally Posted by Gelbster

It is good that ppl are questioning the physics of the sump kits.
TuneRs kit has the 997 swirl/pickup tubes. Originally they had the horizontal baffle in the wrong location.I had quite a debate with the manufacturer on this issue.Eventually they changed their Instructions and heavily redacted the on-line debate - which I am totally O.K. about.The objective was to fix what I claimed was a mistake and they did..

While I agree the horizontal baffle should be on top if you look at my sketch you will see that it does not really matter as long as the vertical baffle fits closely. This is because the end of the baffle plate is too far from the pickup to make a difference that I can see.