Dry sump oil control, a thread.

[ericjon262]

I haven't done much yet, but I plan to deposit my dry sump research here as I look into dry sumping a 60V6.

Problems needing addressed:
-new oil pump mount
-old oil pump
-oil reservoir
-lines
-oil pan
-engine oil supply
-oil pump drive?
-turbo drain?

Some thoughts

how many stages? can you have too many? do the pumps need oiling? immediate thought is one stage per cylinder pair, and maybe one for the valley if the cam tunnel if flooded.

should top end oil drains be blocked or restricted and a scavenge stage be used for just to top end?

how do we get oil in? from the filter boss? do I need an external filter?

will filling in voids in the crankcase improve performance via crankcase vacuum?

does bay to bay separation improve performance?

[Jalisurr]

Will be interesting to see what you come up with.

I'd start by looking at the Corvette designs as they've gone through the evolution of their dry sump system since the introduction in 06. They went from a single stage system in the C6 Z06 and ZR1 (basically a normal oil pan with a pump at the bottom), to I believe a 2 stage in the C7, 3 stage in the base C8, and now the new flat plane LT6 in the C8 Z06 has a 7 stage system with six scavenging pumps, four of those being for the four sealed cylinder bays, one for the front cover and one head-drain scavenging pump

Seems like basically the more you can seal off the various engine holes and use a separate stage for each, the better. But then packaging becomes your issue

[The Dark Side of Will]

I haven't done much yet, but I plan to deposit my dry sump research here as I look into dry sumping a 60V6.

Problems needing addressed:
-new oil pump mount
-old oil pump
-oil reservoir
-lines
-oil pan
-engine oil supply
-oil pump drive?
-turbo drain?

Some thoughts

how many stages? can you have too many? do the pumps need oiling? immediate thought is one stage per cylinder pair, and maybe one for the valley if the cam tunnel if flooded.

should top end oil drains be blocked or restricted and a scavenge stage be used for just to top end?

how do we get oil in? from the filter boss? do I need an external filter?

will filling in voids in the crankcase improve performance via crankcase vacuum?

does bay to bay separation improve performance?

Will be interesting to see what you come up with.

I'd start by looking at the Corvette designs as they've gone through the evolution of their dry sump system since the introduction in 06. They went from a single stage system in the C6 Z06 and ZR1 (basically a normal oil pan with a pump at the bottom), to I believe a 2 stage in the C7, 3 stage in the base C8, and now the new flat plane LT6 in the C8 Z06 has a 7 stage system with six scavenging pumps, four of those being for the four sealed cylinder bays, one for the front cover and one head-drain scavenging pump

Seems like basically the more you can seal off the various engine holes and use a separate stage for each, the better. But then packaging becomes your issue

Thee are several things going on, that sort of happen in stages.
1. Basic oil control
2. Windage reduction
3. BMEP increase

1. The C6 Z06 dry sump addresses #1... And does a decent job of it. It doesn't really have problems unless the car has slicks and pulls >1.4gs in a left turn for more than 4 seconds. That means the "surface" of the oil is at 54 degrees from horizontal. Maybe a taller narrower external oil tank could help that?

However, that setup can still leave a "moist" sump with crank case pressure at/near ambient and liquid oil inside the engine which can contribute to windage losses at high RPM.

2. So going to greater capacity in the scavenge stages allows the system to keep less and less oil in the engine, leading to increases in high RPM power from reduction of windage losses

3. At the ultra-high end of dry sump systems, the running scavenge pumps have enough capacity (and the crank case is well sealed) to pull crank case internal pressure several psi below ambient pressure. This means that the pressure on the bottom side of the pistons drops by that amount... which increases full-cycle BMEP, and thus engine torque output at all RPM, by that amount. This can be a significant improvement in efficiency (BSFC) at light loads, as well as improving horsepower and engine output overall. Lower pressure also means less air density for entraining oil droplets to create windage losses.

I think that's what's driving the move from one scavenge stage to seven on the Corvette. Remember that the Ferrari Dino V8's (308, 328, 348, 355, 360) only have two scavenge stages, and they're both in the sump.

//

Obvi the most economical way of converting to a dry sump adds the least hardware.
Also, I'm sketch about anything driven on public roads that has the oil pressure pump driven by an external belt that can be damaged by road debris and requires frequent inspection.

With that said, maybe figuring out a way to supply oil from the external tank to the OE oil pump would be fine for the pressure side. That way only the scavenge pumps need to be added. If you're only after oil control, you don't need to get very fancy with it, and should probably put more effort into packaging a tall narrow external tank somewhere in your engine compartment.

[Jalisurr]

1. The C6 Z06 dry sump addresses #1... And does a decent job of it. It doesn't really have problems unless the car has slicks and pulls >1.4gs in a left turn for more than 4 seconds. That means the "surface" of the oil is at 54 degrees from horizontal. Maybe a taller narrower external oil tank could help that?

The C6 Z06 tank was already pretty tall and narrow, I think the limitation on high-g cornering was on the engine side. My understanding was that the issue in long left hand corners was that the system effectively 'ran out' of oil because enough was held up in the engine by the g-load and not falling down to the pickup. The C6 ZR1 and the later Z06s band-aided it and added a little chunk of extra capacity in what was effectively an add-on tank which increased the oil capacity enough (10.4L total!) that nobody found the limit. It may very well have been that on a really long left it would still be a problem, but the extra capacity was enough to get everyone through the longest left turn on whatever their local track was.

tank3.JPG (1.49 MiB) Viewed 1231 times

Side note, when your LS7 with fancy titanium rods spins a bearing, having a dry sump system (and oil cooler) means that many more lines and components that need to be replaced due to all the titanium shards distributed throughout them...

[Series8217]

There is at least one dry sump system that uses the stock internal OEM oil pump for the pressure stage, and an external pump that only has scavenge stages. JUBU makes it for the the Evora: https://www.jubu-performance.com/en/sho ... e_evo-2139

Papadakis posted a nice video of one of the dry sump systems they use on a drift car. I like the pan with the modular pickup assembly and the screened fittings: https://youtu.be/Ze-quG0nSqA?si=eVB_GkGjmp-QHnG1

[ericjon262]

I feel like creating a reliable pass through for the pressure stage into the pan could be problematic, please correct me if I am wrong. It would not however, be difficult to create a guard to go around the belt and protect it from FOD, and careful design could easily provide an easily removable inspection cover.

FWIW, inline 6 Duramax diesels have a belt driven oil pump, and it requires the cab to come off to inspect/replace.

because I'm dumb and waste my time dreaming about a NASCAR engine for my Firebird, I happen to have a legit NASCAR oil pan that I can look at, and also know that there are several examples on eBay right now, attached are a few pictures of the scavenge stage pickups in NASCAR pans. Each pan has a very different suction design, I would be very interested to see what the design considerations were for each pickup.

Note, oil pan 1, and oil pan 2 show pans that are designed to have each pair of cylinders separated from one another, oil pan 3 may or may not, it's hard to tell for sure. Oil pan 1 also has small holes in the dividers connecting the banks, I'm unsure of why.

[The Dark Side of Will]

1. The C6 Z06 dry sump addresses #1... And does a decent job of it. It doesn't really have problems unless the car has slicks and pulls >1.4gs in a left turn for more than 4 seconds. That means the "surface" of the oil is at 54 degrees from horizontal. Maybe a taller narrower external oil tank could help that?

The C6 Z06 tank was already pretty tall and narrow, I think the limitation on high-g cornering was on the engine side. My understanding was that the issue in long left hand corners was that the system effectively 'ran out' of oil because enough was held up in the engine by the g-load and not falling down to the pickup. The C6 ZR1 and the later Z06s band-aided it and added a little chunk of extra capacity in what was effectively an add-on tank which increased the oil capacity enough (10.4L total!) that nobody found the limit. It may very well have been that on a really long left it would still be a problem, but the extra capacity was enough to get everyone through the longest left turn on whatever their local track was.

tank3.JPG

Side note, when your LS7 with fancy titanium rods spins a bearing, having a dry sump system (and oil cooler) means that many more lines and components that need to be replaced due to all the titanium shards distributed throughout them...

Maybe they needed to borrow the Viper team's flippy-floppy oil pickup?

Don't air cooled 911's have 12 liter oil changes?

[FieroWanaBe1]

One of the SD4 dry sump pans I have, two pickups in the pan, head drains to pan kickout.
Windage tray is a mesh panel that I don't have. The pump is for a power steering rack, not engine oil.
The kickout would be on the correct side for oil to sling off into
viewtopic.php?p=162384#p162384

The second SD4 pan I have also has 2 pickups. Head drains to pan. Kickout is on the other side of the block. (LH vs RH), there is a built (welded) in crank scraper to clear the rods and crank throughs in the pan. It is pretty patched up and damaged.
viewtopic.php?p=162502#p162502

Something to be pondered about the kickout and the ability to shed oil and windage away from crankshaft, like a centrifuge.

Here are my parts from a C6 Grand Sport LS3 Swapped RX7.
viewtopic.php?p=163758#p163758
GM determined, to their detriment, that the 2-stage pump didn't need to have the standard baffles of the LS3. Aeration is also a problem. Later tanks had improved on this, but the pressure pump had issues with aeration, which extra capacity also improved. See the similar footprint design from ARE tanks, and deairation inserts for GMs tank. The corvette LT engine incorporate the oil tank into the engine package. The LS9 pump had increased pressure capacity too, the LS9 saw added piston cooling jets to the system, requiring more flow. Ported pumps offer something like 20% greater scavenge.
ARE offers an additional scavenge pump to replace the AC compressor to upgrade to oil system.
Many engine builders have used scavenge pump with factory pumps in V8s to add power with crankcase vacuum.

[ericjon262]

Thanks for the pictures! I've been going back and forth on this in my head a bunch, I think I won't be doing dry sump until I make the step to an LZ9, but I'll post up details as I come up with problems, and solutions.

[The Dark Side of Will]

They went from a single stage system in the C6 Z06 and ZR1 (basically a normal oil pan with a pump at the bottom), to I believe a 2 stage in the C7, 3 stage in the base C8, and now the new flat plane LT6 in the C8 Z06 has a 7 stage system with six scavenging pumps, four of those being for the four sealed cylinder bays, one for the front cover and one head-drain scavenging pump

Seems like basically the more you can seal off the various engine holes and use a separate stage for each, the better. But then packaging becomes your issue

It is amusing that in a wet sump engine, bay-to-bay breathing is desirable and can show significant improvements on the dyno, while the opposite is in play for a dry-sump.

Also don't forget that the E39 M5 took the moving pickup to another level... The S62 basically has a three sump pan (left, center, right), with solenoid valves controlling which section the pressure pump is pulling from based on g forces reported over the bus by the stability control system.