Will the c8 LT2 z51 be the only engine with dry sump oiling system?

[JB]

Dont ask me why but it dawned on me that the LT2 might not come standard with a dry sump oiling system.

i think it should but if not that would be a good reason to order up the z51 package...

is it really neccessary? Of course not...but never having owned a vehicle with a dry sump oiling system...its something I am interested for my next sports car...(especially if its rear mid engine)

all LT 2 s or just z51 packaged vehicles during the first year of production.?

what say you?

[Weasel]

Yes. That would be a great idea.

[Boomer]

Am I gonna need a catch can? Never did with my base C7.

[John]

The overwhelming majority, maybe 80% or even 90% or 95%, have owned very successfully their dry sump C7’s without a catch can.

[JB]

Ive never been a believer of catch cans over the years. Jmo

[meyerweb]

The issue "requiring" a catch can isn't limited to dry sump cars. The LT1 dry sump had an issue with overfill causing oil to get into the intake, but that's a different issue than catch cans are intended to solve. Catch cans deal with crankcase vapors coming through the positive crankcase ventilation (PCV) system. The PCV system allows crankcase vapors, including combustion blow by and oil vapor, to be sucked into the intake tract, and over the backs of the hot valves. In a carbureted or port injected engine, those vapors mix with the detergents in fuel, keeping them from adhering to the valves. In a Direct Injection engine, there's no fuel and no detergent washing the backs of the valves, and the oil in those vapors DOES adhere to the valves and build up deposits. That's a simple fact, not an opinion.

What you can argue about is how much build up there is, and how much it matters. On some VW engines, it has caused serious problems in less than 50K miles. Some BMWs have had serious problems, too. GM says there's no problem on the LT1 and LT4, but on the LT5 did mix Port and Direct injection. Perhaps keeping the valves clean was part of the reason?

Anyway, back on topic. Like I said, the issue with valve coking and catch cans has nothing to do with whether the engine is dry sump or not. I suspect ALL the C8s will have a dry sump, for one specific reason: it lets the manufacturer position the engine lower in the chassis, which lets GM lower the rear deck and improve rear vision. And, of course, lower the center of gravity. And it really doesn't cost that much more than a wet sump design to make

[Milliwatt Rob]

The two primary advantages of a dry sump system are, I believe,

1. a smaller oil pan under the engine, thereby allowing a lower mounted engine, and therefore a lower center of gravity, and

2. More positive oil pickup for the primary oil pump, therefore being more suitable in high G force situations.

I don't think, in the C7, it made any difference in engine mount height, wet sump vs dry sump, but I may be wrong. But the second point may hold more validity, especially in a track driven car.

[John]

The ZR1 introduced GM’s first dual-fuel-injection system, which employs primary direct injection and supplemental port injection. These will further mitigate some possible previous LT1/LT4 issues. GM will not go backwards with the LT2, but incorporate past learnings of the LT1-LT5 family, and additional new ones too — such as many of those enhancements they brought out on the 2.7L TT.

Not concerned, e..g, more motor progress will be revealed to us when the LT2 is.

[meyerweb]

I don't think, in the C7, it made any difference in engine mount height, wet sump vs dry sump, but I may be wrong.

Correct, but since the driveshaft and transmission location had to support the wet sump engine, the dry sump pretty much had to be mounted in the same place. And I think a rear mid-engine design, with no need for driveshaft clearance, probably makes lowering the engine easier.

[John]

Ive never been a believer of catch cans over the years. Jmo

I will never forget the comment of a GM Powertrain Engineer who was asked, how come you did not put a catch can on the C7. His response was, “if the car needed a $20 part, we would have put it on.”

[Boomer]

Definitely got the answer to my question in post 3 and then some. Thanks folks.

[Racer86]

Dry sump is necessary for 100% oil pressure control. One pump pulls the oil from the oil pan, and pumps it into a tall tank. The oil enters the tank at an angle to introduce a swirling pattern which helps remove any air that the pumped oil may have intrapped in it. At the bottom of this tank is a hose that allows the oil to enter the inlet of the second pump. This pump is the oil supply to the engine bearings. The tank is made as tall as possible to insure that a head of oil is available to the pressure pump during all Corning and its resultant G force. The sump pan can be much swallower as it does not hold the oil as a wet sump pan. This allows the engine to be mounted lower in the frame. A racing drysump contains 4 scavenging pumps and 1 pressure pump. Oil is scavenged from 3 points in the oil pan and 1point up in the vee of the engine.

[JB]

With the move to rear mid engine and the supposed ultra high cornering loads this design offers would it make sense to make dry sump oiling standard?

nothing worse than starving an engine of oil During new jigh load cornering capabilities...

i believe the shared v8 between ferraris 488 and the maserati gran sport..

the front engine maserati coupe is a wet sump while the ferrari 488 is standard as a dry sump...

i would hope the dry sump is standard...

interestingly enough i had been watching a build and race on a (996) 911 that grenaded its engine because of oil starvation on a track day....so the guy put in a ls2 v8 from a corvette or camaro...

meanwhile rhe v8 is tirned around as its installed in the porsche 996 911 and lo amd behold again...the engine was starved of oil on the race track due to cornering loads and grenaded the v8...(i think the reversed position of engine caused the oil starvation)

i have a wet oiling system on my present corvette as have my previous corvettes and it was never an issue...

i think my current corvette pulls 1.0 lateral G’s and it was never an issue..that said supposedly the c8 will pull harder, corner even better so maybe having a dry sump standard makes sense?

making it stamdard would allow for all versions to position the engine slightly lower for a lower center of gravity for better handling

just shooting the breeze

[Racer86]

High sustained G loading will cause a drop of oil pressure in a wet sump engine. Even high g loading throught a chicane will cause a drop of oil pressure. It’s a fact. Dry sump is the correct solution. Just touching 1 g for an instant is not hard cornering. With all due respect , most track day cars are not driven at a competitive racing speeds. Yes I know about accusump systems and trick oil pans with trap doors and baffles, but the solution is a true dry sump system. Maybe a dry sump system is not needed on a street car or even some track day cars, but that does not mean that a dry sump system is not necessary when driving at timed competitive racing events. It is. Proven fact. Your opinion may differ,

[Mobius]

The overwhelming majority, maybe 80% or even 90% or 95%, have owned very successfully their dry sump C7’s without a catch can.

Still, I think we should start a thread on "The C8 and oil ingestion issues with Direct Injection", and watch it rapidly grow to 40+ pages of debate - just kidding!

It makes sense to me that the C8 should only come with a dry sump for the LT2, especially if the incremental cost of going from wet sump to dry sump is minimal.