Educate Me on "Oil Starvation"

[AZViper08]

My understanding is that oil starvation normally occurs during high-g cornering. It's also my understanding that Gen I,II & III cars needed the comp pan installed to help prevent this from happening. My questions are:

1) Do the Gen IV's have something to help prevent this (I thought I read somewhere here that there is no dry-sump system on our cars)? I find it hard to believe the Gen IV's are vulnerable due to the performance the car produces and due to Dodge producing the ACR.

2) What is the difference (and benefits of each) between a "swing-arm" set-up, a dry-sump set-up or a baffled oil pan like the comp pan. I may have all this terminology messed-up, so feel free to correct me.

I posted this within the Gen IV sub-forum since I'm most interested in Gen IV responses. I currently own an '08, and if this should be posted elsewhere, I can definitely do so and apologize for any confusion. Any further explaination would be appreciated! Thanks.

 

[Paul Hawker]

Oil starvation is usually caused by cornering on a race track. It gets especially evident when owners change over to stickier tires than stock.

Earliest steps to prevent the oil in the pan from sloshing over to the outside corners and leaving the oil pickup dry was to baffle the pan. This slowed down the sloshing and was somewhat successful.

Later the comp coupes were equipped with swinging pickup arms, so when the oil sloshes over the pickup also swings over to keep in the oil.

08-09 cars come from the factory with swiveling pickups.

This is a further step in the right direction.

Racers sometime install accu-sumps which carry an extra amount of oil that can be released when needed.

Final step is to install a dry sump system which no only avoids oil starvation but also allows for additional capacity, but also allows the engine to be lowered in the chassis.

Dodge sells their standard SRT vehicles with high street and track performance levels, but for competitive track use the Comp Coupe is much better equipped for the rigors of racing.

 

[JonB]

Centrifugal / Inertial forces conspire to hold oil UP in the motor, or at the back, front, or sides of the pan. If you hold a bucket of water (or oil) and spin in a circle like a skater, you can extend the bucket all the way out to your side and NOT spill any liquid.

When cornering near or above 1G, These same laws of physics and fluid dynamics and viscosity keep some of the oil from reaching the oil pickup. Hard Braking and WOT launches have short-term effects. Trap too much oil so that it cannot lubricate, and even your starter can fail...........[when the connecting rod comes thru the block and hits it !]

Swinging arm pickups follow the sloshing oil, swung by lateral Gs. This helps. But they dont get the oil trapped above. This is why full crankcases of the CORRECT oil and filters are important. Gen 4 has done the most to prevent / minimize oil starvation. Time will tell.

 

[ShadowLight]

From what I've read on this it sounds like you can't hit the track in good conscience without upgrades to your car or you'll be wrecking it. But I can't imagine this is the case since the Viper made it three generations of track cars without everyone blowing their cars up. Can someone put this in perspective?

 

[AZViper08]

From what I've read on this it sounds like you can't hit the track in good conscience without upgrades to your car or you'll be wrecking it. But I can't imagine this is the case since the Viper made it three generations of track cars without everyone blowing their cars up. Can someone put this in perspective?

That's exactly my point. I've always wondered why a dry-sump system was used in the Z06/ZR-1 Vettes, but not in the Viper. I'm assuming dry-sump is more advanced and more expensive compared to a swing-arm set-up, so is it a cost-cutting measure used by Chrysler to skip dry-sump in favor of the swing-arm?

JonB and Paul Hawker, thanks for the awesome explainations! Even a non-mechanically inclined person as myself could understand.

 

[Paul Hawker]

Dry sump cost over 20X the cost of oil pan. You need additional pumps, wiring, and plumbing.

The extra 4-6 quarts of oil add weight, and expense.

For the most part, the swing arm system does the job at far less cost and complexity.

Dry sump keeps all the oil down low, utilizes gravity to function.

Fine system for +95% of all viper owners. The final < 5% can go to accusump or aftermarket dry sump.

 

[AZViper08]

Dry sump cost over 20X the cost of oil pan. You need additional pumps, wiring, and plumbing.

The extra 4-6 quarts of oil add weight, and expense.

For the most part, the swing arm system does the job at far less cost and complexity.

Dry sump keeps all the oil down low, utilizes gravity to function.

Fine system for +95% of all viper owners. The final < 5% can go to accusump or aftermarket dry sump.

Thank you, sir.

 

[Dan Cragin]

We club race several highly modified 08-09 Vipers without any oil delivery issues. The current changes to the G4 models work well.

Always keep your crankcase filled to the full mark and change to a proper viscosity track oil for hard use in high temperatures.

There are numerous minor changes you can make to your G4 Viper that will improve it for track use without sacrificing your warranty status or reliability.

 

[ROCKET62]

I thought the oil starvation issue was predominant on the '03/'04 and showed up on tracks with a long sweeping turn. I was also under the impression that for the '05 and '06 the cheap/quick fix by Dodge was a minor change made to the bearings which also showed up as lower overall oil pressure in the 05/06. I've also heard that some will add an extra quart of oil at the track as another "fix" for the oil starvation issue.

 

[Tom F&L GoR]

We club race several highly modified 08-09 Vipers without any oil delivery issues. The current changes to the G4 models work well.

Always keep your crankcase filled to the full mark and change to a proper viscosity track oil for hard use in high temperatures.

There are numerous minor changes you can make to your G4 Viper that will improve it for track use without sacrificing your warranty status or reliability.

This is a two-way issue. There is the urge to go to thicker oil when tracking but thicker oil will be slower to return to the pan... A safe operating practice would no high-G manuevers until the oil temperature (not coolant temperature) is up.

 

[repiv]

a swinging arm oil pan is only a partial solution. if your car exceeds an envelope of performance, the articulated arm of the oil pan will be sucking air at some point. Think of it this way, a viper oil pan is roughly 2.5-3x longer than it is wide. For the arm t swing 360 degrees it can only be as wide as the narrowest point (the width). Therefor, the arm won't be able to reach the entire length of the pan, regardless of where it is situated.

 

[Viper X]

Short answer is that the revised oiling system with the relocated swing arm oil pick up in the Gen IV cars has worked very well so far.

I've pulled sustained 1.35 Gs in my 09 ACR without any oiling issues ..... yet.

As for the Gen III cars, all of them would benefit from an oiling system upgrade like a swing arm pick up at a minimum.

With the Gen II cars, they need a trap door oil pan and an Accusump - my GTS ACR has both.

It would be nice if Daniel Lesser would comment on this. He's pretty knowledgable and has developed a revised oiling system for Gen III.

Dan

 

[JonB]

One other 'dry sump' benefit is that it eliminates the low-slung protruding pan. This allows the motor block to sit lower, and a V10 motor is heavy. The resulting lower C.G. is a definite benefit to handling and balance.

 

[Tom F&L GoR]

Let's keep going...

It's usually worth many 10's of horsepower (I know of up to 40) because it reduced windage losses, it applied a vacuum to the crankcase for better ring sealing, and rather than spilling a lot of the oil via the relief valve, was sized properly. It's a worthwhile thing all around. Might have to scale back expectations in a lower RPM engine like the Viper (but then again, it has 25% more moving crankshaft stuff flying around, so maybe.)

 

[repiv]

Let's keep going...

It's usually worth many 10's of horsepower (I know of up to 40) because it reduced windage losses, it applied a vacuum to the crankcase for better ring sealing, and rather than spilling a lot of the oil via the relief valve, was sized properly. It's a worthwhile thing all around. Might have to scale back expectations in a lower RPM engine like the Viper (but then again, it has 25% more moving crankshaft stuff flying around, so maybe.)

I've gone from the '08 swingarm pan to a dry sump. I can't say there there was a notable power increase from the transition. Granted, there were a number of other things changed at the same time on the car. It has been demostrated that a dry sump can increase HP, I just haven't seen it.

 

[SoCal Rebell]

From experience, I have seen 2 '97 GTS's put a hole in their block on a road course because of oil starvation. The '97s only had 7 quart pans and both cars were stock (including tires). I've run literally scores of track events in my '00 and with a 10 quart stock oilpan had no issues. When I got faster and put Hoosiers on I installed and new "windage" tray with trap doors and it worked great on a very fast, very high G track.

I never ran a Gen 3 but I remember the '03s had problems. I did do 4 track days in an '08 ACR with absolutely no problems.

 

[Paul Hawker]

One more issue to be addressed.

About 5 years ago Dodge changed their oil filter to a new model that allowed extra flow in high flow conditions through the bypass.

This oil did not go through the filter, but increased flow by allowing more oil through the bypass.

This would put more oil in the pan to reduce starvation also.

 

[Tom F&L GoR]

About 5 years ago Dodge changed their oil filter to a new model that allowed extra flow in high flow conditions through the bypass.

This oil did not go through the filter, but increased flow by allowing more oil through the bypass.

This would put more oil in the pan to reduce starvation also.

Yeah, but....

the oil has to be sucked up the pickup tube first to even get to (or bypass) the filter. Usually the filter goes into bypass when the oil is cold and pressure is high. I'd like a less restrictive filter element so the flow is high through the filter. Any more info on this?

 

[Tom F&L GoR]

I've gone from the '08 swingarm pan to a dry sump. I can't say there there was a notable power increase from the transition. Granted, there were a number of other things changed at the same time on the car. It has been demostrated that a dry sump can increase HP, I just haven't seen it.

Not surprised in a 6000 RPM engine, but in a 16,000 RPM engine it shows up.

 

[repiv]

Not surprised in a 6000 RPM engine, but in a 16,000 RPM engine it shows up.

I agree, although my engine spins to 7K.

On the oil filter, the pure power oil filters are the one's kevin s. from EE recommends.

 

[TexasPettey]

The cheapest answer is to run a bit over. I run about 1/2 to 1 quart over full at the track for my DE events. You always lose oil to blow off, etc. while driving. So, that keeps you at or above full during the entire session.

I know a number of C5 Vette folks that run 1 quart over if they don't have special pans, etc.

 

[Tabs1]

There is a difference between the Z06 dry sump and a true race dry sump. There have also been oil starvation with that stock set up.

 

[repiv]

There is a difference between the Z06 dry sump and a true race dry sump. There have also been oil starvation with that stock set up.

What is the difference? It's my understanding the starvation was related to the oil tank.

What is a "true race" dry sump vs. any other. In my research before going dry sump, I didn't find any dry sump marketed or positioned as "race" or "other" dry sump.

 

[Viper Specialty]

What is the difference? It's my understanding the starvation was related to the oil tank.

What is a "true race" dry sump vs. any other. In my research before going dry sump, I didn't find any dry sump marketed or positioned as "race" or "other" dry sump.

The ZO6 is a "dry sump" in that it has a separate tank, a scavenge pump and a pressure pump... but it only has ONE scavenge pump, and does not draw much vacuum. Its downside is that it is not that great at pulling oil out of the crank case and putting it into the oil tank.

A true "race" dry-sump will have 3-7 scavenge pump sections and one pressure pump section, capable of evacuating the crank case many times over. This ensures the oil is always kept in the tank, and the crank case does not still contain a large amount of oil. Often these pumps will be used to scavenge different parts of the crank case, not just the bottom, preventing oil from collecting just about anywhere.

 

[Tom F&L GoR]

So can you "overfill" a ZO6 (almost) dry sump tank so that the pressure pump never runs dry?

 

[Viper Specialty]

So can you "overfill" a ZO6 (almost) dry sump tank so that the pressure pump never runs dry?

I would say, not much.. if any. A dry sump tank cannot be filled to the brim as it also needs to separate out as much froth from the oil as possible before it is again pumped by the pressure section, and this requires "extra" typically unused volume. Knowing that, adding excessive oil to the system may help to keep oil in the tank a all times, but when the scavenge pump HAS cleared out the crank case effectively, it may overfill and overflow the tank.

 

[repiv]

The ZO6 is a "dry sump" in that it has a separate tank, a scavenge pump and a pressure pump... but it only has ONE scavenge pump, and does not draw much vacuum. Its downside is that it is not that great at pulling oil out of the crank case and putting it into the oil tank.

A true "race" dry-sump will have 3-7 scavenge pump sections, and one pressure pump section, capable of evacuating the crank case many times over. This ensures the oil is always kept in the tank, and the crank case does not still contain a large amount of oil. Often these pumps will be used to scavenge different parts of the cank case, not just the bottom, preventing oil from collecting just about anywhere.

Isn't a dry sump by definition and oil system that has a separate tank, hence the "dry" part of the sump (the pan has no oil storage capacity)?

As far as the stages go, the roots style pumps are modular, so you can add a stage, either scavenge or pressure. For instance, on my Dailey pan we added a scavenge section specifically for the turbos. It may be the way you worded your explanation, but you say a "pressure pump, capable of evacuating the crank case". The scavenge pumps are the part of the pump that evacuate the crank, or whatever portion of the engine they are plumbed to.

If indeed the Z06 only has one scavenge section i would view that as engineering fault rather than "race" vs I guess street.

 

[Tabs1]

thanks for the replies, I logged off before I saw the question. The newer Z and ZR1 cars have a larger capacity oil tank, and another help is to replace the pan with one from the aftermarket. A true race setup was described above.

 

[Viper Specialty]

Isn't a dry sump by definition and oil system that has a separate tank, hence the "dry" part of the sump (the pan has no oil storage capacity)?

Correct, but if a system does not have the ability to adequately keep the Crank Case "dry" on the race track, where on the street it is just fine- its not a true "race" derived system, it is a lower quality system begging to use the name "Dry Sump" as a selling point. As pointed out above, their fix was a larger oil tank, but in reality, all that did was allow more oil to remain i the crank case, and have an extra safety margin of pumpable oil- it still doesnt address the true issue, and it is still not in the same league as a multi-stage setup.

As far as the stages go, the roots style pumps are modular, so you can add a stage, either scavenge or pressure. For instance, on my Dailey pan we added a scavenge section specifically for the turbos. It may be the way you worded your explanation, but you say a "pressure pump, capable of evacuating the crank case". The scavenge pumps are the part of the pump that evacuate the crank, or whatever portion of the engine they are plumbed to.

It was just the way the explanation was worded, the last part of the sentence was to be applied to the "3-7 Scavenge sections". The first comma should not have been there. Just curious, as I havent talked to Dailey in a while- Do their Gen-3/4 systems still require you do remove your A/C system? Or have they engineered around that finally?

If indeed the Z06 only has one scavenge section i would view that as engineering fault rather than "race" vs I guess street.

Now you are definitely splitting hairs, lol. Nobody is going to market a dry sump as a true race car dry sump setup or a half-assed street car version. They are ALL technically dry sumps, but their specifications are what is going to determine how good they are. The cheaper versions are just trying to sell based on their names, not the configuration. Kind of like CP Pistons making a Street and Race version piston- they may both be pistons by the same manufacturer, however they are spec'd entirely different... but you better believe anyone selling a set is going to be touting the fact that they are CP Pistons, regardless of anything else!

 

[repiv]

The DE setup still requires ac removal on gen 3/4. The only dry sump system for a viper gen 3/4 I have seen/heard of is the one mitech does. It looks like the stack the pumps sort of partially inset & above the pan, thus making the dry sump pan about 1/4" deeper than the stock pan.

As far of the rest of the stuff, I think we generally agree, just differing points of view on how we get to the same conclusion.

you still want my '08 pan, I have it now.