Stock vs. Accusump vs. Dry Sump

[SASQUATCHelvis]

I've been reading a lot of comments about LS3s grenading due to oil related issues on track. I'm not running slicks or anything, but I'm trying to do 3-5 track days a year for the lifetime of my car and I'd rather not have to replace my engine anytime soon, or ever for that matter.

All that said, what are the advantages and disadvantages of a accusump and a dry sump, or am I ok on the stock motor until I start pushing more power and making more grip?

[Firefighter]

Subscribing for the conversation.

There is also the option of the Improved racing baffled insert with their crank scraper. I think this is a good option also and it's only a few hundred in parts. The install might be a pain though since the pan has to come off for the mod.

Sent from my SM-G900V using Tapatalk

[X25]

Oil starvation has been a major issue since LS7 and LS3 were introduced to LS engine family. Unlike LS6, which seems to be much more prone to the issue, both LS7 and LS3 (whose head design is actually based on lessons learned from LS7) suffer from oil starvation, especially during long left-hander turns where the oil might be trapped inside the heads, and oil starvation issue might occur.

To overcome the issue, LS7 comes with a dry sump. A real dry sump system would create negative crank pressures, and feature multiple scavenging locations, but GM's system is somewhat a hybrid system, and does not provide those benefits. Still, it works, and does the oiling job well. However, it was later found that the capacity (~8.5 quarts?) is still not enough to provide oil during long left-handers; the system was simply running out of oil in the container. LG Motorsports came up with an extension kit that extends the oil capacity by a few more quarts with the additional container bridged to the original container hidden in the fender, and this was also later adopted by GM itself beginning from 2009+ LS dry sump models. 10.5 quarts appears to be enough to run pretty much in any track with no issues, though some race teams still reported oil starvation issues. I have not heard of such an issue from any owner, though.

Fast forward to 2010, GM mitigated the issue for Camaro LS engines by increasing the sump size, increasing the total oil capacity to 8 quarts (from 6 quarts in regular LS3 engines in C6 vettes). This substantially lowers the chances of hitting the issue, but with a set of sticky tires and a track that has long turns, you're still in quite a bit of danger. Solutions?


Accusump: This has been around for quite a while. I have seriously looked into this, but ultimately have decided against it. When you search for it, there are as many horror stories as success stories with these devices. They are known to fail, might cause leaks (they stay pressurized when you shut down your engine), and it rather works 'in reaction' to oil pressure loss, meaning your engine will have suffered very low oil pressures before Accusump gets to join the party. Ultimately, I passed this option.

Staying stock: This is what my brother believes in. He says he will address it if it ever happens. It sounds irresponsible, but might actually work if your local tracks don't provide the conditions for this to happen. If your track has nothing but many sharp back-to-back turns, you would never have this issue. If your track is banked, again, you might not have the issue. It is only if you have long turns where you might be exposed. I'm looking forward to seeing if something happens to his engine when we go through the 'Caroussel' at The Ridge Motorsports Park next season.

Aftermarket dry-sump: This seems to be a good solution, but it ends up costing as much as an engine! It also usually consumes your A/C system, since the kits usually bolt onto the A/C location to power the high pressure oil pump. I question the feasibility of this option. I'd much rather sell my engine, buy an LS3 with OEM dry-sump, paying the difference. Please correct me if I'm wrong on cost of a proper dry-sump system, not to mention the intrusive mods you need to do on the engine. By the way, imagine what happens if you tear your accessory belt: your high-pressure pump would be offline. Oh, the possibilities... : )

Oil pan baffling: This is the route I chose to go with. I got the baffling from Improved Racing, and replaced the stock baffle, which is very simple in design. It has trap doors in every direction, and a more elaborate top cover to keep the oil contained right in the middle. Its manufacturer swears by its product up to 1.4 G, which should be sufficient for everyone short of a gutted race car (for which you'd probably install a dry sump system anyway). Combined with the fact that our LS3 engines run on 2 more quarts of oil compared to non-dry-sump LS3 engines running on C6 Corvettes, I think this system has a very high chance of being the ultimate solution for most. It is very cost effective, does not involve installing any critical oil line to your engine, and once installed, is a very reliable mod in terms of potential failures relative to what might happen with dry-sump pumps, accusump seals, etc. Adding on the top of this, there was recent news when the new ATS-V was announced, where GM also adopted this method to keep their new V6 TT engine well oiled. GM engineers say their engine oil baffling can let the car withstand any Gs you can subject it to with any tire you can shod it with. It's a pretty bold statement!

This pic shows the neat trap doors.


In short: My vote is on baffling. The simplest solution, and hence the most reliable. Does it do the job? I think it will, and I am emboldened by GM's adoption of the method on the new ATS-V; we'll see.

[CHMSC]

Nice info x25

[NYROC655]

Lessons learned from blowing 2 engines on my 2013 1LE while tracking at Watkins Glen......Dry Sump!

Yes, the cost was about $6k parts and labor but now that worry is gone. I can really concentrate on increasing my driving skills and times without worrying about toasting another engine. Like anything else, I chose my hobby as road course racing so I committed the time and money to make it the best experience I can.

Here is my run from last October:

[SASQUATCHelvis]

Originally Posted by X25

Oil starvation has been a major issue since LS7 and LS3 were introduced to LS engine family. Unlike LS6, which seems to be much more prone to the issue, both LS7 and LS3 (whose head design is actually based on lessons learned from LS7) suffer from oil starvation, especially during long left-hander turns where the oil might be trapped inside the heads, and oil starvation issue might occur.

To overcome the issue, LS7 comes with a dry sump. A real dry sump system would create negative crank pressures, and feature multiple scavenging locations, but GM's system is somewhat a hybrid system, and does not provide those benefits. Still, it works, and does the oiling job well. However, it was later found that the capacity (~8.5 quarts?) is still not enough to provide oil during long left-handers; the system was simply running out of oil in the container. LG Motorsports came up with an extension kit that extends the oil capacity by a few more quarts with the additional container bridged to the original container hidden in the fender, and this was also later adopted by GM itself beginning from 2009+ LS dry sump models. 10.5 quarts appears to be enough to run pretty much in any track with no issues, though some race teams still reported oil starvation issues. I have not heard of such an issue from any owner, though.

Fast forward to 2010, GM mitigated the issue for Camaro LS engines by increasing the sump size, increasing the total oil capacity to 8 quarts (from 6 quarts in regular LS3 engines in C6 vettes). This substantially lowers the chances of hitting the issue, but with a set of sticky tires and a track that has long turns, you're still in quite a bit of danger. Solutions?


Accusump: This has been around for quite a while. I have seriously looked into this, but ultimately have decided against it. When you search for it, there are as many horror stories as success stories with these devices. They are known to fail, might cause leaks (they stay pressurized when you shut down your engine), and it rather works 'in reaction' to oil pressure loss, meaning your engine will have suffered very low oil pressures before Accusump gets to join the party. Ultimately, I passed this option.

Staying stock: This is what my brother believes in. He says he will address it if it ever happens. It sounds irresponsible, but might actually work if your local tracks don't provide the conditions for this to happen. If your track has nothing but many sharp back-to-back turns, you would never have this issue. If your track is banked, again, you might not have the issue. It is only if you have long turns where you might be exposed. I'm looking forward to seeing if something happens to his engine when we go through the 'Caroussel' at The Ridge Motorsports Park next season.

Aftermarket dry-sump: This seems to be a good solution, but it ends up costing as much as an engine! It also usually consumes your A/C system, since the kits usually bolt onto the A/C location to power the high pressure oil pump. I question the feasibility of this option. I'd much rather sell my engine, buy an LS3 with OEM dry-sump, paying the difference. Please correct me if I'm wrong on cost of a proper dry-sump system, not to mention the intrusive mods you need to do on the engine. By the way, imagine what happens if you tear your accessory belt: your high-pressure pump would be offline. Oh, the possibilities... : )

Oil pan baffling: This is the route I chose to go with. I got the baffling from Improved Racing, and replaced the stock baffle, which is very simple in design. It has trap doors in every direction, and a more elaborate top cover to keep the oil contained right in the middle. Its manufacturer swears by its product up to 1.4 G, which should be sufficient for everyone short of a gutted race car (for which you'd probably install a dry sump system anyway). Combined with the fact that our LS3 engines run on 2 more quarts of oil compared to non-dry-sump LS3 engines running on C6 Corvettes, I think this system has a very high chance of being the ultimate solution for most. It is very cost effective, does not involve installing any critical oil line to your engine, and once installed, is a very reliable mod in terms of potential failures relative to what might happen with dry-sump pumps, accusump seals, etc. Adding on the top of this, there was recent news when the new ATS-V was announced, where GM also adopted this method to keep their new V6 TT engine well oiled. GM engineers say their engine oil baffling can let the car withstand any Gs you can subject it to with any tire you can shod it with. It's a pretty bold statement!

This pic shows the neat trap doors.


In short: My vote is on baffling. The simplest solution, and hence the most reliable. Does it do the job? I think it will, and I am emboldened by GM's adoption of the method on the new ATS-V; we'll see.

Awesome info! Just what I was looking for! Thanks!

[td195f]

Originally Posted by X25

Accusump: This has been around for quite a while. I have seriously looked into this, but ultimately have decided against it. When you search for it, there are as many horror stories as success stories with these devices. They are known to fail, might cause leaks (they stay pressurized when you shut down your engine), and it rather works 'in reaction' to oil pressure loss, meaning your engine will have suffered very low oil pressures before Accusump gets to join the party. Ultimately, I passed this option.

I have used accusumps on my drag race engines for 20 years and have never had an oil leak or a failure. The fact they stay pressurized when the engine is shutdown is a good thing. If you install the accusump with a solenoid valve wired to an ignition on power source the accusump will discharge it's stored oil into the engine when you turn on the key. This prelubes the engine prior to start.
The accusumps I have used float on the engine oil pressure, so as engine oil pressure drops the accusump will start to discharge oil into the system and will then recharge when oil pressure recovers. This gives additional pressurized oil volume, I use a three quart unit, in your oil system to protect the bearings if you momentarily starve the oil pump.
I have a three quart accusump with a solenoid valve controlled by a pressure switch set at 20 psi to install in my Camaro. The only place I have found where it will fit is on the top of the crossmember between the radiator and the front of the engine. This requires I fabricate a couple of custom brackets.

X25 - Did you have to lift the engine to remove the oil pan to install the Improved Racing Baffle in the pan?

[L99CAMA2011]

Originally Posted by X25

Oil starvation has been a major issue since LS7 and LS3 were introduced to LS engine family. Unlike LS6, which seems to be much more prone to the issue, both LS7 and LS3 (whose head design is actually based on lessons learned from LS7) suffer from oil starvation, especially during long left-hander turns where the oil might be trapped inside the heads, and oil starvation issue might occur.

To overcome the issue, LS7 comes with a dry sump. A real dry sump system would create negative crank pressures, and feature multiple scavenging locations, but GM's system is somewhat a hybrid system, and does not provide those benefits. Still, it works, and does the oiling job well. However, it was later found that the capacity (~8.5 quarts?) is still not enough to provide oil during long left-handers; the system was simply running out of oil in the container. LG Motorsports came up with an extension kit that extends the oil capacity by a few more quarts with the additional container bridged to the original container hidden in the fender, and this was also later adopted by GM itself beginning from 2009+ LS dry sump models. 10.5 quarts appears to be enough to run pretty much in any track with no issues, though some race teams still reported oil starvation issues. I have not heard of such an issue from any owner, though.

Fast forward to 2010, GM mitigated the issue for Camaro LS engines by increasing the sump size, increasing the total oil capacity to 8 quarts (from 6 quarts in regular LS3 engines in C6 vettes). This substantially lowers the chances of hitting the issue, but with a set of sticky tires and a track that has long turns, you're still in quite a bit of danger. Solutions?


Accusump: This has been around for quite a while. I have seriously looked into this, but ultimately have decided against it. When you search for it, there are as many horror stories as success stories with these devices. They are known to fail, might cause leaks (they stay pressurized when you shut down your engine), and it rather works 'in reaction' to oil pressure loss, meaning your engine will have suffered very low oil pressures before Accusump gets to join the party. Ultimately, I passed this option.

Staying stock: This is what my brother believes in. He says he will address it if it ever happens. It sounds irresponsible, but might actually work if your local tracks don't provide the conditions for this to happen. If your track has nothing but many sharp back-to-back turns, you would never have this issue. If your track is banked, again, you might not have the issue. It is only if you have long turns where you might be exposed. I'm looking forward to seeing if something happens to his engine when we go through the 'Caroussel' at The Ridge Motorsports Park next season.

Aftermarket dry-sump: This seems to be a good solution, but it ends up costing as much as an engine! It also usually consumes your A/C system, since the kits usually bolt onto the A/C location to power the high pressure oil pump. I question the feasibility of this option. I'd much rather sell my engine, buy an LS3 with OEM dry-sump, paying the difference. Please correct me if I'm wrong on cost of a proper dry-sump system, not to mention the intrusive mods you need to do on the engine. By the way, imagine what happens if you tear your accessory belt: your high-pressure pump would be offline. Oh, the possibilities... : )

Oil pan baffling: This is the route I chose to go with. I got the baffling from Improved Racing, and replaced the stock baffle, which is very simple in design. It has trap doors in every direction, and a more elaborate top cover to keep the oil contained right in the middle. Its manufacturer swears by its product up to 1.4 G, which should be sufficient for everyone short of a gutted race car (for which you'd probably install a dry sump system anyway). Combined with the fact that our LS3 engines run on 2 more quarts of oil compared to non-dry-sump LS3 engines running on C6 Corvettes, I think this system has a very high chance of being the ultimate solution for most. It is very cost effective, does not involve installing any critical oil line to your engine, and once installed, is a very reliable mod in terms of potential failures relative to what might happen with dry-sump pumps, accusump seals, etc. Adding on the top of this, there was recent news when the new ATS-V was announced, where GM also adopted this method to keep their new V6 TT engine well oiled. GM engineers say their engine oil baffling can let the car withstand any Gs you can subject it to with any tire you can shod it with. It's a pretty bold statement!

This pic shows the neat trap doors.


In short: My vote is on baffling. The simplest solution, and hence the most reliable. Does it do the job? I think it will, and I am emboldened by GM's adoption of the method on the new ATS-V; we'll see.

like the Idea but don't feel too sure about those hinges, looks like they would let off metal particles when it moves.

[TxBandit911]

Originally Posted by NYROC655

Lessons learned from blowing 2 engines on my 2013 1LE while tracking at Watkins Glen......Dry Sump!

Yes, the cost was about $6k parts and labor but now that worry is gone. I can really concentrate on increasing my driving skills and times without worrying about toasting another engine. Like anything else, I chose my hobby as road course racing so I committed the time and money to make it the best experience I can.

Here is my run from last October:

Well crap...

I'm planning on running at the glen next year. Now I'm worried, lol. Guess I've got some changes to make to my car before the time comes....

I may just give the baffles a try and see what happens.

[merciLSless]

Originally Posted by X25

Accusump: This has been around for quite a while. I have seriously looked into this, but ultimately have decided against it. When you search for it, there are as many horror stories as success stories with these devices. They are known to fail, might cause leaks (they stay pressurized when you shut down your engine), and it rather works 'in reaction' to oil pressure loss, meaning your engine will have suffered very low oil pressures before Accusump gets to join the party. Ultimately, I passed this option.

I would like to see the horror stories of these systems. They are fairly simple and straight forward. I am fairly active in a few different forms of motorsports and all the guys I know that use them swear by them. As for them being "Known" to fail I have only heard the opposite.

If there are leaks that just means that the installer can't put hoses together properly. I do know that after years of service they sometimes need to be rebuilt because the O-ring in the Accusump gets worn down and oil will get from the oil side to the air side but this is only after a long service life and is a fairly inexpensive service.

The other issue I have heard of "leaking" was if installed incorrectly or the precharge is not checked every oil change he unit will hydraulically lock and oil will leak out of the pressure relief valve. Hardly a product issue as much as a user error.

As for it "reacting" to oil pressure loss, you are only partially correct. Think of it like a spring. When you push the spring it compresses, when you release the pressure the spring extends right along with the decreased pressure. This is how the Accusump works.

http://gt4motorsport.com/2010/06/30/accusump-in-action/

This link is a bit old but it shows just how quickly the Accusump reacts to the pressure loss. Hardly "late to the party"

Tons of high level motorsports use the Accusump when dry sumps are not allowed, it has been around since the early 80's. Products that don't work simply don't last that long. If you actually read into the Accusump issues posted on forums it is most likely an installation, set up or use error. It's a shame that more people don't call manufacturers when they have problems and just post bad info on forums.

With all of that said, if you have the means to go dry sump do it. That is far and away the way to go. Dry sump will save you a few horsepower and you don't have to worry about oil pressure loss unless something catastrophic happens like the oil pump belt snaps.

[X25]

Originally Posted by td195f

I have used accusumps on my drag race engines for 20 years and have never had an oil leak or a failure. The fact they stay pressurized when the engine is shutdown is a good thing. If you install the accusump with a solenoid valve wired to an ignition on power source the accusump will discharge it's stored oil into the engine when you turn on the key. This prelubes the engine prior to start.
The accusumps I have used float on the engine oil pressure, so as engine oil pressure drops the accusump will start to discharge oil into the system and will then recharge when oil pressure recovers. This gives additional pressurized oil volume, I use a three quart unit, in your oil system to protect the bearings if you momentarily starve the oil pump.
I have a three quart accusump with a solenoid valve controlled by a pressure switch set at 20 psi to install in my Camaro. The only place I have found where it will fit is on the top of the crossmember between the radiator and the front of the engine. This requires I fabricate a couple of custom brackets.

X25 - Did you have to lift the engine to remove the oil pan to install the Improved Racing Baffle in the pan?

You need to lift the engine, but you don't need to disconnect or remove driveline. You can use an engine support bar for this purpose, something like this:


The actually need to be in between the strut top and the fender to avoid snapping on you during the lift.


Another way is to cut the cross-member bar under the engine oil pan. I actually bought flanges to weld into place, but ended up not using them since raising the engine to do the change is simple enough (but still makes you very nervous in the process).

[X25]

Originally Posted by merciLSless

I would like to see the horror stories of these systems. They are fairly simple and straight forward. I am fairly active in a few different forms of motorsports and all the guys I know that use them swear by them. As for them being "Known" to fail I have only heard the opposite.

If there are leaks that just means that the installer can't put hoses together properly. I do know that after years of service they sometimes need to be rebuilt because the O-ring in the Accusump gets worn down and oil will get from the oil side to the air side but this is only after a long service life and is a fairly inexpensive service.

The other issue I have heard of "leaking" was if installed incorrectly or the precharge is not checked every oil change he unit will hydraulically lock and oil will leak out of the pressure relief valve. Hardly a product issue as much as a user error.

As for it "reacting" to oil pressure loss, you are only partially correct. Think of it like a spring. When you push the spring it compresses, when you release the pressure the spring extends right along with the decreased pressure. This is how the Accusump works.

http://gt4motorsport.com/2010/06/30/accusump-in-action/

This link is a bit old but it shows just how quickly the Accusump reacts to the pressure loss. Hardly "late to the party"

Tons of high level motorsports use the Accusump when dry sumps are not allowed, it has been around since the early 80's. Products that don't work simply don't last that long. If you actually read into the Accusump issues posted on forums it is most likely an installation, set up or use error. It's a shame that more people don't call manufacturers when they have problems and just post bad info on forums.

With all of that said, if you have the means to go dry sump do it. That is far and away the way to go. Dry sump will save you a few horsepower and you don't have to worry about oil pressure loss unless something catastrophic happens like the oil pump belt snaps.

You might actually be right about installation errors likely causing the failures I have seen. Our chump race car had the Accusump installed last season, and the week before the race at The Ridge, it puked oil all over the place during a test. If it did so, say, during a hot pit stop, it could be catastrophic due to the fire hazard.

I wish I never had to touch the oil system (but did so to install the engine oil cooler). It's just very easy for something to go wrong, and OEM manufacturers also eliminate as many lines as possible to avoid any potential leaks.

[merciLSless]

Originally Posted by X25

You might actually be right about installation errors likely causing the failures I have seen. Our chump race car had the Accusump installed last season, and the week before the race at The Ridge, it puked oil all over the place during a test. If it did so, say, during a hot pit stop, it could be catastrophic due to the fire hazard.

Was this a new unit? What was the pre-charge set at? How long had it been since the pre-charge was set?

[Firefighter]

X25 I think I've seen you talk about that install in another thread. IIRC you said you bought that bar at Harbor Freight. Is that something that can be done with an engine hoist? Also it looks like you kept your hood on for the job is that correct?

Sent from my SM-G900V using Tapatalk