Oil control and monitoring vitals on LS series engines

[Mikelly]

This is what we learned back in 2005 after I blew the LS1 in my Corvette.  We ported an Accumulator to that plug in the front left corner of the block and ran the pressure switch there.  I believe it was Jeff Creech at Carolina Auto Masters that pointed me to it.  It was a better solution than the oil filter base.  But he warned me then that it would still not fully recover under some hard cornering/acceleration events with the right suspension and tires.

 

All that said, With the LS3 403 stroker I spent about $3800 going the dry sump route (The AC Nutter Kit and Parker Lines) because I figured it was cheap insurance compared to the down time, cost of the fix or replacement and I was just tired of worrying about pressure drop at places like NCCAR and Watkins Glen T6.  I monitor everything through my touchscreen dash.  The EFI/Dash combo allow for 16 analog channels to be data logged and I log everything for oil pressure, oil  temp, coolant temp, trans temp, diff temp and other parameters.  I also run a breather tank for the 4 gallon oil tank and TWIN PCV catch cans in the PCV system, per recommendations from MTI and COBRAMATT.

 

As to the PCV/ oil/crank pressure issues... After the problems I repeatedly had with the 383 stroker (which data logs helped me troubleshoot) I was done with the accusump and catch cans as the only solution for oil control.  As Cary McCallister stated about three pages back, if you're able to pull serious corner loads and road course driving is your thing, an accusump-catch cans/bandaids solution is wasting time and money.  Pete Agapoglou is having the exact same issue with his professionally build 1st gen SBC engine in his Zcar up in Connecticut and we chat offline all the time about his oiling/blowby issues.  I spend a lot of time at the track with NASA and other clubs and every times I've come across an LS equipped car in the pits with the owner and crew thrashing, it's ALWAYS puking oil and they're ALWAYS trying to fix it so the driver doesn't get back out there and get black flagged again.  These risks are not worth my time/money, which is why I think all you serious road course guys should seriously think about the solutions available.  Do NOT follow my recipe because it wasn't nearly as cost effective as Cary's.   

 

I know guys are not going to want to ditch their Accusumps because  they are an easy solution, they hope is doing the job.  They are nice devices, for some applications.  Based on what people far smarter than me have told me, they are a bandaid and not effective in all situations, some yes, but not all.  They also are slow to recover once discharged and will not be fully effective in a platform capable of 2G cornering on a busy section of track where the tank will be discharged thru much of it and the oil will be going to the wrong area.  Even if you fix the location of the oil discharge, you're still going to run out of oil recovery time, because the device simply can't recover and discharge quickly enough in some track configurations, again, according to people far smarter than me. 

 

 

 

Forgot to mention re an accumulator with an electric valve, the switch can be mounted at the blanked off point at the front left of the block where it will be more responsive to an oil pressure drop than say where the standard oil pressure switch is located. In effect if the accumulator oil input is at the point near the oil filter the accumulator electric valve will open before a potentially damaging oil pressure drop occurs at the engine itself so maintaining oil pressure. To the extent that the accumulator has the capacity to do so of course.

Edited January 10, 2015 by Mikelly

[Mikelly]

Looks like it does Keith!

 

http://www.improvedracing.com/baffles/ls1-camaro-firebird-body-racing-oil-pan-baffle-p-30.html

 

Did the baffle have a rear-facing trap door for drag racing?

[bjhines]

I would like to clear up some information about the Accusump systems.

 

I monitored oil pressure and other indicators with in-car video. My SBC oil pressure dropped on some hard right handers after braking upon turning in. The dip is brief and the engine is not under load, but it was half the turns on the course.

 

I installed a trap door pan, crank scraper, windage tray, and an EPC Accusump system,and a high pressure spring on the HV oil pump(to make the Accusump more effective).

 

There is some confusion over the basic operation of the various Accusump valves.

 

1. Mechanical valve: Valve is open during normal use. This is a 2-way(ball type)valve. The Accusump refills and discharges at the same rate. This is the least effective system. This is more of a classic PRE-OILER, system that will also provide some damping of pressure variations. The larger the better in this case. A larger volume will provide a greater damping effect.

 

2. Electric Valve: This is where there are some variations between systems. 

 

2a. Standard Electric Valve: Works exactly like the Mechanical Valve. Same limitations, Same damping effect on pressure.EDIT: It appears that the Electric valve is restricted refill as well.

 

2b. EPC Electric Valve: This is a more complex arrangement that provides some remarkable advantages for maintaining oil pressure during hard cornering/acceleration, etc.

 

The EPC valve is a restricted refill with ONE WAY, hold-until-release operation. This means that PEAK OIL PRESSURE is held in the Accusump until the EPC switch releases the highly pressurizes oil. This maximizes the volume AND pressure of the oil discharge. It maximizes the available volume of oil and the time that the Accusump can maintain oil pressure in the engine. The system refills at a restricted rate to ensure most of the available oil-pump volume is sent to the engine. The Accusump refills slowly but in plenty of time for the next turn-in.

 

I run 90 PSI oil pressure spring and a 25 PSI EPC switch. My Accusump gauge peaks out at around 80PSI, while my oil pressure gauge reads slightly lower at 65 PSI, Due to location of SBC gallery port on top of the engine vs. the Accusump further upstream in the larger -10AN plumbing. I am using the check valve(oil to engine instead of backwards to pump) and I have an oil cooler and an oil thermostat, all of it is AN-10 plumbing.

 

 

 

 

 

.

Edited January 12, 2015 by bjhines

[heavy85]

Cary - which accumulator set-up did you use on the blown up engine?

 

Going back through rereading this thread. Back a couple of pages ago there was debate on open vs vacuum CCV. When I had my engine rebuilt a couple years ago (broken ring land causing lowish compression on one cylinder and starting to scratch cyl wall) the head and combusion chamber looked really nice with minimal carbon buildup on anything. This was on a closed CCV system that I know consumes oil through it (see posts in this thread for more discussion).

[Mikelly]

If you are not already, I would recommend data logging it. Hard to tell whats going on when your eyes are looking in your mirrors or down track, thru corners and such. BTW, My EPC valve was shipped to me incorrectly marked for flow direction.

 

 

I would like to clear up some information about the Accusump systems.

 

I monitored oil pressure and other indicators with in-car video. My SBC oil pressure dropped on some hard right handers after braking upon turning in. The dip is brief and the engine is not under load, but it was half the turns on the course.

 

I installed a trap door pan, crank scraper, windage tray, and an EPC Accusump system,and a high pressure spring on the HV oil pump(to make the Accusump more effective).

 

There is some confusion over the basic operation of the various Accusump valves.

 

1. Mechanical valve: Valve is open during normal use. This is a 2-way(ball type)valve. The Accusump refills and discharges at the same rate. This is the least effective system. This is more of a classic PRE-OILER, system that will also provide some damping of pressure variations. The larger the better in this case. A larger volume will provide a greater damping effect.

 

2. Electric Valve: This is where there are some variations between systems. 

 

2a. Standard Electric Valve: Works exactly like the Mechanical Valve. Same limitations, Same damping effect on pressure.

 

2b. EPC Electric Valve: This is a more complex arrangement that provides some remarkable advantages for maintaining oil pressure during hard cornering/acceleration, etc.

 

The EPC valve is a restricted refill with ONE WAY, hold-until-release operation. This means that PEAK OIL PRESSURE is held in the Accusump until the EPC switch releases the highly pressurizes oil. This maximizes the volume AND pressure of the oil discharge. It maximizes the available volume of oil and the time that the Accusump can maintain oil pressure in the engine. The system refills at a restricted rate to ensure most of the available oil-pump volume is sent to the engine. The Accusump refills slowly but in plenty of time for the next turn-in.

 

I run 90 PSI oil pressure spring and a 25 PSI EPC switch. My Accusump gauge peaks out at around 80PSI, while my oil pressure gauge reads slightly lower at 65 PSI, Due to location of SBC gallery port on top of the engine vs. the Accusump further upstream in the larger -10AN plumbing. I am using the check valve(oil to engine instead of backwards to pump) and I have an oil cooler and an oil thermostat, all of it is AN-10 plumbing.

 

 

 

 

 

.

[bjhines]

I tackled the crankcase evacuation system as well. After a few experiments I managed to keep 5"Hg vac at all times through 2 different systems.

 

I used fabricated tall valve covers to clear rockers.

I have baffled, push in vents in both covers.

I use a catch can plumbed to both covers.

The PCV system and exhaust-pulse-scavenging both pull vac on the system catch can.

 

I tried another system as well, but ended up NOT using the electric pump. This is a fairly high current pump. It is similar to a small 12V Shop-Vac. it pulls 5" Hg VAC at 18 AMPS/12DCV. It can flow a LARGE volume and it seems resistant to oil vapors.

[JMortensen]

1. Mechanical valve: Valve is open during normal use. This is a 2-way(ball type)valve. The Accusump refills and discharges at the same rate. This is the least effective system. This is more of a classic PRE-OILER, system that will also provide some damping of pressure variations. The larger the better in this case. A larger volume will provide a greater damping effect.

 

Depends on who you're talking to, John. It's a point of contention to be sure, but Canton's own literature says the manual valve is the recommended for race cars. 

 

Lots of debate about which is the best, and I looked at quite a few threads in quite a few forums myself trying to figure out which way to go. Some people swear by the electric EPC valve, others swear by the ball valve. What's worse: running at 7000 rpm through a turn and hitting the 25 psi switch and getting the valve to open and release high pressure oil, or running a ball valve and having the pressure drop more slowly to 25 psi by the end of the turn? Seems to me it's probably 6 of 1, half dozen of the other.

 

The Manual Valve Part # 24-260: The manual valve is the simplest valve and the easiest to install. It provides

quick response time and has no restrictions. It is recommended for hard core racing applications.

Edited January 11, 2015 by JMortensen

[heavy85]

"For those looking for the convenience of an electric valve and the fast refill rate required in racing applications our (electric pressure control) E.P.C. electric valves are recommended. The pressure control system keeps the electric valve in the off position during times of normal oil pressure. With the valve in the off position it is able to quickly recharge the Accusump with oil pressure after discharge, thus being ready for the next oil surge. When the engine's oil pressure drops below the EPC Valve's preset level the valve opens and releases the stored oil in to the system. Like our standard electric valve the EPC valve can be wired to a remote dash-mounted switch or can be wired directly into the ignition so it will turn on and off automatically when the ignition is in the 'on' or the 'off' position."

 

Hmm. Sounds like just using the electric without the EPC is not recommended as the valve flows more when its turned off. This doesnt make any sense since the accumulator will start recharging as soon as the pump recovers and that would happen with the switch still on for either system. So it will be slow to refill until after the switch turns it off. It actually seems like a good feature that you want it to refill slower so the engine can build full oil pressure faster but want it to dump fast. As I read this, the best off all might just be the electric switch version without EPC.

 

I know there is debate if accumulators are adiabatic and therefore if there is an exponent in there but they are controlled by the ideal gas law so (assuming no exponent) Pressure 1 * Volume 1 = Pressure 2 * Volume 2. Say a 2 qt * air precharg at 7 PSI = 14. So if you use EPC valve and have say 80 PSI stored in there then the air volume would be 14/80= 0.175 qt with the remaining 1.825 qts being oil stored at 80 PSI waiting for whenever the EPC switch turns it on. Say you dont use EPC and its just open all the time, at the say 25 PSI point that the switch would have openend had it been EPC system you instead have 14/25 = 0.56 qt of air or 1.44 qts of oil stored and its only at 25 PSI as its come down as the oil preasure dropped.

 

What does this mean I dont know but on the surface you can see why the EPC switch system with more oil stored at higher pressure would be a good thing. However I have to wonder if you had the accumulator on all the time if the oil pressure would have even got below the switch setting in the first place? Say it takes 5 sec of sustained high G corner to lose oil pressure and assume you want to keep min of 25 PSI to keep the bearing happy, and if you are up in revs are up at the peak 80 PSI when the pump starts to starve.... then you have 1.825 - 1.44 = 0.384 qts to work with in the accumulator to supplement the oil pump. You would have to be losing almost 0.384 qt / (5 sec* 1 min/60 sec) = 4.6 qt/min through the engine for the accumulator allows the engine to get below 25 PSI. Whats a typical oil pump flowrate?

 

Either system you have the similar amount of oil to use but is it better to wait until the oil pressure to drop before using it or use it right away to help keep the pressure from dropping in the first place?

Edited January 11, 2015 by heavy85

[bjhines]

The system refills through a ONE-WAY Valve that ALWAYS allows refill at a restricted rate. The system cannot release oil until the pressure switch releases the oil, Oil which has been brought to PEAK PRESSURE between turns. 

This description explains why the EPC is sooo much more effective than the "Standard Valves". I am using the system and I have confirmed it's operation on the bench. There is no question as to how this operates or how it is better than the NON-EPC valves.

[bjhines]

 

Depends on who you're talking to, John. It's a point of contention to be sure, but Canton's own literature says the manual valve is the recommended for race cars. 

 

Lots of debate about which is the best, and I looked at quite a few threads in quite a few forums myself trying to figure out which way to go. Some people swear by the electric EPC valve, others swear by the ball valve. What's worse: running at 7000 rpm through a turn and hitting the 25 psi switch and getting the valve to open and release high pressure oil, or running a ball valve and having the pressure drop more slowly to 25 psi by the end of the turn? Seems to me it's probably 6 of 1, half dozen of the other.

 

I called CANTON Racing to clear up that statement. I was told that it was written by "Marketing people" and the technician admitted it was confusing and INCORRECT!

[bjhines]

Call them yourself. You will be instantly AMAZED at how small and shoddy their literature and print ads really are. If you want ot know exactly how their stuff works then do what I did and try ALL of the available options. I have used them ALL and I stand by my testing and observations.

[bjhines]

I also use 2 different sirens and a multi-colored warning light in the TACH that indicates operation of the system. Green is NOMINAL, Yellow and low pitch siren = Discharge, Red and high pitch siren = Less than 10 PSI oil pressure.

[bjhines]

Maintenance is a drawback. I cycle the system and recharge the air side as often as possible. I do not trust it as I have had several times on track that it did not work properly. Air leaks in the AIR gauge plumbing, and air bypassing the O-ringed piston will cause a loss of air charge. Eventually oil will end up on the AIR-side and the canister must be drained on both sides and rebuilt.

 

Observe the peak oil pressure on the OIL-pres. gauge and the AIR-charge on the Accusump gauge. The Accusump should always read higher than the Oil pressure gauge in my system. If the Accusump is lower, then the piston has bottomed out in the cylinder and cannot give you a full discharge. I have a dynamic difference in pressure due to the location of the gauge ports in the system(accusump in AN-10 lines and the Oil-P gauge on the top gallery port on SBC.

 

I considered a differential pressure switch(like the brake system warning SW). plumbed to the OIl side and AIR side of the canister to indicate piston bottoming. I could even indicate nominal Pre charge one way, and low pre charge the other way, with a DPDT differential switch. If this were installed in a factory car(Like MANY DO) with the EPC valve(Like LOTUS EXIGE DOES), I would provide an automatic Precharge pump and I would set up a Differential pressure indicator like I just described. Unfortunately Lotus DOES NOT do anything beyond Canton's original design.

 

I have also considered embedding a magnet in the piston, and using reed switches on both ends of the cylinder exterior. Problems with piston rotating away from reed locations come to mind. The magnetic/electrical bottoming indicator would reduce leak points from differential pressure plumbing. Where there is a will there is a way.

Edited January 11, 2015 by bjhines

[Savage42]

Hey guys! I thought I'd shoot you an update after getting and installing the baffles and crank scraper (goes between the wind age tray and the block/crank caps) from Improved Racing Products. I didn't have a problem with any of it by just following the instructions.

 

As you can see, there is virtually no baffling with the stock F-body setup. I was stoked to be able to pull the pan without having to mess with raising the motor, dropping the crossmember or any of that stuff, so the whole job only took a couple hours with the car on jack stands. I figure that for less than $300 and a couple hours labor, it is cheap insurance. Just wanted to pass this along with some pics.

[tube80z]

Cary - which accumulator set-up did you use on the blown up engine?

 

Going back through rereading this thread. Back a couple of pages ago there was debate on open vs vacuum CCV. When I had my engine rebuilt a couple years ago (broken ring land causing lowish compression on one cylinder and starting to scratch cyl wall) the head and combusion chamber looked really nice with minimal carbon buildup on anything. This was on a closed CCV system that I know consumes oil through it (see posts in this thread for more discussion).

 

Which one?  I think there are three now that have died around oil related issues but I may be miss counting.  We also lost an engine from counterfeit lifters that came apart.

 

All were using a 3 qt or whatever the large one is.  It was plumbed in the front of the block same place my dry sump will be.  It cost $6 for a straight AN port to fit the plug removed.  We used the manual valve and the electric valve but not the fancy EPC valve.  I'm with Mike in that if you have a couple of oil events back to back I don't know if the accumulator is going to be of much help.  I also had a chat with Kevin Johnson and he was telling me one of the issues that they ran across with accumulators was what happens when you push good non-aerated oil into the oil galley when the pump is pushing oil that has a lot of trapped air.  The short version is that it doesn't always go the way you think it does.  Can't say for sure in the LS.

 

Many people use these systems and they work fine.  But once you get to a certain performance level they won't work.  That's when you start looking at a dry sump.  A long time ago I thought they were overkill for what I did.  But tires have gotten much better and dabbling in aero has pushed corner limits beyond what the wet sump can handle.  

 

You can do a dry sump for about $1500 to 1800 with some ebay shopping and perhaps less if you get a good used pump and some deals.  If you use a 4 stage pump you'll also get a lot of vacuum in the crankcase so if you're looking at add a vaccum pump you won't need to bother.  For an autox or hillclimb car I would recommend getting a water to air heat exchanger as it will get the oil up to temp quicker.  

 

I think for street tires at a track day the scraper, pan insert, and accumulator will probably be okay.  If you add aero, higher rev, and/or slicks and the cornering is getting close to 2Gs then you're playing with fire if you don't upgrade.  When you get close to 10K in a rebuild and it costs $1500 for a race weekend you don't want to be dealing with oil issues.  And if my engine goes in the middle of a season I don't have budget to rebuild nor the time to get it fixed quickly.

 

Hope this helps,

Cary

[bjhines]

I have noticed that the discharged oil has air pockets that are audible when cycling the system with the engine off. Obviously the air separates once it is in the canister. Then you get non-aerated oil with air pockets occasionally moving with it. The discharge oil is also cooler than circulating oil.

[RebekahsZ]

Savage42-did you have to clearance the scraper any, or was it bolt-on and go? probably a good idea to spin the starter once with the pan off or rotate motor by hand (these could get messy) to be sure of crank clearance before buttoning up?

[Savage42]

I checked the clearance by rotating the crank and used 2 nuts on the very front 2 studs (since the windage tray only uses the back 8) to hold it in place while I put on the windage tray. Rotated again after all installed and no rubbing/contact. Definitely need to take the time to do that, as it's not an "idiot proof" install.

[Mikelly]

THIS is the most valuable WISDOM posted in this thread...

 

Which one?  I think there are three now that have died around oil related issues but I may be miss counting.  We also lost an engine from counterfeit lifters that came apart.

 

All were using a 3 qt or whatever the large one is.  It was plumbed in the front of the block same place my dry sump will be.  It cost $6 for a straight AN port to fit the plug removed.  We used the manual valve and the electric valve but not the fancy EPC valve.  I'm with Mike in that if you have a couple of oil events back to back I don't know if the accumulator is going to be of much help.  I also had a chat with Kevin Johnson and he was telling me one of the issues that they ran across with accumulators was what happens when you push good non-aerated oil into the oil galley when the pump is pushing oil that has a lot of trapped air.  The short version is that it doesn't always go the way you think it does.  Can't say for sure in the LS.

 

Many people use these systems and they work fine.  But once you get to a certain performance level they won't work.  That's when you start looking at a dry sump.  A long time ago I thought they were overkill for what I did.  But tires have gotten much better and dabbling in aero has pushed corner limits beyond what the wet sump can handle.  

 

You can do a dry sump for about $1500 to 1800 with some ebay shopping and perhaps less if you get a good used pump and some deals.  If you use a 4 stage pump you'll also get a lot of vacuum in the crankcase so if you're looking at add a vaccum pump you won't need to bother.  For an autox or hillclimb car I would recommend getting a water to air heat exchanger as it will get the oil up to temp quicker.  

 

I think for street tires at a track day the scraper, pan insert, and accumulator will probably be okay.  If you add aero, higher rev, and/or slicks and the cornering is getting close to 2Gs then you're playing with fire if you don't upgrade.  When you get close to 10K in a rebuild and it costs $1500 for a race weekend you don't want to be dealing with oil issues.  And if my engine goes in the middle of a season I don't have budget to rebuild nor the time to get it fixed quickly.

 

Hope this helps,

Cary

[heavy85]

Point taken on drysump but not yet in the cards for me.

 

http://www.improvedracing.com/images/testdata/Stock_vs_EGM-204.png

 

That graph is what has me thinking that without EPC might be better. When the pump loses prime its happens pretty quick and from a high RPM (and therefore oil pressure). If you wait for the EPC switch to trigger it may not be quick enough to keep oil pressure from undershooting too low. By having constant seconday supply oil pressure shouldnt drop so fast. Bjhines - you have data you can share which shows otherwise?