Road Racing - Ls1 motor dead in 2 laps at TWS

I swapped a 98 Ls1 motor into a 944 turbo. Melling 296 hi volume hi pressure pump, heads, cams, intake ~400 whp. Running R compound tires. Motor lost power and shuddered, locked up. Turns out it threw rods 5 & 6, with signs of a spun bearing. Crank was badly damaged, 2 pistons destroyed, cam locked up by debris so timing chain snapped and 5 pistons struck the valves and bent them. A piece of the rod even crushed and cut open the pickup tube.

My questions are whether this rod failure or oil/bearing failure can be remedied by an accusump, drilling the lifter buckets, over oiling the motor, etc or do I need to look at dry sumps? This is a track-only car. Thanks

http://www.picvault.info/images/537121110_ls6.jpg

the "before" picture

What RPM's were you turning? The 97-2000's had less than great rod-bolts. A baffled oil pan would also be advisable.

Running CCW? I'll take a wild guess and say it happened shortly after T7.
Running CW? maybe T4 or coming out on the straight after T2/1.

I've never really liked an Accusump. Too complicated ... too many parts and points of potential failure.

Running a quart over full on a track car has always been sage advice.

How many times have you ran the motor on track in it's current configuration?

I ran CCW the last couple of times. MOtor starting going out in T2. 1st run was 2 weeks ago test & tune 1 hour continuous no issues but I did not run on the banked straight (stayed down low on the Miata line).

I just ordered a factory crate Ls6 motor. My custom oil pan has an enclosed baffle with 4 trap doors

Dry sump LSX engines fail, as well. So, a dry sump is not necessarily a fix all remedy. Don't use a high volume oil pump. All it will do is drain the oil pan faster. I have used drilled lifter cups, hill billy pre-oiler (bladderless), ARP or LS6 rod bolts, oil cooler + an extra quart in addition to the pre-oiler successfully (knock on wood). F-body pan w/ windage tray, a higher pressure spring in the oil pump & running 15W-50 while on track.

As noted above, a dedicated baffled oil pan is also helpfull. Although, I don't use one.

Another benefit that you'll get over the 98 block that you had is the better top end oiling provided from the LS6 block due to the larger real oil passage in the LS6 block.

I ran CCW the last couple of times. MOtor starting going out in T2. 1st run was 2 weeks ago test & tune 1 hour continuous no issues but I did not run on the banked straight (stayed down low on the Miata line).

I just ordered a factory crate Ls6 motor. My custom oil pan has an enclosed baffle with 4 trap doors

High speed, high RPM left-hander is killer.

Running with Rick or MSC?

A bunch of us will be at TWS in two weeks with NASA.

Motorsports Club. Hopefully I will be at the Nasa event as well. New longblock arrives Wednesday, should have it in over the weekend

Make sure you look us up.

And I would certainly like to look over that rig of yours

I'll be with Team Texas Speed. Porsche 996 in GTS4, and Boxster S in GTS3

High speed, high RPM left-hander is killer. I can vouch for that ~ ask me how :eyes:........oil starvation is the nemesis of the LS1

Mitch is a great ear to bend and can give you some very well thought out opinions/advice

Good luck !

I'll be with Team Texas Speed. Porsche 996 in GTS4, and Boxster S in GTS3


So your hanging w/ Jay and Shannon and Kevin Mixon then.

So your hanging w/ Jay and Shannon and Kevin Mixon then.

I am building another sister car to Kevin's Boxster. The builder - Viking Motorsports - has had some incredible race results to date

Sweet setup. I agree with the oil pump. I run a blueprinted pump from Katech. What kind of RPM's are you running and what cam? I suggest sticking with the stock LS6 cam and keeping the revs down for awhile to make it last.
I have an accusump and think its better than nothing-same goes for the baffle.
What kind of oil and weight were you running? Quart over?

Since you have an LS motor come visit with the knuckledraggers in the middle garage. I'm in the Black #24 (formerly Mixon's)-you can find me in front of the white #9 bird.

I was running 15w50 and revving to 6k max, 1/2 qt over. I pushed only to about 70% since my hood was catching too much air on the front straight.

I have been reading extensively on the Corvette forums. Seems the LS6 is the hardiest of the bunch so far, with some saying it doesn't even need an accusump. A survey suggested the 10296 is the pump of choice. I am planning to add an accusump to the oil return line from the oil cooler.

Edit:

Santa's sleigh just arrived -

http://www.picvault.info/images/537121453_LS6.jpg

You must have a heckuva chimney and fireplace!

1/2 a qt doesn't tell us much. The OEM fill level varied for F-bodies from 5.5 to 6 qts over the 98-02 production run. Consider 6 qt's OEM and you should run 1 qt over for track use. Thats 7 qt's plus the volume needed for oil coolers and oil lines. I ran 7 qts in my 98 LS1 4th gen that was a street / track car. I never lost a motor.

I have 5 years experience with an LS1 track car and accusump. The accusump has not only kept the engine alive for the whole 5 years, ~30 track events per year, but it has also helped avert certain disaster on two occasions. First, the oil pan floor was sheared off on a rumble strip at Grand Sport Speedway, the driver continued racing 3/4 the way around track before looking at the oil pressure gauge. No damage to engine. Second, the LS6 oil pump gearotor shattered at PIR, again the driver drove in full spirit for some unknown amount of time before taking notice of the oil pressure. Again, motor was undamaged. This is a HKE built 470whp 347 revving to 7200rpm, with GTO front-sump oil pan in a 240SX.

If you want a scare, log your oil pressures for a lap or two. Our data-logs (Racepac gauge cluster) show the accusump being activated 10-20 separate times per lap, indicating substantial oil supply interruptions.

I have nothing but praise for the accusump system, it has performed flawlessly for over 5 years with track events nearly every weekend. In 5 years, the accusump unit has not lost a single pound of pre-charge pressure, or required any maintenance or special attention whatsoever. I don't understand Mitch's comments regarding the accusump having "too many parts." It has only one major moving part, the piston inside the body, plus the valve assembly, and one single oil line running to the engine. If that's "too complicated," then what is a dry-sump system?

If I may make a few suggestions on accusump configuration that has proven effective for us. Get the EDSC electric solenoid valve with 25psi activation pressure, and run 20psi pre-charge in the accusump unit. Also, the OEM oil pump gears are made of a brittle powdered-metal that will eventually fail from sustained high-rpm use, the standard-volume Melling pump has billet gears which have proven much more durable.

Thanks Derrick. How did you plumb the Accusump - tied into the oil return on the oil cooler lines?

Thanks Derrick. How did you plumb the Accusump - tied into the oil return on the oil cooler lines?

Yes, it's T'd into the cooler line downstream of the filter. Make sure the accusump only sees filtered oil! Our accusump taps into the oil circuit at the remote filter mount for convenience. We used Derale remote filter mount 25709 which has 2 sets of ports - the accusump taps into the unused filter outlet port, which would normally be capped off with a plug.

Sucks to hear about yet another dead engine due to oiling...

I vote LS6, but with upgraded bolts, etc. Toss a deec 3+1 dry sump on there w/ 3 gallon tank or get an accusump with a sizable reservoir.

As with all oiling and a LSx engine, engines can still fail from oiling be it dry sump or accusump. Get a pressure alarm rigged up or eagle eye the pressure gauge at all times.

My 3Q Accusump arrived with EPS switch. My remote oil filter has open ports to tie into. I also found this link to a modified windage tray and crank scraper. Was wondering if anyone has tried these:

http://www.crank-scrapers.com/Chevrolet_LS.html

http://www.crank-scrapers.com/12558189-MODIFIED-TRAY-LS-J.jpg
http://www.crank-scrapers.com/12558189-MODIFIED-TRAY-LS-A.jpg

The scraper probably wouldn't hurt to have, but also it probably won't help anything either. We've been using the factory tray and pan baffle, the many aftermarket ls1 oil control devices floating around these days haven't been developed under any real testing or research environment. They *look* more sophisticated than the oem pieces they replace, but it seems that's all they're engineered to do.

Will the LS6 pan fit in the Porsche? Its part of the secret sauce that makes that makes the LS6 work.

I finally caved and went dry sump on my formerly baffled and accusumped LS2 (w/LS1 pan) couldn't keep up with high g turn oil pressure drops. Track only, R6 tired E36 M3.

Rock solid pressure now but not inexpensive.

John

only custom pans fit in the 944. The dry sump pans all look like they would fit

The scraper probably wouldn't hurt to have, but also it probably won't help anything either. We've been using the factory tray and pan baffle, the many aftermarket ls1 oil control devices floating around these days haven't been developed under any real testing or research environment. They *look* more sophisticated than the oem pieces they replace, but it seems that's all they're engineered to do.

No disrespect but some people that make aftermarket oil control parts have made them for hundreds of other engines and do have an understanding of why the factory piece was designed the way it was and how to enhance it.

If you have an accusump activating numerous times during an event, that is an indication of serious oiling issues. At a bare minimum it means that a great deal of power is being lost churning oil. What are your oil temps out of curiosity? I am glad an accusump has worked in practice for you.

I swapped a 98 Ls1 motor into a 944 turbo. Melling 296 hi volume hi pressure pump, heads, cams, intake ~400 whp. Running R compound tires. Motor lost power and shuddered, locked up. Turns out it threw rods 5 & 6, with signs of a spun bearing. Crank was badly damaged, 2 pistons destroyed, cam locked up by debris so timing chain snapped and 5 pistons struck the valves and bent them. A piece of the rod even crushed and cut open the pickup tube.

My questions are whether this rod failure or oil/bearing failure can be remedied by an accusump, drilling the lifter buckets, over oiling the motor, etc or do I need to look at dry sumps? This is a track-only car. Thanks

You probably need to look at drysumps.

However, you first need to look at the front to rear balance of your suspension. You will need to know if you have a car that oversteers or understeers or is so close that you can vary it by your style of driving. This will affect where the oil tends to go in high speed lateral acceleration hence the optimal location of scavange ports.

The heritage of the 944 is the 928 with its legendary oil issues that the architecture of the LS emulates in many ways. There is one driver, probably in the world, that successfully "babies" the stock wetsump 928 into surviving long term on the track, competing against Corvettes usw., Mr. Mark Kibort.

His style of driving in turns makes the oil tend to pool in the forward corner of the engine where the aeration is great but sufficiently allowed for by the Porsche engineers. When a driver's style tends to oversteer then the oil pools in the rear corner where it is is violently trapped by the rotating assembly and the engine will eventually expire.

You could be "safer" and use a multistage system having scavange ports at , minimally, both ends of the pan with a scraper directing flow into the port. If you neglect this study/contemplation you could end up with a system that so overaerates the oil in extrema that the holding tank with its hydrocyclone cannot properly condition the oil in the time alloted by the turnover rate of the oil volume. This appears to be the problem with the stock drysump setup.

Dry sump if you stay wet i would run an accusump for safety.

HLJ-
OS/US has not effect on where the oil ends up, not sure who told you that. Yes the front and rear lateral accelerations will be different, but the accel VECTOR will be the same direction, hence the oil will be in the same spot.

Dry sump if you stay wet i would run an accusump for safety.

HLJ-
OS/US has not effect on where the oil ends up, not sure who told you that. Yes the front and rear lateral accelerations will be different, but the accel VECTOR will be the same direction, hence the oil will be in the same spot.

Partially fill a rectangular container of water and place it on a turntable. Adjust the attitude of the container to reflect oversteer or understeer of the chassis hence the motor in a longitudinal mounting.

Yes, there is a prevailing vector but the reaction against the walls of the sump provide a component that will push the bulk of the oil to the front or rear corner of the pan. It is easy to miss this. The pattern makes an interesting curve. I hereby name this effect the "Kibort Effect." I am sure he will not mind though as a dealer for Amsoil he has been pondering how to attribute the longevity of his 928 engines to their fine products for many years now. Many other drivers have offered to drive his cars and demonstrate how they will be able to force his engines to expire from oiling problems in the 2/6 rod bearings. I have little doubt that they would succeed rapidly.

Better yet, simply perform the experiment and let empirical physics be your guide.

I am not going to lie, you have the gears turning in my mind. However, I am still pretty sure that the effects of 100% braking, then turning in to blend 100% lateral accel then blend to 100% forward accel creates a force that overcomes the small differences that occur from over/under steer. Not to mention that the car should never really do any of those things in any large amount in a properly setup car.

I am not going to lie, you have the gears turning in my mind. However, I am still pretty sure that the effects of 100% braking, then turning in to blend 100% lateral accel then blend to 100% forward accel creates a force that overcomes the small differences that occur from over/under steer. Not to mention that the car should never really do any of those things in any large amount in a properly setup car.


I thought about the situation with the 928 for a long time. I solved the problem with the wet sump but then contemplated why Mark would have success with stock parts -- whilst still driving very competitively. There were quasi-factory sponsored European racers in the early/mid 90s that managed to get their wetsumped cars to survive nearly a full season. It is unclear, though, whether these engines only used stock parts -- evidence tending towards them NOT simply using stock parts. I suspect that Porsche (perhaps contracted out to Cosworth?) began studying the problem using a multi-axis dyno and instructed the team how to set up their car and drive it for best longevity.

As far as other factors, they are numerous. For example, when a car leans in the turns this generates apparent acceleration via a changed orientation of the system. Similarly with drag racers that lift the front end -- the apparent G's in the rear of the pan are altered.

No disrespect but some people that make aftermarket oil control parts have made them for hundreds of other engines and do have an understanding of why the factory piece was designed the way it was and how to enhance it.

If you have an accusump activating numerous times during an event, that is an indication of serious oiling issues. At a bare minimum it means that a great deal of power is being lost churning oil. What are your oil temps out of curiosity? I am glad an accusump has worked in practice for you.

No argument, but I'm speaking specifically about profiled crank scrapers, which are generally shown to be ineffective in the 3 SAE papers I've read about them, and the aftermarket oil pan baffles available for the LS1, specifically the Improved Racing products, who's customers and representatives I've talked to at length.

The accusump does not fix any oiling problems, it only fills in the gaps, and in many cases like ours, that's good enough. It's not a perfect solution, but the oiling system doesn't have to be perfect to work well enough. I have no illusions about this. To answer your question, the highest oil temp we see is 250F on hot days with a moderate cooler, 210F water. The LS1 has some serious oil supply and entrainment problems for sure, but with the accusump our engine has lived fine for 5+ years at an improbable 7200rpm and with reasonable oil temps, this end product shows the oiling system to be fully adequate, not one with "serious oiling issues" as you put it.

The accusump-supplemented wet-sump is inexpensive, simple, maintenance free, and reliable, all qualities we have not seen in dry sump systems. An acquaintance of ours has lost 2 engines in the same 5 years from throwing dry-sump belts, and he's also had to rebuild the pump twice to fix leaks in the housing and shaft seals.

LS1's which turn over ~7200rpm in RR apps certainly need dry-sump if only to get rid of the OEM direct-drive gearotor oil pump, which is by then out of it's range of operation. A good dry sump will also be worth a few extra horsepower by reducing oil entrainment in the rotating assembly. Extra ground clearance, larger oil capacity, consistent oil supply to pump inlet, lower oil aeration (if designed right). . . All these are good qualities of a dry-sump that should be considered as well.

No argument, but I'm speaking specifically about profiled crank scrapers, which are generally shown to be ineffective in the 3 SAE papers I've read about them,

I would love to read those SAE papers. Do you have the publication numbers? A couple papers that I read put out by MIT on windage trays had errors in the analysis. The errors were serendipitous though in that corrected extrapolation of the data leads to scrapers. This helps explain why many oems include profiled scrapers in their engine designs.


... and the aftermarket oil pan baffles available for the LS1, specifically the Improved Racing products, who's customers and representatives I've talked to at length.

Well, your comments were made in juxtaposition with pictures of a modified factory tray and aftermarket scraper designed to work within it. When the well used engine was examined prior to its design the witness marks from the entrained oil showed weaknesses in how the OEM device functioned with respect to flow patterns. You can see similar witness marks in this general type of louvered tray from other marques and engines.



The accusump does not fix any oiling problems, it only fills in the gaps, and in many cases like ours, that's good enough. It's not a perfect solution, but the oiling system doesn't have to be perfect to work well enough. I have no illusions about this. To answer your question, the highest oil temp we see is 250F on hot days with a moderate cooler, 210F water. The LS1 has some serious oil supply and entrainment problems for sure, but with the accusump our engine has lived fine for 5+ years at an improbable 7200rpm and with reasonable oil temps, this end product shows the oiling system to be fully adequate, not one with "serious oiling issues" as you put it.

The failure of your gerotor could be directly attributed to repeated shock loading with heavily aerated oil. That's a serious oiling issue. That rpm level is also hardly extraordinary. Some thirtyfive to forty years ago the stock 928 engine bottom end was designed to run at that rpm all day long -- on the dyno. I also wonder how the power output via the valvetrain was affected. At an activation of sub 25 psi that means the solution is well beyond supersatured for the given pressure and there are free air bubbles in the circuit. There are a number of SAE papers on that topic. I have the numbers if you are interested.



The accusump-supplemented wet-sump is inexpensive, simple, maintenance free, and reliable, all qualities we have not seen in dry sump systems. An acquaintance of ours has lost 2 engines in the same 5 years from throwing dry-sump belts, and he's also had to rebuild the pump twice to fix leaks in the housing and shaft seals.


I suspect you would have matched his failure rate but you were saved by divine intervention, i.e. a driver finally looking at a gauge and by then switching to a stronger gear able to take the severe abuse. Accusumps are wonderful products but they were designed for intermittent and extraordinary use.



LS1's which turn over ~7200rpm in RR apps certainly need dry-sump if only to get rid of the OEM direct-drive gearotor oil pump, which is by then out of it's range of operation. A good dry sump will also be worth a few extra horsepower by reducing oil entrainment in the rotating assembly. Extra ground clearance, larger oil capacity, consistent oil supply to pump inlet, lower oil aeration (if designed right). . . All these are good qualities of a dry-sump that should be considered as well.

Oh I see, you are Kevin Johnson, of Ishihara-Johnson Crank Scrapers, who produces the crank scrapers pictured and referenced above. I don't have the time to spend arguing here.

Oh I see, you are Kevin Johnson, of Ishihara-Johnson Crank Scrapers, who produces the crank scrapers pictured and referenced above. Been watching those server logs have you? I see that chip on your shoulder now. . . . I take issue with your coversion of your agenda and your beguiling and subversive rhetoric.

I have never tried to conceal who I am, KLJohnson are my initials and last name. As for the chip on my shoulder, I take the topic of oil control seriously. I will be and have always been happy to read SAE articles. It is telling, perhaps, that you do not properly cite them when asked. Thank you, though, for "beguiling and subversive rhetoric." My my. Information warfare is one application of theoretical linguistics and logic.

I went through my server log because I had the odd experience of a shop calling and asking to resell my products based on pricing and information from at least four years ago that they said was on my website. They were correct, in a way. They were old pages I left up in the public access section but unlinked to my current website.



It is rather amusing watching you describe in detail how our motor can't work according to your principles, and flying in the face of "massive oiling problems" that are presumably "fixed" with your product.

No, I simply have a bit more background on the topic than you. I also payed attention to what you wrote.



And yet our motor does work, even exceeding generous expectations on longevity and durability. I appreciate a good working theory very much, but your assertions here are sorely biased and lacking in sufficient knowledge and experience with the particular motors being discussed.

Good day.

I am glad that you are happy with the performance of your engine. I deal with people all the time who would treat it as a starting point.

I am perfectly happy to tell people it is time to move to a dry sump just as I have done here.

Ok, if you review the patent by Evans, 5,014,820, of the newer, simpler accumulator design there is a glaring issue.

Oil held in the accumulator under a given pressure is in communication/contact with a free air bubble that will seek to establish an equilibrium of approximately 9% per bar dissolved air in the oil. When this supersatured oil is released by design into a lower pressure circuit the dissolved air will evolve out into free air bubbles until the imbalance is resolved. This is exactly the opposite of what you want -- you want neat oil with little to no dissolved air in it.

Aggravating this is when the cylinder is recharged with aerated oil.

The accumulator is designed for intermittent and extraordinary use.

Good day.

It is hard for me to take anything seriously when the name "Mark Kibort" is introduced. He name evokes the same kind of response in the Porsche racing community as Vince Shlomi.

It is hard for me to take anything seriously when the name "Mark Kibort" is introduced. He name evokes the same kind of response in the Porsche racing community as Vince Shlomi.

You have to give him credit where it is due and clearly this is the case. If you are actually trying to investigate empirical evidence and push knowledge forward that is.

You have to give him credit where it is due and clearly this is the case. If you are actually trying to investigate empirical evidence and push knowledge forward that is.

I think your crank scraper is a sound idea. The price is reasonable as well.
I am searching for anectodal evidence from users to see if the theory has worked out for road-racing in the LS1. I have used one in an E36 in the past.

Kibort is one of those folks who doesn't even realize he is the laughing stock for an entire community. Every one of his posts is self-deprecating. It is truly amazing.

Not a sound idea (Kibort):

http://www.electricsupercharger.com/images/product-super-eram-flow.gif

Clayp-did you make it to TWS? I talked to a guy with a red/silver 944 with an LS1 a little but that wasn't you. He was having some oil consumption (PCV) issues and told him to come check out my setup but he didn't stop by. I'm still experimenting as I went to a later model engine valley cover with a fixed orifice valve so I dont' have a PCV anymore. I routed normal pcv lines to the vented catch tank and then to the throttle body. Capped the front of the valve cover. I'll check the tank this weekend and oil in the intake tract.

I just ordered a factory crate Ls6 motor. My custom oil pan has an enclosed baffle with 4 trap doors

Where did you pick up the new LS6 and if you don't mind sharing, what did it cost? I've been looking and it seems the cost have gone up significantly in the last 9 months.

A PM response is fine, also.

Thanks
Dave Algozine

I think your crank scraper is a sound idea. The price is reasonable as well.
I am searching for anectodal evidence from users to see if the theory has worked out for road-racing in the LS1. I have used one in an E36 in the past.

Kibort is one of those folks who doesn't even realize he is the laughing stock for an entire community. Every one of his posts is self-deprecating. It is truly amazing.

Not a sound idea (Kibort):

http://www.electricsupercharger.com/images/product-super-eram-flow.gif

Thanks -- it seems like I almost wrote a dissertation somewhere on the Corvette LS pan and primary and secondary windage trays and failure modes along with the issues in the galley.

I know all about Mark but I am willing to listen when people give reliable data.

Also, back in the 1950s my Father bolted an industrial electric supercharger on his Nash Rambler with the straight six. He grew up in Romulus and my Grandfather assured me he picked up plenty of speeding tickets with it -- even when Telegraph had no exact speed limit. At Willow Run it had a top speed of about 140mph. Sometime during that run the vacuum over the car sucked off the convertible top. Maybe his car was the subject of the Beep, Beep song. http://www.youtube.com/watch?v=o1c4QZGQw5o

I know that is a bit different from an ERam but a lot of people scoff at electric superchargers in principle. Oh well.

My 3Q Accusump arrived with EPS switch. My remote oil filter has open ports to tie into. I also found this link to a modified windage tray and crank scraper. Was wondering if anyone has tried these:

http://www.crank-scrapers.com/Chevrolet_LS.html

http://www.crank-scrapers.com/12558189-MODIFIED-TRAY-LS-J.jpg
http://www.crank-scrapers.com/12558189-MODIFIED-TRAY-LS-A.jpg

I also use the 3QT accusump, with the crank scraper above, also use the Kevko Road Race baffled oil pan, drilled the lifter trays, high pressure oil pump oil pressure has been rock solid!

A friend with the same car as mine, blew his ls6 in 2 laps at CMP a year ago, got a new motor and new accusump and hasnt looked back!

I have an Accusump too. Picked it up over twenty years ago. Different animal, which is why it is worth reading the discussion section of Evans' later patent.

Just pulled it off the shelf. It is still precharged after twenty years. Quality piece.

Anyway, the idea is that not all parsimonious engineering alterations are for the better.

Where did you pick up the new LS6 and if you don't mind sharing, what did it cost? I've been looking and it seems the cost have gone up significantly in the last 9 months.

A PM response is fine, also.

Thanks
Dave Algozine

Dave I grabbed one of the last ones that Dahmer Powertrain had. I have seen some other places indicating existing stock but I don't recall who. 3.5k after credit given for a core