drz

iTrader: (3)

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.

OKcruising

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.

clayp

iTrader: (2)

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

drz

iTrader: (3)

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.

Maynor

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

clayp

iTrader: (2)

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

KLJohnson

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.

KLJohnson

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.

MomentumAutosports

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.

KLJohnson

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.

MomentumAutosports

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.

KLJohnson

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.

drz

iTrader: (3)

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.

KLJohnson

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.

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 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.


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.

drz

iTrader: (3)

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.

KLJohnson

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.


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


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.

KLJohnson

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.

clayp

iTrader: (2)

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.

KLJohnson

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.

clayp

iTrader: (2)

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):