New oil control solution for Race/ORR/SC/Stroker/GTS/GT/CS/SE/S4/S3 928 Engines
#106
IMO even 800/575 is way too soft for a racer. I'm about twice those numbers and still bottom out although sitting low is a factor.
I've run something like 600/400 and it was brutal on the underside and that's at 2780 race weight.
BTW, it's not the oil pan that sees any contact,even with a pan spacer. The sway bar mounting will be the main thing hitting.
I've run something like 600/400 and it was brutal on the underside and that's at 2780 race weight.
BTW, it's not the oil pan that sees any contact,even with a pan spacer. The sway bar mounting will be the main thing hitting.
#107
In my car I've worn swaybar mount bolts away, scraped the exhaust, front splitter and lower bellhousing but have never had a scratch on the oil pan itself.
#109
Do you know how early the deeper pans were withdrawn?
Greg, Rob,
Great work at achieving an affective solution which meet all your criteria. Very uncommon for this to happen without compromise. One might say the compromise was cost, but this wasn't a part of your criteria. Well done!
#110
A race car doesn't bottom as though a giant hand pushed it downward. They are always in some sort of turn. I've never seen a dip on a straight that would bottom a car.
In my car I've worn swaybar mount bolts away, scraped the exhaust, front splitter and lower bellhousing but have never had a scratch on the oil pan itself.
In my car I've worn swaybar mount bolts away, scraped the exhaust, front splitter and lower bellhousing but have never had a scratch on the oil pan itself.
#111
Looking at some of the pictures in Brian's book might help someone with extensive knowledge of small differences in parts.
On page 62 there is a picture of a deeper sump identified as the stock engine. It is unclear when this photo was taken.
Edit: The fan blade on page 62 appears to be made of off-white plastic (?). On the factory floor in 1977 the fan blades appear to made of alloy.
On page 71 there are pictures of workers assembling parts. These are later shallow sump engines.
If someone reading this is close to the Porsche factory museum the exploded/disassembled engine display has a deeper sump. Perhaps it is possible to read the part number.
On page 62 there is a picture of a deeper sump identified as the stock engine. It is unclear when this photo was taken.
Edit: The fan blade on page 62 appears to be made of off-white plastic (?). On the factory floor in 1977 the fan blades appear to made of alloy.
On page 71 there are pictures of workers assembling parts. These are later shallow sump engines.
If someone reading this is close to the Porsche factory museum the exploded/disassembled engine display has a deeper sump. Perhaps it is possible to read the part number.
Last edited by Kevin Johnson; 05-07-2011 at 12:25 AM.
#112
Kevin where do you get this stuff??? have you ever ridden in a 928 or driven one ?? The old very brown 1980 which is very low and runs 225x50x15 little bitty tires NEVER bottoms out the oil pan, now true I have ground off a couple tie down brackets and the heads off the bolts but the oil pan is just fine. and I have done some pretty rude things like shear off a lower ball joint and have a front wheel collapse and blowing a tire at 60 MPH or so. The pan was fine.
#113
Kevin where do you get this stuff??? have you ever ridden in a 928 or driven one ?? The old very brown 1980 which is very low and runs 225x50x15 little bitty tires NEVER bottoms out the oil pan, now true I have ground off a couple tie down brackets and the heads off the bolts but the oil pan is just fine. and I have done some pretty rude things like shear off a lower ball joint and have a front wheel collapse and blowing a tire at 60 MPH or so. The pan was fine.
I get this stuff by trying to look carefully at the parts related to oil control. When you do a tech inspection now on a 928 you'll really know what to look for.
#115
Great work as always Greg.
At the moment I rebuild my euro s engine. These engines last here in Germany very long without problems.I think related to your findings and the little space in the heads of the two valve engines.
After changing the passage to 2/6 and building a very improved oil cooling to avoid warping valve covers these cars run as race cars flawless.
I think about my other engine and wait for your solution for the s 3.Here I have a lot carbon build up on the valves and pistons.
The rings are bad but i don´t know if all the build up comes from the bottom or over the intake?
This is a great thread and a real source for pushing our cars in the next decade.Good used engines are rare especially 4 valve here in Germany.
At the moment I rebuild my euro s engine. These engines last here in Germany very long without problems.I think related to your findings and the little space in the heads of the two valve engines.
After changing the passage to 2/6 and building a very improved oil cooling to avoid warping valve covers these cars run as race cars flawless.
I think about my other engine and wait for your solution for the s 3.Here I have a lot carbon build up on the valves and pistons.
The rings are bad but i don´t know if all the build up comes from the bottom or over the intake?
This is a great thread and a real source for pushing our cars in the next decade.Good used engines are rare especially 4 valve here in Germany.
#116
... in the heads it becomes a solid stream of oil from the filling the provent from the rocked cover vents until it overflows onto the floor.
If you place clear tube in the vent line you can see the stream of oil.
My original plan was to provide the sump with an engine vacuum source for this provent, from either a pump or exhaust venturi , but quickly despatched the idea after the volume of oil was so massive it would overwhelm anything in the vacuum line and probably either plugg it up or have it flow out the exhaust, either way the result is catastrophic.
If you place clear tube in the vent line you can see the stream of oil.
My original plan was to provide the sump with an engine vacuum source for this provent, from either a pump or exhaust venturi , but quickly despatched the idea after the volume of oil was so massive it would overwhelm anything in the vacuum line and probably either plugg it up or have it flow out the exhaust, either way the result is catastrophic.
I used the 4 vents in the heads to the provent, once the engine reached 6000 rpm the oil output from these became scary, so any mapping beyond this was a waste of time, for all you with a stock 32 valve reving beyond this regularly, if you saw what happened in my dyno cell you wouldnt want repeat it .
Kevin this particular engine has one of your scapers installed, whilst I am sure it has helped it does not fix the inherent design flaw this engine posesses . In addition to this I installed the pressure limiting valves from Porsche that you mentioned , which again suggests to me that the issue is not pressure related, it is flow and the inability to return the oil to the sump.
Kevin this particular engine has one of your scapers installed, whilst I am sure it has helped it does not fix the inherent design flaw this engine posesses . In addition to this I installed the pressure limiting valves from Porsche that you mentioned , which again suggests to me that the issue is not pressure related, it is flow and the inability to return the oil to the sump.
My next project engine will again contain your scrapers and the valves, but it also have the head scavenge system installed to complete the loop.
I beleive that the best system is to dry sump the engine , because this system will scavenge all areas of the engine I know that it is best , but with all the time that I have spent trying to fit find a place for the tank (I believe it needs to be 20 litres) I cannot locate a place and still maintain the stock look, which is important maintainance of the value of the GT .
My theory will be well tested when this system goes into the club race car .
I beleive that the best system is to dry sump the engine , because this system will scavenge all areas of the engine I know that it is best , but with all the time that I have spent trying to fit find a place for the tank (I believe it needs to be 20 litres) I cannot locate a place and still maintain the stock look, which is important maintainance of the value of the GT .
My theory will be well tested when this system goes into the club race car .
#117
John, interjection. I spent the last few hours examining the situation yet again. If you are saying that the situation with oil ejection on your engine is the same as this stituation then you are mistaken about the oil not containing air. If you look at the picture and the video that Rob put up the oil is quite clearly very aerated and this is not simply the effect of being drawn into a transfer pump. Scavange pumps will typically mix air into oil but these images are prior to the oil entering the pump gears/rotors.
No one is trying to say there isn't any air mixed with the oil...inside the valve covers is a mixture of oil/air that is being picked up...of course it will have air. About the testing I did, what was ejected wasn't foamy....like you see in portions of Louis Ott's video. It was mostly solid oil, mixed with air.
Perhaps the problem here, is with the "terms" we are using. Perhaps we need to discuss this in more specific terms. I consider aerated oil to be foamy and filled with lots of little bubbles. Put some oil in your blender and turn it on...that's aerated. Pour a fresh bottle of Coke into a glass...that's aerated. I consider "mixed" oil/air to be "pretty much solid oil, mixed with air. The two are not completely together, but are independant, still. The oil that was coming out of the valve covers, on my dyno testing was not aerated, it was mixed. The oil that was coming out of the vent for the crankcase....now that was aerated.
I believe a Provent, from the appearance and size, is meant to centrifuge out oil droplets from an air stream rather than centrifuge out air bubbles from an oil stream. The hydrocyclones in the dissected Honda tank were fed by pumps. Plus, applying a vacuum source to aerated oil will increase the bulk volume still further.
How much oil did you fill the sump with?
Seriously, I think we can assume that John Gill and I are beyond that point. Somehow, having communicated with John, I think he might be more intelligent than to overfill the sump.
A basic volume calculation in this described system would need to include (guesstimate) 20 to 30% free air increasing the bulk volume of the oil.
No doubt there is still air in there...but both John and I seem to agree that there is a ****pot of oil in the heads, at higher rpms.
No one is trying to say there isn't any air mixed with the oil...inside the valve covers is a mixture of oil/air that is being picked up...of course it will have air. About the testing I did, what was ejected wasn't foamy....like you see in portions of Louis Ott's video. It was mostly solid oil, mixed with air.
Perhaps the problem here, is with the "terms" we are using. Perhaps we need to discuss this in more specific terms. I consider aerated oil to be foamy and filled with lots of little bubbles. Put some oil in your blender and turn it on...that's aerated. Pour a fresh bottle of Coke into a glass...that's aerated. I consider "mixed" oil/air to be "pretty much solid oil, mixed with air. The two are not completely together, but are independant, still. The oil that was coming out of the valve covers, on my dyno testing was not aerated, it was mixed. The oil that was coming out of the vent for the crankcase....now that was aerated.
I believe a Provent, from the appearance and size, is meant to centrifuge out oil droplets from an air stream rather than centrifuge out air bubbles from an oil stream. The hydrocyclones in the dissected Honda tank were fed by pumps. Plus, applying a vacuum source to aerated oil will increase the bulk volume still further.
How much oil did you fill the sump with?
Seriously, I think we can assume that John Gill and I are beyond that point. Somehow, having communicated with John, I think he might be more intelligent than to overfill the sump.
A basic volume calculation in this described system would need to include (guesstimate) 20 to 30% free air increasing the bulk volume of the oil.
No doubt there is still air in there...but both John and I seem to agree that there is a ****pot of oil in the heads, at higher rpms.
While I see some critical assessments of what my research has shown, you never seem to come out and say what it takes to fix the oiling problem. Perhaps you could be specific. Are you saying that your windage tray will solve the problem? Are you saying that the oil to the heads needs to be restricted and a windage tray added? A precise statement about what it takes to solve the 928 oiling problems, from you, would be nice. By doing that, you could solidify your place in the 928 world and people could buy whatever you think will solve the problem.
I'm coming out and saying the following to everyone. This is a complex problem, with several steps required to fix it. Follow these steps and the problem with oil supply at high rpms will be fixed. Follow these steps and you won't be "pumping" oil into the intake system of your 928. Follow these steps and you won't have to think you might have solved the problem, but know that these pieces have been tested and actually do solve the problem.
That is what this thread is about.
#118
Greg, I apologize -- I had not read the long, now-locked, thread from February. As I have said a number of times over the last few years I do not have the time to regularly follow the Rennlist, nor really any list. I can appreciate now why you see my remarks to be strange and maybe devious (??).
In that thread you said the issue with the 2/6 bearings is that they receive the oil last after the engine sucks air and the passage needs to refill. Yes, I remember your soaker garden hose analogy from many years ago.
This is a great theory but it does not match what happens during these rod failures. The pressure does not drop to zero requiring the passage to be refilled. As I remarked at that time -- it, the hose, is already full which simply means the 2/6 bearings receive highly aerated oil first. What does happen is that the pressure drops and any number of SAE papers explain this to be an indication of heavy aeration of the oil and why rod bearings can fail because of it. There are a number of aeration measuring devices available if you wanted to test a 928 engine to destruction while measuring the pressure in bedplate passages. You saw this on the dyno when the pressure steadily dropped.
The other thing that was heavily discussed in the closed thread was that the cavity in the first bay is to blame for many problems. Obviously I strongly agree. Also, if you want to read some more SAE papers there are many that indicate increased rpm will increase aeration. It is not controversial. Scrapers, for example, simply shift equilibrium levels.
So, really, I am not trying to steal your fire or copy your products or whatever else. You focus on one engine. That's great but there is a huge "database" out there. I really pissed off some slant six owners when I brought up technology from other engines and how it could apply. Hey, the designer of the slant six, Weertman, called it his first clean sheet engine and was proud that it used established design principles from other engines. Head-smack.
Anyways, good luck with the transfer pump. It does look like a quality item and I think it is wonderful that it will help conserve the diminishing supply of engines. When I suggest transfer pumps to racers there is usually a problem because it is considered illegal in their class. Go figure.
In that thread you said the issue with the 2/6 bearings is that they receive the oil last after the engine sucks air and the passage needs to refill. Yes, I remember your soaker garden hose analogy from many years ago.
This is a great theory but it does not match what happens during these rod failures. The pressure does not drop to zero requiring the passage to be refilled. As I remarked at that time -- it, the hose, is already full which simply means the 2/6 bearings receive highly aerated oil first. What does happen is that the pressure drops and any number of SAE papers explain this to be an indication of heavy aeration of the oil and why rod bearings can fail because of it. There are a number of aeration measuring devices available if you wanted to test a 928 engine to destruction while measuring the pressure in bedplate passages. You saw this on the dyno when the pressure steadily dropped.
The other thing that was heavily discussed in the closed thread was that the cavity in the first bay is to blame for many problems. Obviously I strongly agree. Also, if you want to read some more SAE papers there are many that indicate increased rpm will increase aeration. It is not controversial. Scrapers, for example, simply shift equilibrium levels.
So, really, I am not trying to steal your fire or copy your products or whatever else. You focus on one engine. That's great but there is a huge "database" out there. I really pissed off some slant six owners when I brought up technology from other engines and how it could apply. Hey, the designer of the slant six, Weertman, called it his first clean sheet engine and was proud that it used established design principles from other engines. Head-smack.
Anyways, good luck with the transfer pump. It does look like a quality item and I think it is wonderful that it will help conserve the diminishing supply of engines. When I suggest transfer pumps to racers there is usually a problem because it is considered illegal in their class. Go figure.
#119
Kevin:
While I see some critical assessments of what my research has shown, you never seem to come out and say what it takes to fix the oiling problem. Perhaps you could be specific. Are you saying that your windage tray will solve the problem? Are you saying that the oil to the heads needs to be restricted and a windage tray added? A precise statement about what it takes to solve the 928 oiling problems, from you, would be nice. By doing that, you could solidify your place in the 928 world and people could buy whatever you think will solve the problem.
I'm coming out and saying the following to everyone. This is a complex problem, with several steps required to fix it. Follow these steps and the problem with oil supply at high rpms will be fixed. Follow these steps and you won't be "pumping" oil into the intake system of your 928. Follow these steps and you won't have to think you might have solved the problem, but know that these pieces have been tested and actually do solve the problem.
That is what this thread is about.
While I see some critical assessments of what my research has shown, you never seem to come out and say what it takes to fix the oiling problem. Perhaps you could be specific. Are you saying that your windage tray will solve the problem? Are you saying that the oil to the heads needs to be restricted and a windage tray added? A precise statement about what it takes to solve the 928 oiling problems, from you, would be nice. By doing that, you could solidify your place in the 928 world and people could buy whatever you think will solve the problem.
I'm coming out and saying the following to everyone. This is a complex problem, with several steps required to fix it. Follow these steps and the problem with oil supply at high rpms will be fixed. Follow these steps and you won't be "pumping" oil into the intake system of your 928. Follow these steps and you won't have to think you might have solved the problem, but know that these pieces have been tested and actually do solve the problem.
That is what this thread is about.
I do suggest it sometimes and I did start modifying stock parts for other more common engines. I did not do it for the 928 nor the 944 nor the 924. Wait, I did tell people they would need to relieve the inside of their pan in some cases.
I also go WAY out of my way to accommodate other manufacturers parts. Example, DCR pickups for the SRT4 with no screening. Huge public debate with him over that. I finally said that I had spoken my peace and made a baffle to accomodate it. His strap kits (and others) as well.
#120
Greg, to follow up on my last post and address what you wrote here. My solution for the 928 was completely bolt in using original fasteners etc. I agonized over whether I should design parts that required people to actually drill into their parts. (I am referencing late sumps versus early sumps then the GTS.) It would be easy for me to come in and require people to drill here, weld there and on and on.
I do suggest it sometimes and I did start modifying stock parts for other more common engines. I did not do it for the 928 nor the 944 nor the 924. Wait, I did tell people they would need to relieve the inside of their pan in some cases.
I also go WAY out of my way to accommodate other manufacturers parts. Example, DCR pickups for the SRT4 with no screening. Huge public debate with him over that. I finally said that I had spoken my peace and made a baffle to accomodate it. His strap kits (and others) as well.
I do suggest it sometimes and I did start modifying stock parts for other more common engines. I did not do it for the 928 nor the 944 nor the 924. Wait, I did tell people they would need to relieve the inside of their pan in some cases.
I also go WAY out of my way to accommodate other manufacturers parts. Example, DCR pickups for the SRT4 with no screening. Huge public debate with him over that. I finally said that I had spoken my peace and made a baffle to accomodate it. His strap kits (and others) as well.
Are you saying that your "solution" for the 928 engine is your scraper and windage tray and this will eliminate all the oiling problems in the 928 engine?