Oil pan baffle archeological find: totally useless or answer to acillies heel?
02-21-2010, 05:58 PM
#31
Race Director
Primary? I fault the slight slope of the pan as being worse. Or is it the closeness of the pan to the crank? In an case, the pan design is bad and wasn't fixed. Hard to lower the sump or pan. Could have raised the engine and flattened the intake, but they didn't.
I'd like to see the back of the Porsche windage piece. What'd be cool is to have vanes that direct the swirling air forwards and along the floor of the pan.
I'd like to see the back of the Porsche windage piece. What'd be cool is to have vanes that direct the swirling air forwards and along the floor of the pan.
But for the street, the pan is fine.....the high # of 928's with seriously high mileage proves that....its just the track driven 928's expose the weakness....even the ORR cars don't have problems....they spend lots of time at high RPM, but with relatively low lateral G loads.....
02-21-2010, 06:03 PM
#32
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Aryan,
Were you able to ask the guy that bought it what his plans for it are, is he
going to make a coffee table decoration out of it or is he going to test it &
develop it ? Would he be willing to send it to the US so some of the experts
over here could see it and evaluate it. This piece is the rarest 928 archeological
find to come along in ages, it may be a totally usesless part or it might be the
answer to one of biggest acillies our motors have. I just hope he doesn't stuff
it away like the factory has been doing to us all these years, I hope he shares
the knowledge, good or bad..
Were you able to ask the guy that bought it what his plans for it are, is he
going to make a coffee table decoration out of it or is he going to test it &
develop it ? Would he be willing to send it to the US so some of the experts
over here could see it and evaluate it. This piece is the rarest 928 archeological
find to come along in ages, it may be a totally usesless part or it might be the
answer to one of biggest acillies our motors have. I just hope he doesn't stuff
it away like the factory has been doing to us all these years, I hope he shares
the knowledge, good or bad..
02-21-2010, 06:24 PM
#33
Nordschleife Master
If they got as far as making a mold and didn't produce it then it may have failed in testing. That'd be a few bucks each to make after something like $20K to design and make the first one.
I was hoping that Kevin J. would give a technical opinion.
That "GTS" baffle is near worthless. Since it doesn't seal across the back it doesn't hold the oil in the pan. It does shield half of the surface from blowing air but that's not the problem. (IMO) It is very cheap to design, make and install. Had to be a factor in going with the "07" approach instead of "06."
I was hoping that Kevin J. would give a technical opinion.
That "GTS" baffle is near worthless. Since it doesn't seal across the back it doesn't hold the oil in the pan. It does shield half of the surface from blowing air but that's not the problem. (IMO) It is very cheap to design, make and install. Had to be a factor in going with the "07" approach instead of "06."
I'd guess its most likely a marine part number, or possibly Porsche Motorsports Dept. stuff before the decision to can the 928 came along.
Long shot, I know, but does anyone have a photo of the inside of a Marine oil pan? Wondering if there's a boss for the bolt that went directly into the pan.
Oh well, interesting stuff to ponder
02-21-2010, 06:51 PM
#34
Aryan,
Thanks, I didn't know it was still available.
I looked at that site and used the translator, he
said that it was used for a short "Test drive" now
in my mind that says it is in a car. If he had said it was
used for a short "Sea trial" one would assume it was a
boat part.
Thanks..
Thanks, I didn't know it was still available.
I looked at that site and used the translator, he
said that it was used for a short "Test drive" now
in my mind that says it is in a car. If he had said it was
used for a short "Sea trial" one would assume it was a
boat part.
Thanks..
02-21-2010, 06:55 PM
#35
Nordschleife Master
But for the street, the pan is fine.....the high # of 928's with seriously high mileage proves that....its just the track driven 928's expose the weakness....even the ORR cars don't have problems....they spend lots of time at high RPM, but with relatively low lateral G loads.....
The solution is simple: get liquid oil to the pickup.
(There is no emoticon, or set of emoticons, to adequately express my feelings on that statement.)
02-21-2010, 08:03 PM
#36
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My wild guess is that this is one of several in engines set aside for back door factory support:
If they opened up the sump -- no problem, it had a factory part number. Right?
The underlying problem remained but this part probably reduced the severity.
THE MAX MORITZ SEMI WORKS 928 GTR
... although the engine was no more than fine-tuned after chosen from a set of high power output specimen in Weissach. In the last race of the season at Hockenheim a crank-bearing ran dry. As the car was supposed to race in 1995 as well, she was made ready to continue her successful competition in the 1995 season. A fresh engine was installed, selected from the same lot of high output engines and tuned as before. But in 1995 Porsche´s 928-production came to an end and the car consequently was no more raced in the new season.
... although the engine was no more than fine-tuned after chosen from a set of high power output specimen in Weissach. In the last race of the season at Hockenheim a crank-bearing ran dry. As the car was supposed to race in 1995 as well, she was made ready to continue her successful competition in the 1995 season. A fresh engine was installed, selected from the same lot of high output engines and tuned as before. But in 1995 Porsche´s 928-production came to an end and the car consequently was no more raced in the new season.
The underlying problem remained but this part probably reduced the severity.
02-22-2010, 12:05 AM
#37
Rennlist Member
I have no scraper, oil pan changes etc. always 5 bar+ oil pressure except for turn 2 at thunderhill, where its 4.5bar on a 90 degree day with oil temps of 250F.
Point is, the acceleration of the car in 3-4th gears is not enough to counteract the force of gravity for the oil coming off the back half of the engine. if the oil was not able to return to the sump, then you would be totally dry in a few seconds. even if the acceleration was 1G, the slope equiv would be at a 45 degree angle.
Again, we are talking 106 race days, 1:59s at thunderhill, 1:47-8s at Sears, and 1:37-8s at laguna year after year after year. No issues. Its not open road racing, full throttle , no real braking, its on the race track.
Point is, the acceleration of the car in 3-4th gears is not enough to counteract the force of gravity for the oil coming off the back half of the engine. if the oil was not able to return to the sump, then you would be totally dry in a few seconds. even if the acceleration was 1G, the slope equiv would be at a 45 degree angle.
Again, we are talking 106 race days, 1:59s at thunderhill, 1:47-8s at Sears, and 1:37-8s at laguna year after year after year. No issues. Its not open road racing, full throttle , no real braking, its on the race track.
02-22-2010, 12:51 AM
#38
Nordschleife Master
Point is, the acceleration of the car in 3-4th gears is not enough to counteract the force of gravity for the oil coming off the back half of the engine. if the oil was not able to return to the sump, then you would be totally dry in a few seconds. even if the acceleration was 1G, the slope equiv would be at a 45 degree angle.
02-22-2010, 01:57 AM
#39
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Whats interesting is it appears to my laymans eyes that this baffle was designed for a broader solution than the GTS baffle which has the superceding part number.
By broader solution, I mean actually attempting to condense the windage by separating/scraping it from the rotating crank, unlike the GTS one which just aims to keep more oil around the pickup and prevent the oil wave moving back along the pan due to acceleration.
Given the complexity difference, I have to wonder whether the later design was created as a cheaper solution, rather than as a more effective one?
Also - looking at it, I find myself wondering whether it may even work in addition to the GTS baffle? Looks like a fair bit of clearance under it, and as though there wouldn't be interference around the pickup.
Pic of the GTS baffle in my '89's sump attached to see what I mean.
Interesting that this implies Porsche must have been working on a crank scraper for the 928 sometime before the 1992 introduction of the GTS.
By broader solution, I mean actually attempting to condense the windage by separating/scraping it from the rotating crank, unlike the GTS one which just aims to keep more oil around the pickup and prevent the oil wave moving back along the pan due to acceleration.
Given the complexity difference, I have to wonder whether the later design was created as a cheaper solution, rather than as a more effective one?
Also - looking at it, I find myself wondering whether it may even work in addition to the GTS baffle? Looks like a fair bit of clearance under it, and as though there wouldn't be interference around the pickup.
Pic of the GTS baffle in my '89's sump attached to see what I mean.
Interesting that this implies Porsche must have been working on a crank scraper for the 928 sometime before the 1992 introduction of the GTS.
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Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
greg brown
714 879 9072
GregBBRD@aol.com
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
02-22-2010, 02:08 AM
#40
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Absolutely pulls more g's than any 928 I've ever sat in.
The pan is incredible.
02-22-2010, 10:27 AM
#42
Nordschleife Master
02-22-2010, 11:07 AM
#43
Rennlist Member
all positive Gs because its a v hull? or is it a flat bottom like a tournament boat. with those, yes the Gs are tremendous,but only for a second or two .
mk
mk
02-22-2010, 11:10 AM
#44
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Just a quick reply...
I think the part was developed well after the GTS sump baffle. I think the part number was deliberately contrived by their Skunk Works in order to fit in with "we just had these selected high output engines sitting around waiting for whatever." Probably some of the water cooling engineers wanted to finally kick the air cooling engineers butts or some such.
The casting gates in the floor of the stock pan are markedly smaller than those in and around the sump well which were designed to be tapped for M6 bolts.
It was all about the money/cost which is why this was probably pulled off with funding from a different part of the budget -- very late at night -- in the dark. Whatever design/cost review they had for production parts would have been crawling all over them to modify the pan casting for proper fastener support or -- rather -- to forget about modifying the pan casting. In your dreams, Otto. Good Lord, they would have extended the flange by 2mm if cost was not an issue instead of making funky thick gaskets. They would have stuck with the original trick sump components if cost was not an issue.
[muffled scream]
I think the part was developed well after the GTS sump baffle. I think the part number was deliberately contrived by their Skunk Works in order to fit in with "we just had these selected high output engines sitting around waiting for whatever." Probably some of the water cooling engineers wanted to finally kick the air cooling engineers butts or some such.
The casting gates in the floor of the stock pan are markedly smaller than those in and around the sump well which were designed to be tapped for M6 bolts.
It was all about the money/cost which is why this was probably pulled off with funding from a different part of the budget -- very late at night -- in the dark. Whatever design/cost review they had for production parts would have been crawling all over them to modify the pan casting for proper fastener support or -- rather -- to forget about modifying the pan casting. In your dreams, Otto. Good Lord, they would have extended the flange by 2mm if cost was not an issue instead of making funky thick gaskets. They would have stuck with the original trick sump components if cost was not an issue.
[muffled scream]
02-22-2010, 11:21 AM
#45
Rennlist Member
The point is, the slope of the pan is fine. I dont have the angle handy, but the G loading in straight line acceleration of you're car is around .6G in first, .4Gs in 2nd, .3Gs in 3rd, .2Gs in 4th and less than .2Gs in 5th. The math would say that the oil falls back in all gears but 1st, and the max time you can spend there is a little over a second.
The math also says that if you were right, my stints in 3rd gear for over 4 seconds would have all the oil from the back 2/3s of the engine piling up and not making it to the pan, thus starving the engine sump dry, epecially in 4th where you can go over 10-15 seconds , before your "5th",where that would be the only gear where the oil gets trapped at the rear of the pan.
My main point is for hard core racing, the engine design is just fine as proven by Joe Fan, (only an accusump), Scot, and myself with over 200 combined race days on the 928 engine with NO mods what so ever. In fact, Scot doesent even have the stock oil cooler.. We have a lot more laps running a heck of a lot faster than you or Brian in the widow, or Lemons car. Those laps are as fast as I run on cool down laps.
The math also says that if you were right, my stints in 3rd gear for over 4 seconds would have all the oil from the back 2/3s of the engine piling up and not making it to the pan, thus starving the engine sump dry, epecially in 4th where you can go over 10-15 seconds , before your "5th",where that would be the only gear where the oil gets trapped at the rear of the pan.
My main point is for hard core racing, the engine design is just fine as proven by Joe Fan, (only an accusump), Scot, and myself with over 200 combined race days on the 928 engine with NO mods what so ever. In fact, Scot doesent even have the stock oil cooler.
. We have a lot more laps running a heck of a lot faster than you or Brian in the widow, or Lemons car. Those laps are as fast as I run on cool down laps.