2/6 rod bearing flow tests
12-12-2012, 10:24 AM
#91
Electron Wrangler
Lifetime Rennlist
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Lifetime Rennlist
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It does seem like that its a situational thing where you don't need to scavenge all the time - However I think Greg's point is that its not just lateral G, which we already know is a contributing factor but also extended straightaway WOT that need to be sensed, may need a better TPS signal to control for that too - possibly with a small delay. This also helps if you want to keep the air pump - though space for any pump is still very limited
Alan
12-12-2012, 11:14 AM
#92
Rennlist Member
Any pictures of these pumps? - how big are they? In a BMW do they use them similarly one (?) per bank for head scavenge as needed? /other?
It does seem like that its a situational thing where you don't need to scavenge all the time - However I think Greg's point is that its not just lateral G, which we already know is a contributing factor but also extended straightaway WOT that need to be sensed, may need a better TPS signal to control for that too - possibly with a small delay. This also helps if you want to keep the air pump - though space for any pump is still very limited
Alan
It does seem like that its a situational thing where you don't need to scavenge all the time - However I think Greg's point is that its not just lateral G, which we already know is a contributing factor but also extended straightaway WOT that need to be sensed, may need a better TPS signal to control for that too - possibly with a small delay. This also helps if you want to keep the air pump - though space for any pump is still very limited
Alan
12-12-2012, 11:57 AM
#93
Rennlist Member
Join Date: Feb 2011
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The BMW M5 V10 electrical oil pump part no. 11 41 7 834 496. Price $223.17. One pump on each side of the sump.
http://bmwfans.info/parts/catalog/E6...ectr_oil_pump/
Ake
http://bmwfans.info/parts/catalog/E6...ectr_oil_pump/
Ake
12-12-2012, 01:37 PM
#94
Nordschleife Master
I think I "revealed" everything that I found out and my conclusions. I'm naturally not showing all of the internal and external changes that I made to combat the problem. Oil packs into the heads, at high rpms, and then is ejected from the head breathers. At about the same time to oil began to eject from the heads, we had a significant "reduction" in oil pressure....but not enough for the dyno to automatically shut down....we terminated the test. I would anticipate that damage to the bearings would have resulted, if the testing had not been terminated. As it was, the rod bearings had definately "touched" the crankshaft and were replaced. For the "aeration" crowd, it was not frothy, aerated oil, but solid oil. It was "ejected" in spurts of solid oil.
I agree with you that it's smart business practice to keep some parts of your solution secret. However, I am more interested in the exact mechanism by which the problem is created in the first place. Hopefully everyone can discuss that topic freely.
On the off chance you didn't see it, here's the video from the dyno operator of the control screen, 1/28/11, Andy's engine at ~6000 rpm for a minute. Resolution's not the greatest, click the 'gear' in YT and watch it full screen at 480p. You can see the oil pressure gauge (lower left corner) drop from 110 to 90 then fluctuate its way down to 75 at the end. Much yelling about ejected oil ensued immediately thereafter.
The question is whether the pickup sucking air is caused by load or by elapsed time is important one. The operator brings the load down temporarily yet the oil pressure doesn't recover. Because of this, I think it's probably time dependent.
The fluctuations are unlikely to be related to the oil pressure relief valve cycling, as that effect should be the same at 6000 rpm, regardless of the load or elapsed time.
Looks to me like there are two separate issues based on this video. 1) The slow steady drop in oil pressure over 45 seconds or so, presumably due to oil aeration? and 2) what we already know as oil packing in the heads causing an abrupt oil pressure drop towards the end. For 1), I would think that would also be affecting the rod bearings, albeit to a much lesser extent than the oil pickup being uncovered. Thoughts?
The [BMW] pumps are 2/3 of the size of the charcoal canister. BMW uses one per side for each bank of cylinders. The V10 cars have a third pump, which is mounted on the gearbox but there it pumps the oil out and back via the front mounted radiato. The beauty of the electric pump is that you can mount them away from the engine and that they don't run all the time. You don't want a WOT trigger - you want to trigger them via rpm/time/load switch and via g-loads. The fact that the gearbox pump runs continuously gives me confidence in its longevity - plenty of cars on 60k+ miles still on the original pumps...
A reminder: The usual caveat lectors apply doubly to my writings no this topic.
12-12-2012, 01:38 PM
#95
Drifting
I think Greg Brown has a system with his 3 or 4 stage pump system and provents that is for sale and solves the problem very elegantly.....why try to reinvent the wheel????
I dont get it...
I dont get it...
12-12-2012, 01:43 PM
#96
Drifting
top fuel and meth head engines ( my play on words) have been scavenging oil off the heads for eons...and that started when they were using 1\4 mile track....
Now I know the engines are apples and oranges but the top fuel engines are just an example of sudden filling of the heads .....
Now I know the engines are apples and oranges but the top fuel engines are just an example of sudden filling of the heads .....
12-12-2012, 01:43 PM
#97
Nordschleife Master
(I am not developing a competing kit, and have no desire to be in the 928 parts business... It's a ****ty business if there ever was any.)
12-12-2012, 01:45 PM
#98
Nordschleife Master
top fuel and meth head engines ( my play on words) have been scavenging oil off the heads for eons...and that started when they were using 1\4 mile track.... Now I know the engines are apples and oranges but the top fuel engines are just an example of sudden filling of the heads .....
However, can you find me any other 90-degree V engine that actively scavenges the heads and NOT the crankcase when not subjected to acceleration forces?
As far as I understand, the goal in oil drain system design is to make the acceleration forces and pressure forces consistently pointing towards the pick up. That is, you want to scavenge from the point that external loads point to and also make that a low-pressure zone. That's why I think (but do not know) BMW V10 M5 (a car that I once owned) only turns on the head scavenge pump when the acceleration forces (gravity, cornering) start pointing towards the particular head.
By the way, there's nothing here in my writings that should be interpreted as criticism of your car or motor. From all I've read and seen so far, it's a fantastically powerful and reliable engine with a lots of cool parts that I'd also like to have on my engine.
Last edited by ptuomov; 12-12-2012 at 02:10 PM.
12-12-2012, 02:35 PM
#99
Drifting
Sorry Tuomo, I understand what you mean . its would be cool to just put pressure monitors in the important crankcase and head locations while on the dyno and see measured values when things happen....
Hmmmm.....do you have a spare engine....I have the original gts engine from the 93 that we could send to greg and use it as a guinea pig with monitors in it...some one would have to pay for the multple hundreds of dollars per hour those boys charge for the engine dyno time....but I will ship the engine back if someone is willing to set u p the data colleciton....would be really COOL!!!!
Hmmmm.....do you have a spare engine....I have the original gts engine from the 93 that we could send to greg and use it as a guinea pig with monitors in it...some one would have to pay for the multple hundreds of dollars per hour those boys charge for the engine dyno time....but I will ship the engine back if someone is willing to set u p the data colleciton....would be really COOL!!!!
12-12-2012, 03:04 PM
#100
Nordschleife Master
Sorry Tuomo, I understand what you mean . its would be cool to just put pressure monitors in the important crankcase and head locations while on the dyno and see measured values when things happen.... Hmmmm.....do you have a spare engine....I have the original gts engine from the 93 that we could send to greg and use it as a guinea pig with monitors in it...some one would have to pay for the multple hundreds of dollars per hour those boys charge for the engine dyno time....but I will ship the engine back if someone is willing to set u p the data colleciton....would be really COOL!!!!
Cost:
+ Dynapack time is $125 per hour
+ DI-155 is $150
+ Pressure sensors are less than $100
+ Everyone has a notebook computer already $0
= $375.
12-12-2012, 04:24 PM
#101
Rennlist Member
Hello TUomo
I own a Dynapack dyno and can confirm that the aeration that you are all dsicussing here at length is a red herring . If you load up any of the later engines at greater than 5500 rpm you will start destroying the engine bearings , because the sump is instantly pumped dry. Actually I am amazed at how quickly this happens . Now it may be conincidental , but the older vent system that porsche used on the multi valve masks the problem somewhat, as there are less places for the oil to go, other then the manifold , but as this a smaller diameter, it fills and flows into this area. At these higher engine speeds , (which too my mind is not high , as many modern cars exceed 7000 rpm) all the valve cover vents will overflow , and not slowly , it will shoot out of then under pressure , in my particluar case fill the provent and flow out on the floor . None of my hoses is connected to the intake manifold, I am not surprised that these engines blew up as inaddition to the oil in heads problem you also have the engine detonation that oil causes to the conbustion process at high engine speeds. Looking at the BMW sump it appears to have much more volume than the 928 unit , all of the problems mentioned above and that shallow restrictive sump, recipe for problems in a high performance engine , actually I think is mentioned from the engine department when they designed the first one.
For all of you out there who have designs on enjoying the perfomance potential of these engines , Gregs oil system modification should be first on the list , I scratch my head at the chevy conversions that various people under take , the perfomance potential of these 928 engines is better than all the conversions and the engine is at least as strong , and the weight is the same , once the oil issues are solved and thanks to GB , you have an inexpensive solution to the longevity of the car.
I own a Dynapack dyno and can confirm that the aeration that you are all dsicussing here at length is a red herring . If you load up any of the later engines at greater than 5500 rpm you will start destroying the engine bearings , because the sump is instantly pumped dry. Actually I am amazed at how quickly this happens . Now it may be conincidental , but the older vent system that porsche used on the multi valve masks the problem somewhat, as there are less places for the oil to go, other then the manifold , but as this a smaller diameter, it fills and flows into this area. At these higher engine speeds , (which too my mind is not high , as many modern cars exceed 7000 rpm) all the valve cover vents will overflow , and not slowly , it will shoot out of then under pressure , in my particluar case fill the provent and flow out on the floor . None of my hoses is connected to the intake manifold, I am not surprised that these engines blew up as inaddition to the oil in heads problem you also have the engine detonation that oil causes to the conbustion process at high engine speeds. Looking at the BMW sump it appears to have much more volume than the 928 unit , all of the problems mentioned above and that shallow restrictive sump, recipe for problems in a high performance engine , actually I think is mentioned from the engine department when they designed the first one.
For all of you out there who have designs on enjoying the perfomance potential of these engines , Gregs oil system modification should be first on the list , I scratch my head at the chevy conversions that various people under take , the perfomance potential of these 928 engines is better than all the conversions and the engine is at least as strong , and the weight is the same , once the oil issues are solved and thanks to GB , you have an inexpensive solution to the longevity of the car.
12-12-2012, 06:25 PM
#102
Former Vendor
In the past, for some obscure reason that I'm not even really sure of, I felt it important to try and convince every single person that the pieces I design and fabricate really work.
Then, probably when I was beating my head against the wall trying to convince a complete idiot that rod offset was critical, I suddenly realized how futile this was.
Now I simply don't care. If someone wants to design and build another system that does what I've already done...have at it! If someone doubts what I've done works and needs to prove to themselves that my findings and designs are valid...have at it!
In this case, I built two systems. An expensive (and complex) "active" pump system for engines used at the track and used at high rpms. Then I designed and fabricated a less expensive system for the "street guys" that just want to run their cars the way they think they "should" have been designed.
Both completely eliminate the oil that normally gets into the intake system. Both increase crankcase and head ventilation. Both increase the quantity and the rate at which oil can return to the pan. Both reduce the problems with pre-ignition from oil mixing in the fuel. Both significantly reduce oil consumption. Both reduce vehicle emissions. Both allow additional ignition timing to be added (increased performance), after the thick oil deposits are removed from the combustion chambers. Both are completely "closed" crankcase systems.....so that people are not venting their engine to the atmosphere (pre 1957 vehicles).
I really can't think of anything else I could have accomplished, with either system. Consequently, I'm four or five large re-design projects past this stuff....just trying to make "our" 928's better.
Then, probably when I was beating my head against the wall trying to convince a complete idiot that rod offset was critical, I suddenly realized how futile this was.
Now I simply don't care. If someone wants to design and build another system that does what I've already done...have at it! If someone doubts what I've done works and needs to prove to themselves that my findings and designs are valid...have at it!
In this case, I built two systems. An expensive (and complex) "active" pump system for engines used at the track and used at high rpms. Then I designed and fabricated a less expensive system for the "street guys" that just want to run their cars the way they think they "should" have been designed.
Both completely eliminate the oil that normally gets into the intake system. Both increase crankcase and head ventilation. Both increase the quantity and the rate at which oil can return to the pan. Both reduce the problems with pre-ignition from oil mixing in the fuel. Both significantly reduce oil consumption. Both reduce vehicle emissions. Both allow additional ignition timing to be added (increased performance), after the thick oil deposits are removed from the combustion chambers. Both are completely "closed" crankcase systems.....so that people are not venting their engine to the atmosphere (pre 1957 vehicles).
I really can't think of anything else I could have accomplished, with either system. Consequently, I'm four or five large re-design projects past this stuff....just trying to make "our" 928's better.
12-12-2012, 11:19 PM
#103
Didn't you post some info here about the more... "pedestrian" version?
12-12-2012, 11:59 PM
#104
Nordschleife Master
Hello TUomo
I own a Dynapack dyno and can confirm that the aeration that you are all dsicussing here at length is a red herring . If you load up any of the later engines at greater than 5500 rpm you will start destroying the engine bearings , because the sump is instantly pumped dry. Actually I am amazed at how quickly this happens . Now it may be conincidental , but the older vent system that porsche used on the multi valve masks the problem somewhat, as there are less places for the oil to go, other then the manifold , but as this a smaller diameter, it fills and flows into this area. At these higher engine speeds , (which too my mind is not high , as many modern cars exceed 7000 rpm) all the valve cover vents will overflow , and not slowly , it will shoot out of then under pressure , in my particluar case fill the provent and flow out on the floor . None of my hoses is connected to the intake manifold, I am not surprised that these engines blew up as inaddition to the oil in heads problem you also have the engine detonation that oil causes to the conbustion process at high engine speeds. Looking at the BMW sump it appears to have much more volume than the 928 unit , all of the problems mentioned above and that shallow restrictive sump, recipe for problems in a high performance engine , actually I think is mentioned from the engine department when they designed the first one.
For all of you out there who have designs on enjoying the perfomance potential of these engines , Gregs oil system modification should be first on the list , I scratch my head at the chevy conversions that various people under take , the perfomance potential of these 928 engines is better than all the conversions and the engine is at least as strong , and the weight is the same , once the oil issues are solved and thanks to GB , you have an inexpensive solution to the longevity of the car.
I own a Dynapack dyno and can confirm that the aeration that you are all dsicussing here at length is a red herring . If you load up any of the later engines at greater than 5500 rpm you will start destroying the engine bearings , because the sump is instantly pumped dry. Actually I am amazed at how quickly this happens . Now it may be conincidental , but the older vent system that porsche used on the multi valve masks the problem somewhat, as there are less places for the oil to go, other then the manifold , but as this a smaller diameter, it fills and flows into this area. At these higher engine speeds , (which too my mind is not high , as many modern cars exceed 7000 rpm) all the valve cover vents will overflow , and not slowly , it will shoot out of then under pressure , in my particluar case fill the provent and flow out on the floor . None of my hoses is connected to the intake manifold, I am not surprised that these engines blew up as inaddition to the oil in heads problem you also have the engine detonation that oil causes to the conbustion process at high engine speeds. Looking at the BMW sump it appears to have much more volume than the 928 unit , all of the problems mentioned above and that shallow restrictive sump, recipe for problems in a high performance engine , actually I think is mentioned from the engine department when they designed the first one.
For all of you out there who have designs on enjoying the perfomance potential of these engines , Gregs oil system modification should be first on the list , I scratch my head at the chevy conversions that various people under take , the perfomance potential of these 928 engines is better than all the conversions and the engine is at least as strong , and the weight is the same , once the oil issues are solved and thanks to GB , you have an inexpensive solution to the longevity of the car.
In the past, for some obscure reason that I'm not even really sure of, I felt it important to try and convince every single person that the pieces I design and fabricate really work.
Then, probably when I was beating my head against the wall trying to convince a complete idiot that rod offset was critical, I suddenly realized how futile this was.
Now I simply don't care. If someone wants to design and build another system that does what I've already done...have at it! If someone doubts what I've done works and needs to prove to themselves that my findings and designs are valid...have at it!
In this case, I built two systems. An expensive (and complex) "active" pump system for engines used at the track and used at high rpms. Then I designed and fabricated a less expensive system for the "street guys" that just want to run their cars the way they think they "should" have been designed.
Both completely eliminate the oil that normally gets into the intake system. Both increase crankcase and head ventilation. Both increase the quantity and the rate at which oil can return to the pan. Both reduce the problems with pre-ignition from oil mixing in the fuel. Both significantly reduce oil consumption. Both reduce vehicle emissions. Both allow additional ignition timing to be added (increased performance), after the thick oil deposits are removed from the combustion chambers. Both are completely "closed" crankcase systems.....so that people are not venting their engine to the atmosphere (pre 1957 vehicles).
I really can't think of anything else I could have accomplished, with either system. Consequently, I'm four or five large re-design projects past this stuff....just trying to make "our" 928's better.
Then, probably when I was beating my head against the wall trying to convince a complete idiot that rod offset was critical, I suddenly realized how futile this was.
Now I simply don't care. If someone wants to design and build another system that does what I've already done...have at it! If someone doubts what I've done works and needs to prove to themselves that my findings and designs are valid...have at it!
In this case, I built two systems. An expensive (and complex) "active" pump system for engines used at the track and used at high rpms. Then I designed and fabricated a less expensive system for the "street guys" that just want to run their cars the way they think they "should" have been designed.
Both completely eliminate the oil that normally gets into the intake system. Both increase crankcase and head ventilation. Both increase the quantity and the rate at which oil can return to the pan. Both reduce the problems with pre-ignition from oil mixing in the fuel. Both significantly reduce oil consumption. Both reduce vehicle emissions. Both allow additional ignition timing to be added (increased performance), after the thick oil deposits are removed from the combustion chambers. Both are completely "closed" crankcase systems.....so that people are not venting their engine to the atmosphere (pre 1957 vehicles).
I really can't think of anything else I could have accomplished, with either system. Consequently, I'm four or five large re-design projects past this stuff....just trying to make "our" 928's better.
12-13-2012, 12:12 AM
#105
Nordschleife Master