Crank #2 & 6 oiling problem???
04-25-2003, 09:05 AM
#16
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Ed,
Wasn't part of the opinion on your "loss" low oil level?
I figure two things:
1. Drill it like a chevy
2. Keep the oil pickup submerged in oil. (Or d-s or a-s)
Jim, how does MA keep the oil pressure up in those high g situations?
Wasn't part of the opinion on your "loss" low oil level?
I figure two things:
1. Drill it like a chevy
2. Keep the oil pickup submerged in oil. (Or d-s or a-s)
Jim, how does MA keep the oil pressure up in those high g situations?
04-25-2003, 09:13 AM
#17
Rennlist Member
There are two issues with 2.6 oiling failures.....oil galley flow and oil pickup starvation.....unless you are revving over 7K, the later is the only one that applies to the common 2.6 failure.
You can drill your cranks any way you like, but it will not solve the under 7000 rpm 2/6 oiling problem. We thought that this was a partial solution long ago, but further research indicated that there were other forces at play...no pun intended.
Only an accusump, properly installed will do the trick. Porsche AG recognized our solution years ago and bought our Racing Accusump kits for their racing customers.
We identified the problems and developed the solutions long ago, and have proven it to work time and time again on sub 7K rpm racers with non-drilled cranks!
Marc
DEVEK
You can drill your cranks any way you like, but it will not solve the under 7000 rpm 2/6 oiling problem. We thought that this was a partial solution long ago, but further research indicated that there were other forces at play...no pun intended.
Only an accusump, properly installed will do the trick. Porsche AG recognized our solution years ago and bought our Racing Accusump kits for their racing customers.
We identified the problems and developed the solutions long ago, and have proven it to work time and time again on sub 7K rpm racers with non-drilled cranks!
Marc
DEVEK
04-25-2003, 09:17 AM
#18
Rennlist Member
OR you can use a dry sump ala the late Bob DeVore who designed and installed the first one in 1988, when other were blowing up 300 hp euros engine, Bob was building professional level racecars...Bob figured out how to use the stock oil pump as the feed and just add a scavenging pump!
Bob DeVore is the DEV in DEVEK...
Marc
Bob DeVore is the DEV in DEVEK...
Marc
04-25-2003, 09:28 AM
#19
Burning Brakes
I just dred reading stories like this 
Especially when this afternoon will be my first time on a racetrack with my 928 <img border="0" title="" alt="[Eek!]" src="eek.gif" />
Correct me if I am wrong but don't the autobahns have quite a few curves built into them? It certainly wouldn't be a 1g corner but unlike arrow straight US highways, I think the bahns are a little more twisty. At 150 mph even a mild curve could cause the oil to climb up the side of the pan. Just a possibility.
According to DEVEK, the solution accepted by the factory was the Accusump system. I do agree that there is still a big question in my mind as to whether or not it is a true "solution".
After a whole winter of research into this potential failure point I have made the following changes. I installed a 3qt Accusump system in my car. I put it behind the front bumper so the path to the crank is as short as possible. I am running 20-50 Amsoil in the pan. It is said to have good anit-foaming properties. Churned up oil (aerated) seems to be an issue based on Louis Otts testing. Amsoil also claims the best anti wear properties out there. I will also refrain from running high rpms in the corners. Others seem to have been fairly successful with one or the other of these methods, I am combining the two in hope that my engine continues to live a long healthy life even with 4-5 high speed track events per year.
If I am wrong, can I contact you for one of those cheap GT engines???
Especially when this afternoon will be my first time on a racetrack with my 928 <img border="0" title="" alt="[Eek!]" src="eek.gif" /> Correct me if I am wrong but don't the autobahns have quite a few curves built into them? It certainly wouldn't be a 1g corner but unlike arrow straight US highways, I think the bahns are a little more twisty. At 150 mph even a mild curve could cause the oil to climb up the side of the pan. Just a possibility.
According to DEVEK, the solution accepted by the factory was the Accusump system. I do agree that there is still a big question in my mind as to whether or not it is a true "solution".
After a whole winter of research into this potential failure point I have made the following changes. I installed a 3qt Accusump system in my car. I put it behind the front bumper so the path to the crank is as short as possible. I am running 20-50 Amsoil in the pan. It is said to have good anit-foaming properties. Churned up oil (aerated) seems to be an issue based on Louis Otts testing. Amsoil also claims the best anti wear properties out there. I will also refrain from running high rpms in the corners. Others seem to have been fairly successful with one or the other of these methods, I am combining the two in hope that my engine continues to live a long healthy life even with 4-5 high speed track events per year.
If I am wrong, can I contact you for one of those cheap GT engines???
04-25-2003, 03:03 PM
#20
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Brent 89-GT:
<strong>I installed a 3qt Accusump system in my car. I put it behind the front bumper so the path to the crank is as short as possible. I am running 20-50 Amsoil in the pan. It is said to have good anit-foaming properties. Churned up oil (aerated) seems to be an issue based on Louis Otts testing. Amsoil also claims the best anti wear properties out there. I will also refrain from running high rpms in the corners.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That's pretty much all you can do.
I've done about 30 track days with my car and probably another 30 were done by the previous owner. It has the Devek racing Accusump kit. I've been using Mobil-1 15w50 and am switching to Amsoil. I try to use 6k shift points when I can, but sometimes in the heat of battle that goes out the window. I've never hit the rev limiter though. I have been only using street compound tires but it's still enough to generate 1.0 g pretty consistently. The previous owner ran a few days on r-compounds.
When people see the Accusump in the back, they always have questions. Judging from these conversations, lots of other production cars have the same problems with oil starvation.
<strong>I installed a 3qt Accusump system in my car. I put it behind the front bumper so the path to the crank is as short as possible. I am running 20-50 Amsoil in the pan. It is said to have good anit-foaming properties. Churned up oil (aerated) seems to be an issue based on Louis Otts testing. Amsoil also claims the best anti wear properties out there. I will also refrain from running high rpms in the corners.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That's pretty much all you can do.
I've done about 30 track days with my car and probably another 30 were done by the previous owner. It has the Devek racing Accusump kit. I've been using Mobil-1 15w50 and am switching to Amsoil. I try to use 6k shift points when I can, but sometimes in the heat of battle that goes out the window. I've never hit the rev limiter though. I have been only using street compound tires but it's still enough to generate 1.0 g pretty consistently. The previous owner ran a few days on r-compounds.
When people see the Accusump in the back, they always have questions. Judging from these conversations, lots of other production cars have the same problems with oil starvation.
04-28-2003, 02:36 AM
#21
Burning Brakes
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Hi,
Nobby Shark
In an earlier post I asked a couple of questions of you - could you answer please?
a) what oil were you using ( brand, viscosity etc. )?
b) had the vehicle been using oil ?, and,
c) was there much oil left in the sump?
Other points of interest,
d) was the engine running hot ( where had the gauge been reading )?
e) what was the oil pressure during the trip ?
I for one would be interested in your replies
Regards
Nobby Shark
In an earlier post I asked a couple of questions of you - could you answer please?
a) what oil were you using ( brand, viscosity etc. )?
b) had the vehicle been using oil ?, and,
c) was there much oil left in the sump?
Other points of interest,
d) was the engine running hot ( where had the gauge been reading )?
e) what was the oil pressure during the trip ?
I for one would be interested in your replies
Regards
04-28-2003, 07:14 AM
#22
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Doug Hillary:
<strong>Hi,
Nobby Shark
In an earlier post I asked a couple of questions of you - could you answer please?
a) what oil were you using ( brand, viscosity etc. )?
b) had the vehicle been using oil ?, and,
c) was there much oil left in the sump?
Other points of interest,
d) was the engine running hot ( where had the gauge been reading )?
e) what was the oil pressure during the trip ?
I for one would be interested in your replies
Regards</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">S
<strong>Hi,
Nobby Shark
In an earlier post I asked a couple of questions of you - could you answer please?
a) what oil were you using ( brand, viscosity etc. )?
b) had the vehicle been using oil ?, and,
c) was there much oil left in the sump?
Other points of interest,
d) was the engine running hot ( where had the gauge been reading )?
e) what was the oil pressure during the trip ?
I for one would be interested in your replies
Regards</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">S
04-28-2003, 07:40 AM
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Sorry about that,,, shaky hands I guess. Probably due to the cost of a replacement GT engine which I collected on Saturday. Two days and a few grand lighter. Sweet engine though.
So many replies, a popular and concerning topic. I'd just like to say a quick thank you to Mike Schmidt who wrote to me about this subject in detail with pictures of his baffle etc. Top guy.
About the failure,,,, the oil was a little low I guess, mobil 1, straight line few curves, running fine, not hot, very loud bang, lots of vibration and a cold sweat. I will post pictures of the rod and journal later as there is some interest. What is curious is that the block and 1 to 4 cylinder head had been replaced before,,, the castings were dated 91 not 90 like the rest of the engine. Also curious was the fact that the other crank journals were minty,,,.
I guess the damage could have been done before, or started before that trip.
I'm going to strip and rebuild the new engine which has 95k on it. I have some questions about exactly how far to rebuild and what to replace and I will start another thread if I can't find the answers but here is my main one. The bores and crank are sweet on the new engine and now that it is apart I'm going to put it back as best I can so it will eat another 100k. Should I re ring it or not ?? I'm going to renew the bearings on the crank anyway,,, but what about the rings and should I do the little ends as well??
Any thoughts
Cheers.
So many replies, a popular and concerning topic. I'd just like to say a quick thank you to Mike Schmidt who wrote to me about this subject in detail with pictures of his baffle etc. Top guy.
About the failure,,,, the oil was a little low I guess, mobil 1, straight line few curves, running fine, not hot, very loud bang, lots of vibration and a cold sweat. I will post pictures of the rod and journal later as there is some interest. What is curious is that the block and 1 to 4 cylinder head had been replaced before,,, the castings were dated 91 not 90 like the rest of the engine. Also curious was the fact that the other crank journals were minty,,,.
I guess the damage could have been done before, or started before that trip.
I'm going to strip and rebuild the new engine which has 95k on it. I have some questions about exactly how far to rebuild and what to replace and I will start another thread if I can't find the answers but here is my main one. The bores and crank are sweet on the new engine and now that it is apart I'm going to put it back as best I can so it will eat another 100k. Should I re ring it or not ?? I'm going to renew the bearings on the crank anyway,,, but what about the rings and should I do the little ends as well??
Any thoughts
Cheers.
04-28-2003, 09:49 AM
#24
Burning Brakes
If you're taking the new engine apart, you might as well put new rings in it. I would also replace the cam chains and their adjustment pads. While the heads are off, check the valves, valve guides, and seals.
Even though the main journals look good, I'd replace them too. Might as well make it as new an engine as you can while you're that far itno it. YMMV.
Even though the main journals look good, I'd replace them too. Might as well make it as new an engine as you can while you're that far itno it. YMMV.
04-28-2003, 10:36 AM
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Ed,
I agree totally, but what about this new rings in old bores issue. Do they bed in well?? I have seen people on here talking about leaving them alone. I do not intend to touch the bores at all as they are sweet, not a single mark with 95k on the clock. Like you I feel I owe it to myself to make the engine as new as possible while it is on the bench but this issue worries me,,,,, (partly something to do with the other engine on the bench and what this exercise is costing me, having said this I want it right).
Cheers.
I agree totally, but what about this new rings in old bores issue. Do they bed in well?? I have seen people on here talking about leaving them alone. I do not intend to touch the bores at all as they are sweet, not a single mark with 95k on the clock. Like you I feel I owe it to myself to make the engine as new as possible while it is on the bench but this issue worries me,,,,, (partly something to do with the other engine on the bench and what this exercise is costing me, having said this I want it right).
Cheers.
04-28-2003, 10:59 AM
#26
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There's been quite a bit of discussion of the re-ringing issue. I'd say do it. Fresh anything is better than tired. Marc @ Devek has seen tons of fresh rings in old bores and says they seal fine.
04-28-2003, 12:21 PM
#27
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"> fresh rings in old bores </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Works well on my track car.
04-28-2003, 01:00 PM
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I will go for new rings and sleep easier tonight,,,,, that dream where the new engine throws the #2 rod during the running in period may start to go away now!!!
04-28-2003, 06:12 PM
#29
Thanks for replying to my private message. I think I will look at my options as to my personal settings on the Rennlist as direct email is better I think. I have heard of the breakers you mentioned.
What are you going to do with your old blown motor? It's still worth something. Once again thanks for your response.
Greg
What are you going to do with your old blown motor? It's still worth something. Once again thanks for your response.
Greg
04-30-2009, 08:07 AM
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There are two issues with 2.6 oiling failures.....oil galley flow and oil pickup starvation.....unless you are revving over 7K, the later is the only one that applies to the common 2.6 failure.
You can drill your cranks any way you like, but it will not solve the under 7000 rpm 2/6 oiling problem. We thought that this was a partial solution long ago, but further research indicated that there were other forces at play...no pun intended.
Only an accusump, properly installed will do the trick. Porsche AG recognized our solution years ago and bought our Racing Accusump kits for their racing customers.
We identified the problems and developed the solutions long ago, and have proven it to work time and time again on sub 7K rpm racers with non-drilled cranks!
Marc
DEVEK
You can drill your cranks any way you like, but it will not solve the under 7000 rpm 2/6 oiling problem. We thought that this was a partial solution long ago, but further research indicated that there were other forces at play...no pun intended.
Only an accusump, properly installed will do the trick. Porsche AG recognized our solution years ago and bought our Racing Accusump kits for their racing customers.
We identified the problems and developed the solutions long ago, and have proven it to work time and time again on sub 7K rpm racers with non-drilled cranks!
Marc
DEVEK
Pictures?
My 944S has spun #2 twice allready. I have Moroso 3 liter Accusump and now I have to install it.
How is oil level measured with accusump?