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Overfilling oil for track use?

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Old 05-19-2010 | 02:09 PM
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but still faster than you ... geez
Old 05-19-2010 | 04:24 PM
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Originally Posted by gt37vgt
but still faster than you ... geez
What can I say? I like fast women...
Old 05-19-2010 | 05:31 PM
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Chris -- thanks for the info, very interesting.

I just had a quick question re: your comment about the 90* bends in the oil passages and Porsche never intending to race the motor:

In the racing 944 world, is anything done to the oil system of the car to help with this issue (besides the obvious dry sump)? Specifically, these 90* bends? Having never built a pure race motor for a 944, I've got no experience with this.
Old 05-19-2010 | 06:18 PM
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Originally Posted by ausgeflippt951
Chris -- thanks for the info, very interesting.

I just had a quick question re: your comment about the 90* bends in the oil passages and Porsche never intending to race the motor:

In the racing 944 world, is anything done to the oil system of the car to help with this issue (besides the obvious dry sump)? Specifically, these 90* bends? Having never built a pure race motor for a 944, I've got no experience with this.
There is not a lot you can do other than making a crank from billet stock (and that has a lot of issues too – the hardening of the factory crank is very hard to reproduce).

Some folks like to cross drill the crank but that does not help the 90 degree bends. One thought I had a long time ago would be to extrude hone the oil passages in the crank. That would be an interesting project.

I have found that if I don’t over fill the crankcase and the oil temps are kept to a reasonable level the engine will be OK. If you want sustained running over 7k….then you should think about a drysump system!
Old 05-19-2010 | 08:00 PM
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Originally Posted by Chris White
In reality there are four factors that cause the rod bearing problem.
So it sounds like the most cost effective approach is an extra oil cooler and oil pan baffles. Would you agree with that Chris?
Old 05-19-2010 | 08:30 PM
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Originally Posted by ausgeflippt951
Chris -- thanks for the info, very interesting.
+1 Thank you, Chris, wonderful summary and analysis.
Old 05-19-2010 | 08:51 PM
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Originally Posted by JustinL
So it sounds like the most cost effective approach is an extra oil cooler and oil pan baffles. Would you agree with that Chris?
In addition to baffles, would a crank scraper help here, to reduce oil being sucked up into the windage, or is that not a significant factor here?
Old 05-19-2010 | 09:25 PM
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Originally Posted by JustinL
So it sounds like the most cost effective approach is an extra oil cooler and oil pan baffles. Would you agree with that Chris?
‘Yes’ on the oil cooler and ‘maybe not so much’ on the pan baffles. The pan baffles don’t hurt but I don’t think they help with the oil ‘slosh’ .

Originally Posted by Bill N
+1 Thank you, Chris, wonderful summary and analysis.
You guys are welcome! Glad to help out.

Originally Posted by JDS968
In addition to baffles, would a crank scraper help here, to reduce oil being sucked up into the windage, or is that not a significant factor here?
I think the crank scrapers do help and the full windage tray helps even more (but is time consuming to fit!)
Old 05-20-2010 | 02:59 AM
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I spent most of my money on fast cars and fast women the rest i wasted ... drilling the big ends at 90 deg or radial to the crank provides a passage to the big end with a 30 deg bend insted of a 90 also its a pretty reasonable theory that this passage would kind of pump with a bit with crank speed .
I think extrude honing the entire oiling system is a great idea Chris i herd somewhere the extrude honning process was developed initaily for debuting inside complicated hydralic valve body assemblies ..
Old 05-20-2010 | 10:48 AM
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Originally Posted by Chris White
3)There are 90 degree bends in the oil passages in the crank shaft – not a good idea for a performance engine.(Porsche never intended the 944 to be raced and did not do any engine development towards that goal). Hot foamy oil going around 90 degree corners is not a good lubricant..
Doesn't anyone remember the Turbo Cup series in Europe? The Turbo S cars are a result of Porsche's input to the series.

Remember the GT cars?

They may not have won LeMans, but they were racing with engines developed by Porsche for racing.
Old 05-20-2010 | 11:16 AM
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Originally Posted by Willard Bridgham 3
Doesn't anyone remember the Turbo Cup series in Europe? The Turbo S cars are a result of Porsche's input to the series.

Remember the GT cars?

They may not have won LeMans, but they were racing with engines developed by Porsche for racing.
Yes, I am afraid, like you, I am old enough to remember those!

Turbo cup was close to a ‘stock class’ – no internal engine mods allowed. They had to live with the design.

GT cars…dry sumped…problem fixed!

LeMans cars – the early version was a 2.5 liter DOHC motor that was also dry sumped….I don’t know a lot about the later ‘BF Goodrich’ LeMans effort…
Old 05-20-2010 | 11:58 AM
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not all race cars are the ultimate in terms of development there are plenty of one make clases that are very compromised to "try" to keep costs down and sometimes to even make the racing better to watch .
Sometime manufactures even have a massive piles of surplus parts they want to destroy in an entertaining fashion ...ok lets have a race series .



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