93 928 gts oil consumption
03-12-2014 | 02:28 PM
#76
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From: Helsinki, Finland
Anyway: as we will soon do the OPG replacement maintenance, we can have a look at them. However: look but no touching let alone taking anything apart, because "when it works don't fix it"...
03-12-2014 | 02:35 PM
#77
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Sounds like Erkka's a bit like the Finnish version of Brendan... comes apart quick! - goes back together... much later & slowly
Alan
03-12-2014 | 02:53 PM
#78
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It is super highly unlikely that Porsche would bother to introduce 2R rods on all late MY 94 and all MY 95 engines and not change the pistons for US and ROW cars. That is not how things are done. I would actually say, it is nigh on impossible. All early GTSs don't have the holes drilled and the actual piston is different. The late GTS pistons look a lot more like a 968 piston...
I've not seen a single piston from a GTS engine that was drilled, from the factory, so I had no idea any of them were that way.
03-12-2014 | 04:42 PM
#80
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My understanding is that they replaced the engine with one exactly the same. I've had at least one of these "replacement engines" apart....no holes.
03-12-2014 | 05:21 PM
#81
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03-12-2014 | 05:26 PM
#82
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I never use the sunroof anyway.
03-12-2014 | 10:57 PM
#86
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03-12-2014 | 11:14 PM
#87
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Here's why I think it's virtually impossible for the wrist pint not to get oiled well
Take a look at the below picture. It's an S4 crankcase, not GTS, but the same point about the geometry applies. Yes, it's a zoom up of another picture so picture quality is not great.
The oil sprays out of the three points on the rod journal. From between the rod big ends and from two spots on the outsides of the rod big ends. Those oil sprays form a disc when the crankshaft rotates at high speed. The oil spray disc hits exactly on the exposed section of the wrist pin on both sides of the rod small ends. There's in my opinion _no way_ that with that much bare pin exposure at that location the pin isn't properly splash oiled.
Furthermore, pulling vaccuum in the crankcase will cause the disc to be less disrupted and thinner, leading to an even large fraction of the oil spray hitting the wrist pin exactly.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
The oil sprays out of the three points on the rod journal. From between the rod big ends and from two spots on the outsides of the rod big ends. Those oil sprays form a disc when the crankshaft rotates at high speed. The oil spray disc hits exactly on the exposed section of the wrist pin on both sides of the rod small ends. There's in my opinion _no way_ that with that much bare pin exposure at that location the pin isn't properly splash oiled.
Furthermore, pulling vaccuum in the crankcase will cause the disc to be less disrupted and thinner, leading to an even large fraction of the oil spray hitting the wrist pin exactly.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
03-13-2014 | 12:59 AM
#88
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From: West Vancouver, Canada
Take a look at the below picture. It's an S4 crankcase, not GTS, but the same point about the geometry applies. Yes, it's a zoom up of another picture so picture quality is not great.
Attachment 814624
The oil sprays out of the three points on the rod journal. From between the rod big ends and from two spots on the outsides of the rod big ends. Those oil sprays form a disc when the crankshaft rotates at high speed. The oil spray disc hits exactly on the exposed section of the wrist pin on both sides of the rod small ends. There's in my opinion _no way_ that with that much bare pin exposure at that location the pin isn't properly splash oiled.
Furthermore, pulling vaccuum in the crankcase will cause the disc to be less disrupted and thinner, leading to an even large fraction of the oil spray hitting the wrist pin exactly.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
Attachment 814624
The oil sprays out of the three points on the rod journal. From between the rod big ends and from two spots on the outsides of the rod big ends. Those oil sprays form a disc when the crankshaft rotates at high speed. The oil spray disc hits exactly on the exposed section of the wrist pin on both sides of the rod small ends. There's in my opinion _no way_ that with that much bare pin exposure at that location the pin isn't properly splash oiled.
Furthermore, pulling vaccuum in the crankcase will cause the disc to be less disrupted and thinner, leading to an even large fraction of the oil spray hitting the wrist pin exactly.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
All the best,
Joe
03-13-2014 | 02:00 AM
#89
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From: Abbotsford B.C.
Tuomo,
An additional point, the clearance between the big ends is much tighter than is thought to be "good" these days too. All stokers open up this gap a fair bit. The vacuum will actually make the disc a little stronger too, increasing oiling to the wrist pin.
But given this with no one else ever seeing bluing, or wear to the wrist pins I really would love to see the "fact" Greg is stating with pictures to back it up.
I'd love him to post the pictures showing this like he showed how the factory fuel rails had bigger tubing than Carl's -6 fuel lines.
An additional point, the clearance between the big ends is much tighter than is thought to be "good" these days too. All stokers open up this gap a fair bit. The vacuum will actually make the disc a little stronger too, increasing oiling to the wrist pin.
But given this with no one else ever seeing bluing, or wear to the wrist pins I really would love to see the "fact" Greg is stating with pictures to back it up.
I'd love him to post the pictures showing this like he showed how the factory fuel rails had bigger tubing than Carl's -6 fuel lines.
03-13-2014 | 12:19 PM
#90
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From: Los Altos, CA
Furthermore, pulling vaccuum in the crankcase will cause the disc to be less disrupted and thinner, leading to an even large fraction of the oil spray hitting the wrist pin exactly.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
That's my logic and I am sticking to it until someone comes up with a logical explanation why what I wrote above isn't obviously true.
For example, you're pumping out fluid from the bottom of the engine, so won't that tend to reduce the height (and change the angle) to which the oil will spray? There may well be other effects that increase it, but, without a calculation, can you really assert that one effect is stronger than the other with confidence?
Unless you're going to do FEA, you need to do testing and / or measuring to see the overall result. There's room for many different effects to be in play, some of which may not be entirely intuitive.