93 928 gts oil consumption
03-10-2014, 09:53 PM
#46
Rennlist
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Just because it's not printed on the internet in bold type doesn't make it false. (It doesn't make anything true, either.)
If you keep looking in your Reher Morrison book, you will find more little clues!
Look, I understand that not many people here do this stuff for a living....I just happen to do that....and have done the same thing for over 40 years. I've seen more than just one or two of these particular 928 engines apart. I've virtually made a career out of the 928 vehicle (certainly true for the last 20 years.)
You can ignore what I say, or pay attention. In the end, it has very little impact on my life. I know what I know and I'm secure with that. I know that my stuff works. I also know that there are limitations to my pieces and that some engines have "issues" or may be used in such a manner that make them not respond to certain products. (IE....there's no possible way that Andy's engine would have worked in an open road racing event with just my "street" ventilation system.)
The GTS engine has "issues" with pin oiling, in the stock state. Negative crankcase pressure is bound to have a negative effect, in my opinion. There is very little margin left for any negative effect on the wrist pins in the GTS engine.....that is a fact!
Note that I'm not going any farther and talking about any other potential problems that negative crankcase creates, in these engines. There's just no point. The wrist pin oiling issue eliminates negative crankcase pressure, as an option in the GTS engine, all by itself. Pretty simple?
Make your choice, pay your money, have fun!
__________________
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!
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!
Last edited by GregBBRD; 03-10-2014 at 10:09 PM.
03-10-2014, 11:16 PM
#47
Nordschleife Master
I am not trying to pick a fight tonight. I am just trying to understand.
It makes sense that crankcase vacuum causes the oil to flow out faster from pressure fed locations. If oil pressure is say 80 psia at that point, it will flow out faster against 10 psia of air pressure than 14.7 psia of air pressure.
For splash oiling, I don't understand why crankcase vacuum would cause a splash oiling flow out of a part faster. The crankcase vacuum is about the same on all sides, so there's no obvious reason why that would happen.
It is true that piston pumping pulses, those that cause many of the problems with the 928 oiling system, have less energy when the crankcase pressure and density are low. That means that, in the equilibrium, there is less oil in the windage. So overall, splash oiling should probably be less effective with lower crankcase vacuum.
The piston wrist pin is a special case, however. That's because the rod bearing oil spray disk hits very close to between the rod small end and piston pin boss. That part of splash oiling is likely to get better, not worse, with lower crankcase pressure.
Note that I wouldn't expect the pin oiling to get better with crankcase vacuum if the pistons have forced pin oilers drawing mostly from the sides of the bore. But as I hear from you and others, the GTS piston doesn't have those forced pin oilers, so that effect is not there.
Do you disagree with my logic? Or do you have evidence that it's wrong? In case you're bored with the topic, please don't feel compelled to answer. If you don't, I'll just continue my slow progress trying to understand what happens inside my S4 engine.
I have never opened a GTS engine and I've never held a GTS piston in my hand. I have now worked on some S4 engines and I think I am starting to get some idea of what is happening inside there.
One more thing. Surely this crankcase vacuum issues is a matter of a magnitude. If one uses an active pump to keep the crankcase at about atmospheric pressure, surely that can't have any negative effects that a really big crankcase breather hose wouldn't have.
It makes sense that crankcase vacuum causes the oil to flow out faster from pressure fed locations. If oil pressure is say 80 psia at that point, it will flow out faster against 10 psia of air pressure than 14.7 psia of air pressure.
For splash oiling, I don't understand why crankcase vacuum would cause a splash oiling flow out of a part faster. The crankcase vacuum is about the same on all sides, so there's no obvious reason why that would happen.
It is true that piston pumping pulses, those that cause many of the problems with the 928 oiling system, have less energy when the crankcase pressure and density are low. That means that, in the equilibrium, there is less oil in the windage. So overall, splash oiling should probably be less effective with lower crankcase vacuum.
The piston wrist pin is a special case, however. That's because the rod bearing oil spray disk hits very close to between the rod small end and piston pin boss. That part of splash oiling is likely to get better, not worse, with lower crankcase pressure.
Note that I wouldn't expect the pin oiling to get better with crankcase vacuum if the pistons have forced pin oilers drawing mostly from the sides of the bore. But as I hear from you and others, the GTS piston doesn't have those forced pin oilers, so that effect is not there.
Do you disagree with my logic? Or do you have evidence that it's wrong? In case you're bored with the topic, please don't feel compelled to answer. If you don't, I'll just continue my slow progress trying to understand what happens inside my S4 engine.
I have never opened a GTS engine and I've never held a GTS piston in my hand. I have now worked on some S4 engines and I think I am starting to get some idea of what is happening inside there.
One more thing. Surely this crankcase vacuum issues is a matter of a magnitude. If one uses an active pump to keep the crankcase at about atmospheric pressure, surely that can't have any negative effects that a really big crankcase breather hose wouldn't have.
I mean that it is pretty common knowledge that any negative crankcase pressure "draws/sucks" oil out of places that are both pressure and splash fed. Engine builders do many things to compensate....but may not/probably will not print out a giant checklist of things for everyone to follow. They would really rather your engine blew up and you brought it to them for repair, when it comes right down to it.
Just because it's not printed on the internet in bold type doesn't make it false. (It doesn't make anything true, either.)
If you keep looking in your Reher Morrison book, you will find more little clues!
Look, I understand that not many people here do this stuff for a living....I just happen to do that....and have done the same thing for over 40 years. I've seen more than just one or two of these particular 928 engines apart. I've virtually made a career out of the 928 vehicle (certainly true for the last 20 years.)
You can ignore what I say, or pay attention. In the end, it has very little impact on my life. I know what I know and I'm secure with that. I know that my stuff works. I also know that there are limitations to my pieces and that some engines have "issues" or may be used in such a manner that make them not respond to certain products. (IE....there's no possible way that Andy's engine would have worked in an open road racing event with just my "street" ventilation system.)
The GTS engine has "issues" with pin oiling, in the stock state. Negative crankcase pressure is bound to have a negative effect, in my opinion. There is very little margin left for any negative effect on the wrist pins in the GTS engine.....that is a fact!
Note that I'm not going any farther and talking about any other potential problems that negative crankcase creates, in these engines. There's just no point. The wrist pin oiling issue eliminates negative crankcase pressure, as an option in the GTS engine, all by itself. Pretty simple?
Make your choice, pay your money, have fun!
Just because it's not printed on the internet in bold type doesn't make it false. (It doesn't make anything true, either.)
If you keep looking in your Reher Morrison book, you will find more little clues!
Look, I understand that not many people here do this stuff for a living....I just happen to do that....and have done the same thing for over 40 years. I've seen more than just one or two of these particular 928 engines apart. I've virtually made a career out of the 928 vehicle (certainly true for the last 20 years.)
You can ignore what I say, or pay attention. In the end, it has very little impact on my life. I know what I know and I'm secure with that. I know that my stuff works. I also know that there are limitations to my pieces and that some engines have "issues" or may be used in such a manner that make them not respond to certain products. (IE....there's no possible way that Andy's engine would have worked in an open road racing event with just my "street" ventilation system.)
The GTS engine has "issues" with pin oiling, in the stock state. Negative crankcase pressure is bound to have a negative effect, in my opinion. There is very little margin left for any negative effect on the wrist pins in the GTS engine.....that is a fact!
Note that I'm not going any farther and talking about any other potential problems that negative crankcase creates, in these engines. There's just no point. The wrist pin oiling issue eliminates negative crankcase pressure, as an option in the GTS engine, all by itself. Pretty simple?
Make your choice, pay your money, have fun!
Last edited by ptuomov; 03-10-2014 at 11:46 PM.
03-11-2014, 12:36 AM
#48
Instructor
Greg,
Lets suss out the facts here.
I did NOT install the kit, there was boatloads of data from BEFORE I EVER EVEN MET THE FELLOW. I also phoned you to discuss what was happening on the car and you had no suggestions, no one. Then had the audacity to suggest I sabotaged your system, and that no efforts were made to correct it. On top of that, you also have shat on Herman K and others for their efforts for fixing their crankcase ventilation, when effectively your system is exactly the same short of 4 little plates that you attach into the bottom of the cam covers, which you have claimed should 100% fully remove all oil out of the air. Yet you still have the provent on there.
Now you state about what needs to be done to the car if you are running vacuum. If you are running less than 15" Hg of vacuum (which is what I have been running), NO MODIFICATIONS TO THE BUILD ARE REQUIRED. No bearing changes are necessary, no different rings are needed. NOTHING.
If you do swap out to low tension rings, then there are power gains to be had. But there is no harm in running regular standard rings.
If you run over 15" Hg vacuum, then there is a risk of damage to the wrist pin due to the amount of oil removed from the oil cloud. To solve this you need to either rifle drill, or have some other way to supply oil to the wrist pins to prevent seizing.
From GZ Motorsports, the leader in vacuum pumps. "How much vacuum should you use?
You should check with your engine builder as there may be some special issues or firm opinions that they may have. In general GZMS recommends no more than 15" of vacuum in a drag race wet sump application without pressure feeding oil to the wrist pins. In our own in house testing, anything over 12" seemed to offer relatively nominal increases in horsepower (Typically 3-10 more HP between 10" and 15")."
And more, "What do you need to do to build an engine for running a vacuum pump...do you need special seals?
Special seals aren't needed, standard seals like those from Fel-Pro work fine from what we have seen. You need to have your motor sealed well in order for the pump to work. One the worst vacuum leak sources is the oil dipstick - a leak there can cause severe vacuum leaks and it is often overlooked."
In fact, if you talk with ANYONE, or do ANY searching, nothing special is required to run vacuum inside the crankcase. With the system I am making, we see between 9-11" Hg vacuum which is more than enough to help the rings seal and prevent other problems.
I've personally run a vacuum pump system on my own car since Aug 2011, and have many many miles on it. No ill side effects. Even on my S4 motor I noticed that the oil consumption virtually disappeared. I spoke with two other members here on RL who ended up putting pumps on their cars. Alan M who has already posted here. And Ducman (Jake M). Both of them have nothing but good to say.
I had ZERO interest in putting out a kit for this. And did what the owner of the GTS asked me to do to try to get Greg's Kit working. He came and asked me to change the valve stem seals. While we were in there we resealed the intake manifold, and valve covers. Now this car had run Castrol oil, which had built up some inside the covers as it is not an oil with any conditioners. But other than that everything was good. The oil consumption remained a problem and as stated I spoke with Greg about this a couple of times. No suggestions came from him, other than agreeance that it was likely that the rings had some build up in them which might be exasperating the volume of oil getting by the rings. It was discussed opening up Joe's engine and fixing it this way and doing a number of other things. However I had a few theories on the GTS engine which I wished to check. Weeks after discussing the engine overhaul with Joe, I asked him to put a pump on his car and explained the reasoning and gave him a number of things to research. He came back with a go ahead. So I put the bits together, and installed a system onto Joe's car. Instantly there was a massive visual change in the rate of oil consumption that the car had. Additionally, when Joe drove home the first time, he phoned me and said that he couldn't believe how much power the car had, and that I should really put a kit together for this. Since then we have lots of information on his GTS showing that the oil consumption is dropping as time goes on and it's getting better and better.
If anyone wishes to talk to Joe directly about this, feel free to PM me, I will put you in touch and he can tell you the differences.
I will say that Greg did (finally) stand behind his product and did end up giving Joe a partial refund on his kit as it did not work. Though it was not easy, and Joe was a very upset man because of it, and he is not someone who is easily upset.
If anyone wishes to know how Greg's kit claims to work, I can and will send you pictures as to how he does it. It is very easily to replicate should you choose to. Unless of course Greg contacts me privately and "convinces me not to".
As to the system which will be available through Roger, I recommend that anyone interested do their own research and try to find any information regarding the dangers of running 10-15" Hg vacuum in the crankcase. Then make your own educated opinion on what to buy. I will say that when Roger does show it, it will have NO misleading photos, no purposeful misinformation. But it will have a couple of speciality parts that will only be available through him which will make the system what it truly is.
Lets suss out the facts here.
I did NOT install the kit, there was boatloads of data from BEFORE I EVER EVEN MET THE FELLOW. I also phoned you to discuss what was happening on the car and you had no suggestions, no one. Then had the audacity to suggest I sabotaged your system, and that no efforts were made to correct it. On top of that, you also have shat on Herman K and others for their efforts for fixing their crankcase ventilation, when effectively your system is exactly the same short of 4 little plates that you attach into the bottom of the cam covers, which you have claimed should 100% fully remove all oil out of the air. Yet you still have the provent on there.
Now you state about what needs to be done to the car if you are running vacuum. If you are running less than 15" Hg of vacuum (which is what I have been running), NO MODIFICATIONS TO THE BUILD ARE REQUIRED. No bearing changes are necessary, no different rings are needed. NOTHING.
If you do swap out to low tension rings, then there are power gains to be had. But there is no harm in running regular standard rings.
If you run over 15" Hg vacuum, then there is a risk of damage to the wrist pin due to the amount of oil removed from the oil cloud. To solve this you need to either rifle drill, or have some other way to supply oil to the wrist pins to prevent seizing.
From GZ Motorsports, the leader in vacuum pumps. "How much vacuum should you use?
You should check with your engine builder as there may be some special issues or firm opinions that they may have. In general GZMS recommends no more than 15" of vacuum in a drag race wet sump application without pressure feeding oil to the wrist pins. In our own in house testing, anything over 12" seemed to offer relatively nominal increases in horsepower (Typically 3-10 more HP between 10" and 15")."
And more, "What do you need to do to build an engine for running a vacuum pump...do you need special seals?
Special seals aren't needed, standard seals like those from Fel-Pro work fine from what we have seen. You need to have your motor sealed well in order for the pump to work. One the worst vacuum leak sources is the oil dipstick - a leak there can cause severe vacuum leaks and it is often overlooked."
In fact, if you talk with ANYONE, or do ANY searching, nothing special is required to run vacuum inside the crankcase. With the system I am making, we see between 9-11" Hg vacuum which is more than enough to help the rings seal and prevent other problems.
I've personally run a vacuum pump system on my own car since Aug 2011, and have many many miles on it. No ill side effects. Even on my S4 motor I noticed that the oil consumption virtually disappeared. I spoke with two other members here on RL who ended up putting pumps on their cars. Alan M who has already posted here. And Ducman (Jake M). Both of them have nothing but good to say.
I had ZERO interest in putting out a kit for this. And did what the owner of the GTS asked me to do to try to get Greg's Kit working. He came and asked me to change the valve stem seals. While we were in there we resealed the intake manifold, and valve covers. Now this car had run Castrol oil, which had built up some inside the covers as it is not an oil with any conditioners. But other than that everything was good. The oil consumption remained a problem and as stated I spoke with Greg about this a couple of times. No suggestions came from him, other than agreeance that it was likely that the rings had some build up in them which might be exasperating the volume of oil getting by the rings. It was discussed opening up Joe's engine and fixing it this way and doing a number of other things. However I had a few theories on the GTS engine which I wished to check. Weeks after discussing the engine overhaul with Joe, I asked him to put a pump on his car and explained the reasoning and gave him a number of things to research. He came back with a go ahead. So I put the bits together, and installed a system onto Joe's car. Instantly there was a massive visual change in the rate of oil consumption that the car had. Additionally, when Joe drove home the first time, he phoned me and said that he couldn't believe how much power the car had, and that I should really put a kit together for this. Since then we have lots of information on his GTS showing that the oil consumption is dropping as time goes on and it's getting better and better.
If anyone wishes to talk to Joe directly about this, feel free to PM me, I will put you in touch and he can tell you the differences.
I will say that Greg did (finally) stand behind his product and did end up giving Joe a partial refund on his kit as it did not work. Though it was not easy, and Joe was a very upset man because of it, and he is not someone who is easily upset.
If anyone wishes to know how Greg's kit claims to work, I can and will send you pictures as to how he does it. It is very easily to replicate should you choose to. Unless of course Greg contacts me privately and "convinces me not to".
As to the system which will be available through Roger, I recommend that anyone interested do their own research and try to find any information regarding the dangers of running 10-15" Hg vacuum in the crankcase. Then make your own educated opinion on what to buy. I will say that when Roger does show it, it will have NO misleading photos, no purposeful misinformation. But it will have a couple of speciality parts that will only be available through him which will make the system what it truly is.
When Colin suggested I try his vacuum system in late October 2013 I agreed and have had it in place since then (about 3,000 km/1,890 miles ago). The first thing that I noticed as Colin pointed out was a very much stronger and faster performance. Additionally my oil consumption is about 5x better than it was previously. I did change from Castrol GTX 20/50 to Mobil 1 15/50 but that is the only change aside from the the installation of the vacuum system.
I can't generalize about other GTSs or other 928 models but for me I see a huge improvement. Gone are the big clouds of blue smoke upon acceleration and long gone is the qt/500 mile oil consumption. I feel a real improvement in engine power and performance via the seat-of-the pants meter. I am very happy.
All the best,
Joe
I have had Colin's vacuum system in place since the end of October and can report that oil consumption is about 5x better than before with 1qt/2400 miles.
As Colin also notes there is a very noticeable
03-11-2014, 01:01 AM
#49
Nordschleife Master
1. the shape of the body above the rear wheel arches
2. the pollen filter
They can keep the rest
Otherwise, give me an 89 with LSD any day of the week!
One engine ended up on ebay and the ebay ads have been discussed on this forum a couple of times, and the other with the smoking problem (in England.. hate to think how much *that* cost, between shipping and 17.5% VAT) is sitting while the owner recovers his love of 928's by working on other cars.
Lots of interesting stuff coming out in this discussion - hopefully the swords can stay in their scabbards and the technical stuff can continue to be debated!
(btw - "Seriously, this might be the worst idea anyone has ever had, for these engines" might be taken a little personally - its not like this discussion is taking place face to face over a beer. but that's the problematic nature of online forums, and why ****fights happen).
03-11-2014, 01:16 AM
#50
Addict
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I have often said the ULTIMATE expression of the 928 was and is an 89 GT ..... 5 spd , normal lsd, no airbags (which easily total a car) , the bigger cams to make it rev.....after that it was all down hill ...
03-11-2014, 01:37 AM
#51
Nordschleife Master
Greg,
The gay banter comment was from Monty Python, british humour.
We could both go on and on. I've said my piece regarding what happened. And so long as you continue to accuse me of sabotage, and being self serving regarding what happened, I will continue to share the small differences that you do to your kit so that others can make a more educated decision as to what to buy.
And if Reher Morrison is so against vacuum pumps, why do they sell kit's specifically for domestic engines? http://rehermorrison.com/product/vacuum-pump-kit/
They do talk about the oil draining back from the heads as nearly stalling due to the vacuum. But as I'm drawing from the crankcase, this completely eliminates this. In fact the heads will drain back substantially better with my setup than any setup which vents from the valve covers due to the lack of airflow going up and out of the heads with mine.
One last thing, I have never seen a blued GTS wrist pin. As you're the expert, maybe you can supply us with a number of pictures of them? As I've scoured every GTS thread on Rennlist, pelican, and other sites and have found numerous GTS engine threads relating to the pistons etc. in not even one of them was there even the slightest mention of this. Even in threads that you contributed to, yet you'd think if it was such a problem and they all needed to be replaced, you would have mentioned it. Or how about the thread with the fellow who had the GT who had a rust pit on his wrist pins and you sold him a brand new set for $100 that came out of a new set of factory pistons as they were not needed.
If any of the others who have opened a number of GTS engines could chime in on the blued wrist pins, it would be most appreciated.
And Hilton has it correct above.
The gay banter comment was from Monty Python, british humour.
We could both go on and on. I've said my piece regarding what happened. And so long as you continue to accuse me of sabotage, and being self serving regarding what happened, I will continue to share the small differences that you do to your kit so that others can make a more educated decision as to what to buy.
And if Reher Morrison is so against vacuum pumps, why do they sell kit's specifically for domestic engines? http://rehermorrison.com/product/vacuum-pump-kit/
They do talk about the oil draining back from the heads as nearly stalling due to the vacuum. But as I'm drawing from the crankcase, this completely eliminates this. In fact the heads will drain back substantially better with my setup than any setup which vents from the valve covers due to the lack of airflow going up and out of the heads with mine.
One last thing, I have never seen a blued GTS wrist pin. As you're the expert, maybe you can supply us with a number of pictures of them? As I've scoured every GTS thread on Rennlist, pelican, and other sites and have found numerous GTS engine threads relating to the pistons etc. in not even one of them was there even the slightest mention of this. Even in threads that you contributed to, yet you'd think if it was such a problem and they all needed to be replaced, you would have mentioned it. Or how about the thread with the fellow who had the GT who had a rust pit on his wrist pins and you sold him a brand new set for $100 that came out of a new set of factory pistons as they were not needed.
If any of the others who have opened a number of GTS engines could chime in on the blued wrist pins, it would be most appreciated.
And Hilton has it correct above.
03-11-2014, 02:21 AM
#52
Rennlist
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Pretty clearly, I've stated what I feel the problem with a vacuum pump on a GTS engine is.
This is totally my opinion, from studying the problems with the oiling system on a GTS engine and seeing the resulting pieces, when the engines are disassembled.
I believe I should be entitled to having my own opinion, without being attacked, lied to, having my words twisted around, or threatened.
I really have nothing more to add and feel that any more debate, on my part, is a complete waste of time.
Let's sit back and see what happens.
This is totally my opinion, from studying the problems with the oiling system on a GTS engine and seeing the resulting pieces, when the engines are disassembled.
I believe I should be entitled to having my own opinion, without being attacked, lied to, having my words twisted around, or threatened.
I really have nothing more to add and feel that any more debate, on my part, is a complete waste of time.
Let's sit back and see what happens.
03-11-2014, 04:21 AM
#53
Rennlist
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Greg,
The gay banter comment was from Monty Python, british humour.
We could both go on and on. I've said my piece regarding what happened. And so long as you continue to accuse me of sabotage, and being self serving regarding what happened, I will continue to share the small differences that you do to your kit so that others can make a more educated decision as to what to buy.
And if Reher Morrison is so against vacuum pumps, why do they sell kit's specifically for domestic engines? http://rehermorrison.com/product/vacuum-pump-kit/
They do talk about the oil draining back from the heads as nearly stalling due to the vacuum. But as I'm drawing from the crankcase, this completely eliminates this. In fact the heads will drain back substantially better with my setup than any setup which vents from the valve covers due to the lack of airflow going up and out of the heads with mine.
One last thing, I have never seen a blued GTS wrist pin. As you're the expert, maybe you can supply us with a number of pictures of them? As I've scoured every GTS thread on Rennlist, pelican, and other sites and have found numerous GTS engine threads relating to the pistons etc. in not even one of them was there even the slightest mention of this. Even in threads that you contributed to, yet you'd think if it was such a problem and they all needed to be replaced, you would have mentioned it. Or how about the thread with the fellow who had the GT who had a rust pit on his wrist pins and you sold him a brand new set for $100 that came out of a new set of factory pistons as they were not needed.
If any of the others who have opened a number of GTS engines could chime in on the blued wrist pins, it would be most appreciated.
And Hilton has it correct above.
The gay banter comment was from Monty Python, british humour.
We could both go on and on. I've said my piece regarding what happened. And so long as you continue to accuse me of sabotage, and being self serving regarding what happened, I will continue to share the small differences that you do to your kit so that others can make a more educated decision as to what to buy.
And if Reher Morrison is so against vacuum pumps, why do they sell kit's specifically for domestic engines? http://rehermorrison.com/product/vacuum-pump-kit/
They do talk about the oil draining back from the heads as nearly stalling due to the vacuum. But as I'm drawing from the crankcase, this completely eliminates this. In fact the heads will drain back substantially better with my setup than any setup which vents from the valve covers due to the lack of airflow going up and out of the heads with mine.
One last thing, I have never seen a blued GTS wrist pin. As you're the expert, maybe you can supply us with a number of pictures of them? As I've scoured every GTS thread on Rennlist, pelican, and other sites and have found numerous GTS engine threads relating to the pistons etc. in not even one of them was there even the slightest mention of this. Even in threads that you contributed to, yet you'd think if it was such a problem and they all needed to be replaced, you would have mentioned it. Or how about the thread with the fellow who had the GT who had a rust pit on his wrist pins and you sold him a brand new set for $100 that came out of a new set of factory pistons as they were not needed.
If any of the others who have opened a number of GTS engines could chime in on the blued wrist pins, it would be most appreciated.
And Hilton has it correct above.
Worth making a couple of comments.
Colin:
I'm sincerely sorry for your language/reading comprehension issues with the English language.....which must be the reason that you keep twisting around things that I say...just like this.
I never said (or suggested) that Reher Morrison did not use/like vacuum pumps....that would be completely stupid. I simply stated that their book had a few references about what was need when a negative crankcase pressure system was used. (Vacuum pump or dry sump pump induced.)
They do not tell all....that would be a bad business model.....just like I never tell everything I know, here on Rennlist. That would also be a bad business model. Instead, I choose to carefully pick topics that I have studied and that I have information and opinions about....like the issue with the GTS wrist pin oiling.
You know what....as a final comment, why don't you share with us why you think that a piston without oil return holes in the oil control ring can possibly properly lubricate a wrist pin, since about 90% of the oil for the pin comes from that source.
I also find it humorous that you keep referring to what GZ Motorsports has to say. You claim they say that it is ok for people to use 15 inches of vacuum and still have proper pin oiling.....and anything more than this requires forced pin oiling. Obviously to everyone, their data is gathered from engines that have pin oiling from under the oil control ring. I know, for a fact, that their total experience with engines that have no oil return holes in the oil control ring is......well.....zero. Maybe you should stop for a minute and ask them what they think about this problem.....I certainly have, when I was doing research on this subject.....and they are one of the people that made me abandon a vacuum pump for the GTS application.
Try and keep in mind that your S4 "test car" is not a GTS. You have oil return holes in your pistons. I have never questioned that this should work. Try to keep up.....
I believe this thread is specifically about the GTS engine.....which is what I'm talking about......not S4 or GT engines.....
Try to read and understand what I write....even if it takes someone to help you with the translation. This may help you from twisting what I say around, to the extent that you seem to do. I do understand that this entire English as a second language, in Canada, can be a real problem.
03-11-2014, 09:54 AM
#54
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Rennlist Member
Rennlist Member
I have seen three GTS engine internals myself and know three other locally dismatled engines. None of these have had any problems in wrist pins or clips. Besides cranks, wrist pins have been best condition parts to come out inside engine block. Five out of six have seen hard autobahn use for first 100+ K miles of their life. Usual thrust bearing failure, cracked cylinder walls and worn out bores seem to be common in here.
03-11-2014, 10:34 AM
#55
Rennlist Member
A lot going back and forth
I guess my question is if my late 93 GTS has not shown any noticeable oil consumption in 15k miles use with oil changes every 2500-3000 miles do i need to be concerned?
I guess my question is if my late 93 GTS has not shown any noticeable oil consumption in 15k miles use with oil changes every 2500-3000 miles do i need to be concerned?
03-11-2014, 10:48 AM
#56
Rennlist Member
I have seen three GTS engine internals myself and know three other locally dismatled engines. None of these have had any problems in wrist pins or clips. Besides cranks, wrist pins have been best condition parts to come out inside engine block. Five out of six have seen hard autobahn use for first 100+ K miles of their life. Usual thrust bearing failure, cracked cylinder walls and worn out bores seem to be common in here.
Never seen that problem in another 4 street GTS engines - both early (non-drilled) and late MYs.
Btw, Greg, you are being disingenious - 1994 and 95 MY GTS pistons are definitely drilled from the factory...
03-11-2014, 12:16 PM
#57
89GT's rock.. end of discussion
03-11-2014, 02:14 PM
#58
Nordschleife Master
Thank you both Erkka, and Alex for weighting in. 
Two more people whom have not seen blued wrist pins in GTS motors.
This I think dispels your "fact" about GTS wrist pins having oiling problems Greg. Unless you care to share with us a bunch of pictures showing the bluing. If you have them, I would be very interested to see them.
Now I have attached 3 pictures (one borrowed from a post Rob Edwards posted, If you want it down Rob, please ask!), of GTS pistons. The design of the GTS pistons is an older design, newer pistons forgo the ridge below the wrist pin as they found it increases drag without aiding to much life. However for the oiling of the wrist pin in a piston that has no oil drain back holes, this is a benefit as it will trap a slight bit of oil in this location aiding in the oiling of the wrist pins. This coupled with the exceptionally high rate of windage inside the GTS crankcase is why I do not believe that wrist pin oiling is going to be an issue for the motor with mild vacuum.
When I did my research, I contacted numerous companies regarding crankcase vacuum and what would be needed. As well as countless hours of online research as well. I did not just contact one company and base everything off of their word. There are many engine builders that I spoke to originally who stated that if the engine has a robust wrist pin you can run as much vacuum as you want without fear of the wrist pin failing. I then have based what I have stated on the most conservative figures that I have found.
Since what Greg has stated I have done more research, made more calls, and cannot backup any of what he has said as "fact".
GZ motorsports said that the wrist pins would be mostly fed by splash if the factory had not added the holes and that adding vacuum would not affect this splash at all. I talked to Greg's Reher Morrison to ask their opinion, they said they make zero changes, run around 10"Hg vacuum and HIGHLY recommend them to everyone regardless of what they are building unless they can afford a full on drysump system.
To Jim and Tom,
There are things about each model that I like more and less.
I love the GTS flares as do most, but I also love the rawness that came from the 86 euroS. I find that the even the GT compared to the late EuroS cars were undercammed, and were not as exciting to drive. This is one of the reasons I proceeded to have my camshafts made, because I prefer the way the 32V engines work, but wanted more power and freer revving.
Two more people whom have not seen blued wrist pins in GTS motors.
This I think dispels your "fact" about GTS wrist pins having oiling problems Greg. Unless you care to share with us a bunch of pictures showing the bluing. If you have them, I would be very interested to see them.
Now I have attached 3 pictures (one borrowed from a post Rob Edwards posted, If you want it down Rob, please ask!), of GTS pistons. The design of the GTS pistons is an older design, newer pistons forgo the ridge below the wrist pin as they found it increases drag without aiding to much life. However for the oiling of the wrist pin in a piston that has no oil drain back holes, this is a benefit as it will trap a slight bit of oil in this location aiding in the oiling of the wrist pins. This coupled with the exceptionally high rate of windage inside the GTS crankcase is why I do not believe that wrist pin oiling is going to be an issue for the motor with mild vacuum.
When I did my research, I contacted numerous companies regarding crankcase vacuum and what would be needed. As well as countless hours of online research as well. I did not just contact one company and base everything off of their word. There are many engine builders that I spoke to originally who stated that if the engine has a robust wrist pin you can run as much vacuum as you want without fear of the wrist pin failing. I then have based what I have stated on the most conservative figures that I have found.
Since what Greg has stated I have done more research, made more calls, and cannot backup any of what he has said as "fact".
GZ motorsports said that the wrist pins would be mostly fed by splash if the factory had not added the holes and that adding vacuum would not affect this splash at all. I talked to Greg's Reher Morrison to ask their opinion, they said they make zero changes, run around 10"Hg vacuum and HIGHLY recommend them to everyone regardless of what they are building unless they can afford a full on drysump system.
To Jim and Tom,
There are things about each model that I like more and less.
I love the GTS flares as do most, but I also love the rawness that came from the 86 euroS. I find that the even the GT compared to the late EuroS cars were undercammed, and were not as exciting to drive. This is one of the reasons I proceeded to have my camshafts made, because I prefer the way the 32V engines work, but wanted more power and freer revving.
03-11-2014, 02:48 PM
#59
Archive Gatekeeper
Rennlist Member
Rennlist Member
You can use whatever pics I've posted, IMO anything that gets posted on the internet might as well be public domain.
Somewhere I have the remaining pistons and rods from my blown up GTS motor- couldn't find them last night but I think they're in the other garage. I'll try to find them and shoot pics of the wrist pins. I have no recollection of what color they were, I was too busy looking at the other carnage from that oiling failure.
Somewhere I have the remaining pistons and rods from my blown up GTS motor- couldn't find them last night but I think they're in the other garage. I'll try to find them and shoot pics of the wrist pins. I have no recollection of what color they were, I was too busy looking at the other carnage from that oiling failure.