Spun a bearing
10-21-2010, 04:14 AM
#31
Rennlist Member
Thread Starter
Alex:
No sarcasm. I just don't understand how people can still be tossing rod bearings out of these engines. We solved all of these problems 10-15 years ago, openly discuss and actively try to help people understand the problems, and yet people keep turning expensive metal into junk.
Seems almost futile, at times.
No sarcasm. I just don't understand how people can still be tossing rod bearings out of these engines. We solved all of these problems 10-15 years ago, openly discuss and actively try to help people understand the problems, and yet people keep turning expensive metal into junk.
Seems almost futile, at times.
I hear where you are coming from, but I have spent enough time on Rennlist to realise that there is no comprehensive and conclusive discussion of dry-sumping the 928. Perhaps the reason is that everyone who has done it has gone down a slightly different route. Mark, Yourself, myself and another 3 UK cars are using the original oil pump as the pressure stage, on the other hand John V. I believe uses an external pressure stage. The UK cars have their tanks in the back, while most of the US cars seem to have the tank furhter fwd. The list of minor differences goes on and on.
Often stuff which comes out as the universal truth on here - for example that IJ crank scrapers solve the 2/6 failure turns out to be not quite right. I had 2 very enjoyable fast laps in a Norwegian well prepperd track GT with the kit at the Nurburgring this Summer and the oil pressure was all over the place. Yet I went out in a '79 5spd with Euro S2 motor, which had the same kit, was driven quicker around and the oil pressure was pegged at 5bar throughout.
What I am getting to with the above, is that it feels that all of us individually have to arrive at our own truths. Sometimes it will be painless, sometimes it will not be. I appreciate guidance along the way and by no means you should feel that your advice is falling on deaf ears - quite the contrary actually!
10-21-2010, 12:08 PM
#32
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Cheburator,
Sorry to hear about your motor. Such track experiences can only be painful. Hearing about others' can often be felt. So I appreciate your sharing it as it truly is helpful for future builds and learning from the experts who have come before.
Now back to the chase.
Regards,
Sorry to hear about your motor. Such track experiences can only be painful. Hearing about others' can often be felt. So I appreciate your sharing it as it truly is helpful for future builds and learning from the experts who have come before.
Now back to the chase.
Regards,
10-21-2010, 03:01 PM
#33
Rennlist
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Greg,
I hear where you are coming from, but I have spent enough time on Rennlist to realise that there is no comprehensive and conclusive discussion of dry-sumping the 928. Perhaps the reason is that everyone who has done it has gone down a slightly different route. Mark, Yourself, myself and another 3 UK cars are using the original oil pump as the pressure stage, on the other hand John V. I believe uses an external pressure stage. The UK cars have their tanks in the back, while most of the US cars seem to have the tank furhter fwd. The list of minor differences goes on and on.
Often stuff which comes out as the universal truth on here - for example that IJ crank scrapers solve the 2/6 failure turns out to be not quite right. I had 2 very enjoyable fast laps in a Norwegian well prepperd track GT with the kit at the Nurburgring this Summer and the oil pressure was all over the place. Yet I went out in a '79 5spd with Euro S2 motor, which had the same kit, was driven quicker around and the oil pressure was pegged at 5bar throughout.
What I am getting to with the above, is that it feels that all of us individually have to arrive at our own truths. Sometimes it will be painless, sometimes it will not be. I appreciate guidance along the way and by no means you should feel that your advice is falling on deaf ears - quite the contrary actually!
I hear where you are coming from, but I have spent enough time on Rennlist to realise that there is no comprehensive and conclusive discussion of dry-sumping the 928. Perhaps the reason is that everyone who has done it has gone down a slightly different route. Mark, Yourself, myself and another 3 UK cars are using the original oil pump as the pressure stage, on the other hand John V. I believe uses an external pressure stage. The UK cars have their tanks in the back, while most of the US cars seem to have the tank furhter fwd. The list of minor differences goes on and on.
Often stuff which comes out as the universal truth on here - for example that IJ crank scrapers solve the 2/6 failure turns out to be not quite right. I had 2 very enjoyable fast laps in a Norwegian well prepperd track GT with the kit at the Nurburgring this Summer and the oil pressure was all over the place. Yet I went out in a '79 5spd with Euro S2 motor, which had the same kit, was driven quicker around and the oil pressure was pegged at 5bar throughout.
What I am getting to with the above, is that it feels that all of us individually have to arrive at our own truths. Sometimes it will be painless, sometimes it will not be. I appreciate guidance along the way and by no means you should feel that your advice is falling on deaf ears - quite the contrary actually!
Oil tank location is moot. Downhill feed the entire way and use -16 hose. Hell, you can put it on the roof, for all I care. All dry sump systems need to be checked and tested....that's part of the installation. When you think you are done, fill the tank to the maximum mark, with the engine running and the oil hot. Spin the engine at redline, while someone watches the oil level, in the tank. Make sure you know that it stabilizes and at what level it stabilizes. If that test works, put it on a chassis dyno and repeat.
I know that Kevin Johnson thinks his windage system cures everything....and I wish it did/could. But it can't/doesn't. There seems to be some people that have had engines fail with his pieces on them...search this Forum. He's a really bright guy and knows volumes about many, many engines. I'm more limited. I've just spent the past 25 years working on the 928 engine.
You are/everyone is welcome to arrive at their own truth. It's your/their time and money.
We have a show/movie over here called "Jackass". They warn people about attempting the stunts they perform at every commercial break, and yet people go out and attempt to do the same exact stupid stunts and kill/mame themselves.
Whatever floats their boat.
__________________
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!
10-21-2010, 03:49 PM
#34
Its getting very difficult to find the red bearing shells. Yellow is mostly what comes now from the sets I bought. I wonder if you could ask specifically for the reds. Obviously most of the glyco ones are blue.
This is post by GregB explaining the differences:
https://rennlist.com/forums/928-foru...ml#post7904489
This is post by GregB explaining the differences:
https://rennlist.com/forums/928-foru...ml#post7904489
10-21-2010, 03:53 PM
#35
Rennlist Member
what rpm are you shifting at and why?
what oil are you using?
The oil pressure isssue could be the change of forces on the rod bearing that then opens the oil hole so that more oil escapes and lowers pressuer under load. without load, that gap might not be there and then pressure goes back up near normal. (just a guess) no other reason that I can think of.
my stock system, is shifted at 6600rpm every shift and has never had any bearing issues over the 15 years I have been racing, trough 4 engines, changed by choice not failure, and 2 others that I built.
all running amsoil, all still alive and running VERY strong today and all have NO modifications to anyting in the oil system. (no accusump, scrapers, drysump, breathers, coolers, etc)
what oil are you using?
The oil pressure isssue could be the change of forces on the rod bearing that then opens the oil hole so that more oil escapes and lowers pressuer under load. without load, that gap might not be there and then pressure goes back up near normal. (just a guess) no other reason that I can think of.
my stock system, is shifted at 6600rpm every shift and has never had any bearing issues over the 15 years I have been racing, trough 4 engines, changed by choice not failure, and 2 others that I built.
all running amsoil, all still alive and running VERY strong today and all have NO modifications to anyting in the oil system. (no accusump, scrapers, drysump, breathers, coolers, etc)
10-21-2010, 05:38 PM
#36
Rennlist Member
Thread Starter
Answers below in bold
what rpm are you shifting at and why?6500 - the powerband is there
what oil are you using?
Castrol RS/TWS 10W60 Formulated for ///M Engines. No, I don't want to hear about Amsoil
The oil pressure isssue could be the change of forces on the rod bearing that then opens the oil hole so that more oil escapes and lowers pressuer under load. without load, that gap might not be there and then pressure goes back up near normal. (just a guess)
I think we determined that it was down to insufficient oil in the tank and the restriction in the oil line. The engine had 15hrs of racing flat out
no other reason that I can think of.
my stock system, is shifted at 6600rpm every shift and has never had any bearing issues over the 15 years I have been racing, trough 4 engines, changed by choice not failure, and 2 others that I built.
all running amsoil, all still alive and running VERY strong today and all have NO modifications to anyting in the oil system. (no accusump, scrapers, drysump, breathers, coolers, etc)
You are the exception, rather than the norm
what oil are you using?
Castrol RS/TWS 10W60 Formulated for ///M Engines. No, I don't want to hear about Amsoil
The oil pressure isssue could be the change of forces on the rod bearing that then opens the oil hole so that more oil escapes and lowers pressuer under load. without load, that gap might not be there and then pressure goes back up near normal. (just a guess)
I think we determined that it was down to insufficient oil in the tank and the restriction in the oil line. The engine had 15hrs of racing flat out
no other reason that I can think of.
my stock system, is shifted at 6600rpm every shift and has never had any bearing issues over the 15 years I have been racing, trough 4 engines, changed by choice not failure, and 2 others that I built.
all running amsoil, all still alive and running VERY strong today and all have NO modifications to anyting in the oil system. (no accusump, scrapers, drysump, breathers, coolers, etc)
You are the exception, rather than the norm
10-21-2010, 10:21 PM
#37
Instructor
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Greg Brown wrote: I'm more limited. I've just spent the past 25 years working on the 928 engine.
) In my profession, I can tell what a client's issues will be and what the "downside" of their situation is almost before they start talking - why - because I have seen their "unique" situation countless times before.Same issue with GB and 928 engines....and he is prepared to help us for free on this board....don't waste the resource and why try to reinvent the wheel?.
PS - When I was about 16 my dad (engineer) saw me using plastigauge on an MG race engine to check bearing clearance...he calmly explained that if I chose not to use proper tools and record journal size, bearing size & clearance etc the cost of any subsequent damage would be met by me....once I was finished measuring, we checked data with plastigauge results and there was enough variation that I've never relied on plastigauge since...YMMV
10-21-2010, 11:39 PM
#38
Rennlist Member
60 weight, probably not great, and "M" engines? what does that have to do with our 928s that seem to respond better to redline, or amsoil. sorry, I had to say it. what i have done, is follow those that have done what I wanted to do, and didnt deviate much. others that have tried to reinvent the wheel, well, look what has happened to them. I have one of the fastest track 928s, been racing them for over 15 years, and never had had any of these issues. If it was just one car, you could say, "fluke" but, its accross about 6-7 engines, and all of them getting beat up pretty bad, running flat out over many many races. Do you remember that the holbert engine had 7 professional 50 min races as well as 100 more club races!! 
scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff.
[/QUOTE]
Castrol RS/TWS 10W60 Formulated for ///M Engines. No, I don't want to hear about Amsoil
I think we determined that it was down to insufficient oil in the tank and the restriction in the oil line. The engine had 15hrs of racing flat out
You are the exception, rather than the norm
scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff. [/QUOTE]
Castrol RS/TWS 10W60 Formulated for ///M Engines. No, I don't want to hear about Amsoil
I think we determined that it was down to insufficient oil in the tank and the restriction in the oil line. The engine had 15hrs of racing flat out
You are the exception, rather than the norm
10-22-2010, 09:19 AM
#39
Rennlist Member
Thread Starter
[QUOTE=mark kibort;7993188]60 weight, probably not great, and "M" engines? what does that have to do with our 928s that seem to respond better to redline, or amsoil. sorry, I had to say it. what i have done, is follow those that have done what I wanted to do, and didnt deviate much. others that have tried to reinvent the wheel, well, look what has happened to them. I have one of the fastest track 928s, been racing them for over 15 years, and never had had any of these issues. If it was just one car, you could say, "fluke" but, its accross about 6-7 engines, and all of them getting beat up pretty bad, running flat out over many many races. Do you remember that the holbert engine had 7 professional 50 min races as well as 100 more club races!! scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff.
What is wrong with 60 weight? You will not tell me that the 928 engine was made to tighter tollerances than the 3.2ltr S54 BMW engine? Please....
50W gets way too thin for my liking in our conditions in Europe in the Summer. Before you ask, yes I did run Redline in my GT engine initially and it burned it like there was no tomorrow the minute the car went anywhere near a race track. Before you allege anything, the engine was totally rebuild with new everything from Porsche. Swapped to Motul Le Mans 15w50 or Castrol RS 10W60 and the problem was resolved. This time I had Castrol lying around and so it went in, next time I will put Motul in.
Mark, I have followed you from the day I joined Rennlist and I admire you a lot for your driving skill and determination. However, I still maintain you are the exception, rather than the norm - funny how all the UK and Germany based racers had problems with 2/6 failure at least once the minute they went racing on slicks. Clearly Porsche was (still is) stupid enough not to run Amsoil and so is BMW in their factory efforts. Last time I checked, they run Mobil and Castrol. But that's been the subject of another discussion already...
scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff. What is wrong with 60 weight? You will not tell me that the 928 engine was made to tighter tollerances than the 3.2ltr S54 BMW engine? Please....
50W gets way too thin for my liking in our conditions in Europe in the Summer. Before you ask, yes I did run Redline in my GT engine initially and it burned it like there was no tomorrow the minute the car went anywhere near a race track. Before you allege anything, the engine was totally rebuild with new everything from Porsche. Swapped to Motul Le Mans 15w50 or Castrol RS 10W60 and the problem was resolved. This time I had Castrol lying around and so it went in, next time I will put Motul in.
Mark, I have followed you from the day I joined Rennlist and I admire you a lot for your driving skill and determination. However, I still maintain you are the exception, rather than the norm - funny how all the UK and Germany based racers had problems with 2/6 failure at least once the minute they went racing on slicks. Clearly Porsche was (still is) stupid enough not to run Amsoil and so is BMW in their factory efforts. Last time I checked, they run Mobil and Castrol. But that's been the subject of another discussion already...
10-22-2010, 09:59 AM
#40
Three Wheelin'
10-22-2010, 01:49 PM
#41
Rennlist Member
so, hold on. again, im not the exception, when done right. joe fan is on slicks now, and has been. Anderson is on slicks, but has modifications. IM on A series hoosiers, almost like slicks. all you need to do , is find the times that your european racers are spinning at a track near you and compare them to super cup GT3 tmes. mine are within 8% of their times. (i.e. 1:37 at laguna vs the supercup times of 1:29).
I havent used redline in a long time, but at the time, it worked great. I was only mentioning it, to not show a total obsession with amsoil. motul, and others are fine too I would imagine. Im not an oil technology engineer but I think by emperial testing, ive found what works. why would you go to a 60 weight. what metrix are you making your decision?
now as far as porsche and bmw using mobil 1?????? you have got to be kidding. these decisions usually have little to do with performance and mostly to do with marketing and MONEY! ive been doing this a long time and know how these agreements work in the business world as well. PLUS there is very little similarity between a 928 engine and a BMW or 911 engine. Do you know the ring gap of the BMW engines, piston tollerances. which model, the S54? is it nicasil? is it alusil??? everything is different. the S54 engine revs to 9000rpm and is nothing like our motor. oiling is different through out the motor, and ours are much more sensitive. Ive done pretty conclusive tests with mobil 1, where the oil pressure light will come on at 260F, where with amsoil, it stays at 5 bar. DRASTIC differences. there is an argument of whether that matters, but I do believe it does.
[QUOTE=Cheburator;7993743]
I havent used redline in a long time, but at the time, it worked great. I was only mentioning it, to not show a total obsession with amsoil. motul, and others are fine too I would imagine. Im not an oil technology engineer but I think by emperial testing, ive found what works. why would you go to a 60 weight. what metrix are you making your decision?
now as far as porsche and bmw using mobil 1?????? you have got to be kidding. these decisions usually have little to do with performance and mostly to do with marketing and MONEY! ive been doing this a long time and know how these agreements work in the business world as well. PLUS there is very little similarity between a 928 engine and a BMW or 911 engine. Do you know the ring gap of the BMW engines, piston tollerances. which model, the S54? is it nicasil? is it alusil???
everything is different. the S54 engine revs to 9000rpm and is nothing like our motor. oiling is different through out the motor, and ours are much more sensitive. Ive done pretty conclusive tests with mobil 1, where the oil pressure light will come on at 260F, where with amsoil, it stays at 5 bar. DRASTIC differences. there is an argument of whether that matters, but I do believe it does.[QUOTE=Cheburator;7993743]
60 weight, probably not great, and "M" engines? what does that have to do with our 928s that seem to respond better to redline, or amsoil. sorry, I had to say it. what i have done, is follow those that have done what I wanted to do, and didnt deviate much. others that have tried to reinvent the wheel, well, look what has happened to them. I have one of the fastest track 928s, been racing them for over 15 years, and never had had any of these issues. If it was just one car, you could say, "fluke" but, its accross about 6-7 engines, and all of them getting beat up pretty bad, running flat out over many many races. Do you remember that the holbert engine had 7 professional 50 min races as well as 100 more club races!! scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff.
What is wrong with 60 weight? You will not tell me that the 928 engine was made to tighter tollerances than the 3.2ltr S54 BMW engine? Please....
50W gets way too thin for my liking in our conditions in Europe in the Summer. Before you ask, yes I did run Redline in my GT engine initially and it burned it like there was no tomorrow the minute the car went anywhere near a race track. Before you allege anything, the engine was totally rebuild with new everything from Porsche. Swapped to Motul Le Mans 15w50 or Castrol RS 10W60 and the problem was resolved. This time I had Castrol lying around and so it went in, next time I will put Motul in.
Mark, I have followed you from the day I joined Rennlist and I admire you a lot for your driving skill and determination. However, I still maintain you are the exception, rather than the norm - funny how all the UK and Germany based racers had problems with 2/6 failure at least once the minute they went racing on slicks. Clearly Porsche was (still is) stupid enough not to run Amsoil and so is BMW in their factory efforts. Last time I checked, they run Mobil and Castrol. But that's been the subject of another discussion already...
scot, my old engine, my 84, engine, my 5 liter part euro, my new stroker, etc etc. Whatever Joe and mark were doing, I am doing for the most part. they were fastest, they were dependable , and when they tried to do something really creative, they had issues. when they found out the reasons for the issues, they either fixed it for all to benefit, or went back to stock stuff. What is wrong with 60 weight? You will not tell me that the 928 engine was made to tighter tollerances than the 3.2ltr S54 BMW engine? Please....
50W gets way too thin for my liking in our conditions in Europe in the Summer. Before you ask, yes I did run Redline in my GT engine initially and it burned it like there was no tomorrow the minute the car went anywhere near a race track. Before you allege anything, the engine was totally rebuild with new everything from Porsche. Swapped to Motul Le Mans 15w50 or Castrol RS 10W60 and the problem was resolved. This time I had Castrol lying around and so it went in, next time I will put Motul in.
Mark, I have followed you from the day I joined Rennlist and I admire you a lot for your driving skill and determination. However, I still maintain you are the exception, rather than the norm - funny how all the UK and Germany based racers had problems with 2/6 failure at least once the minute they went racing on slicks. Clearly Porsche was (still is) stupid enough not to run Amsoil and so is BMW in their factory efforts. Last time I checked, they run Mobil and Castrol. But that's been the subject of another discussion already...
10-22-2010, 01:51 PM
#42
Rennlist Member
also , if you are burning oil like water, you better talk to your rebuilder about that. I dont care if you used "porsche"everything. lots of "porsche everything" motors blow. its how they are rebuilt. I race an entire weekend and barely use a 1/2 quart and almost nothing on the street.
10-22-2010, 02:54 PM
#43
Rennlist Member
Thread Starter
I give up. Clearly this thread has run its useful life. We don't know how to build engines on this side of the pond and we clearly have no clue about anything. I think we determined the cause of the engine failure earlier on, thus let's just leave there. Thank you very much to all those who made useful contributions - your help was appreciated and I did learn something new.
P.S. Most of us racing in the UK also run within 8% of the GT4 boys' times, with the subtle difference we are on Toyo R888s or Michelin Cups. And what does that prove?
P.S. Most of us racing in the UK also run within 8% of the GT4 boys' times, with the subtle difference we are on Toyo R888s or Michelin Cups. And what does that prove?
10-22-2010, 04:17 PM
#44
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One thing I noticed that suddenly the oil pressure went down to 3 bar at full throttle say at 4500rpm. If I kept going to the limiter the oil pressure would not go higher, however if I lifted off, oil pressure on the gauge will climb to 4.5bar. WTF? Only happened during the first race of the day once the engine was hot. In normal road driving it was up at 5 bar and then the big end(s) went. Any ideas? I did have enough oil in the tank before you ask. What would cause the pressure to climb higher even as I have lifted off.
PS - When I was about 16 my dad (engineer) saw me using plastigauge on an MG race engine to check bearing clearance...he calmly explained that if I chose not to use proper tools and record journal size, bearing size & clearance etc the cost of any subsequent damage would be met by me....once I was finished measuring, we checked data with plastigauge results and there was enough variation that I've never relied on plastigauge since...YMMV
10-22-2010, 04:39 PM
#45
Rennlist Member
Thread Starter
Answers in bold below
That's kind of interesting. Are you sure that the oil pump is being driven properly at the high RPM? The oil pump is driven by the timing belt turning the pump's sprocket, which is held to the pump by a key. Under the high RPM there's more load on it as the pump's working to make more pressure there. Maybe a broken key allowing the sprocket to turn on the pump's shaft under the higher load, but getting enough grip to turn more effectively once the RPMs drop again? Just throwing the idea out there since it's something that hasn't been suggested yet.
Brand new oil pump/pulley and key. Everything there is as it should be. Clearly Plastigauge is crap. Can someone enlighten me why Porsche recommended its use in WSM? Rest assured I will use a micrometer when the engine goes back together
I remember seeing a comparison of using Plastigauge to check the clearances vs using precision measuring tools. There's a reason that Plastigauge hasn't put the expensive precision measuring tool people out of business yet.
Brand new oil pump/pulley and key. Everything there is as it should be. Clearly Plastigauge is crap. Can someone enlighten me why Porsche recommended its use in WSM? Rest assured I will use a micrometer when the engine goes back together
I remember seeing a comparison of using Plastigauge to check the clearances vs using precision measuring tools. There's a reason that Plastigauge hasn't put the expensive precision measuring tool people out of business yet.