How many 15-16 gt3's have engine replaced?
07-22-2016 | 03:06 PM
#871
Racer
Joined: Mar 2015
Posts: 288
Likes: 31
From: Iowa
Macca, I believe you've mentioed before that you think it's a cold start issue wearing off the DLC then high rpms causing the damage after that. This makes the most sense to me. Do you think an accusump could be a reasonable fix for everyone? They are relatively inexpensive and used by most race teams if I understand correctly and possibly the reason it's not seen in Porsche's race cars??
07-22-2016 | 03:07 PM
#872
Nordschleife Master
Joined: Apr 2010
Posts: 9,991
Likes: 386
From: Ny
Firstly I'm disappointed the G engines fail as well.
Secondly I commend the aftermarket for the fact that they are working on a solution. It would be amazing if you guys pull it off and a great business opportunity.
However lastly,please do not take this part the wrong way,but I have big doubts considering your resources in comparison to those available at PAG's disposal...
Secondly I commend the aftermarket for the fact that they are working on a solution. It would be amazing if you guys pull it off and a great business opportunity.
However lastly,please do not take this part the wrong way,but I have big doubts considering your resources in comparison to those available at PAG's disposal...
07-22-2016 | 03:39 PM
#874
Rennlist Member
Joined: Aug 2014
Posts: 2,642
Likes: 1,092
From: Antipodes
If the garage confirms that I need an engine replacement, then it won't be due to over reving on cold starts. I have been religious about getting the engine up to temp before giving it the beans so it must be something else.
07-22-2016 | 03:58 PM
#875
Racer
Joined: Mar 2015
Posts: 288
Likes: 31
From: Iowa
I dont think it's from over revving on cold starts. But lack of lubrication the first 5 seconds until oil circulates.
07-22-2016 | 04:24 PM
#877
Nordschleife Master
Joined: Apr 2010
Posts: 9,991
Likes: 386
From: Ny
Without sounding like I'm lacking modesty,I speculated a long time ago that this might be a cold start lubrication problem that manifests later and at higher RPM. I don't remember if Macca agrees and/or he has a different theory... However,this is where many make the confusion : I don't suspect it's lack of lubrication because of the owner's negligence...which would mean revving the heck out of the engine before it reached the operating temperature. This is what I suspect :
New engines suffer from what's referred to as " dry start ". New components inside an engine take time to develop an oil film that covers them at all times. Even if you drain the oil entirely and start the engine for a few seconds,you might be ok and not damage anything because of the oil film that covers its parts. Of course,DO NOT ever try that! " Dry start " happens in new engines that have not developed a solid oil film. Of course,modern oils,modern manufacturing and the use of assembly lube greatly have reduced " dry start ". But IMO,this is when most wear continues to happen inside an engine.
So,it's unavoidable...it is not the result of you doing something wrong...
You might ask : " how come it manifests only at higher RPM ? " Valid question. In order for the engine to make most power,the DME demands the Variocam high lift and high duration from the opening of the valves. The DME is highly accurate. Any scoring on the cam lobe that will interfere with the valve opening that the DME wants to see and it will misfire triggering the " Reduced performance ".
Anyway...just my theory and 2c FWIW...
New engines suffer from what's referred to as " dry start ". New components inside an engine take time to develop an oil film that covers them at all times. Even if you drain the oil entirely and start the engine for a few seconds,you might be ok and not damage anything because of the oil film that covers its parts. Of course,DO NOT ever try that! " Dry start " happens in new engines that have not developed a solid oil film. Of course,modern oils,modern manufacturing and the use of assembly lube greatly have reduced " dry start ". But IMO,this is when most wear continues to happen inside an engine.
So,it's unavoidable...it is not the result of you doing something wrong...
You might ask : " how come it manifests only at higher RPM ? " Valid question. In order for the engine to make most power,the DME demands the Variocam high lift and high duration from the opening of the valves. The DME is highly accurate. Any scoring on the cam lobe that will interfere with the valve opening that the DME wants to see and it will misfire triggering the " Reduced performance ".
Anyway...just my theory and 2c FWIW...
07-22-2016 | 04:28 PM
#878
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07-22-2016 | 05:26 PM
#879
Pro
Joined: Dec 2014
Posts: 521
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From: Texas
Hi Guys,
We've been working on this in the background for a while now. We've partnered with Performance Developments. Been consulting and having parts finishing up design as I type this. I know you'll have many questions and we can't share much right now. But just know that your car after the warranty period will not be junk and you won't be cursed with purchasing new engines to keep it alive.
The issue that has caused component failures in the new 991 GT3 engines requiring some engines to be replaced and others to have just Cylinder heads replaced has sparked a fear and concerned amongst the owners that seems to grow each day. This is to inform you that we know the root cause, have a solution designed and the parts in production.
The resulting damage is due to a lack of lubrication. We know the cause and the solution is to regain the oil film lost in the present design. Coatings are used to reduce friction but it is expected that an oil film would be present at sometime during the rotation of the camshaft. Unfortunately it isn’t resulting in the damage.
The action of the Camshaft lobe when in contact with the finger is a high contact stress type, or sliding contact. This is where the coatings used come into play. They help lower the contact friction and wear. This stress contact is moving across the face of the finger and not localized in one spot. However coatings cannot solve the root cause of the problem. An oil film is still required in the cycle.
Changes to Oil pressure and coatings may prolong the inevitable but this is a case of when not if. Factor in the warranty period and now you have a real dilemma for the car owner. Should I wait, should I go with the OEM and will the OEM honor the fault after my warranty is expired. Only the OEM can answer those questions. In the meantime we will have a “fix” very soon for those that do not wish to wait and hope that the OEM will take care of the problem.
Many will ask, “what is this root cause, why should I believe you”?
We know the cause and we have a solution. It will be made known when we have the replacement parts available. In the meantime, we do not wish to give our competitors a free lunch. It makes no difference now if it’s known or not as the parts are not yet available. We do not want to add to the fear but to inform you we have a mechanical solution. It was hoped that the OE would do this but it appears from what has being done to date, the root cause was not addressed and a “band aid” was provided.
Remember, this is a “when not if” problem.
We've been working on this in the background for a while now. We've partnered with Performance Developments. Been consulting and having parts finishing up design as I type this. I know you'll have many questions and we can't share much right now. But just know that your car after the warranty period will not be junk and you won't be cursed with purchasing new engines to keep it alive.
The issue that has caused component failures in the new 991 GT3 engines requiring some engines to be replaced and others to have just Cylinder heads replaced has sparked a fear and concerned amongst the owners that seems to grow each day. This is to inform you that we know the root cause, have a solution designed and the parts in production.
The resulting damage is due to a lack of lubrication. We know the cause and the solution is to regain the oil film lost in the present design. Coatings are used to reduce friction but it is expected that an oil film would be present at sometime during the rotation of the camshaft. Unfortunately it isn’t resulting in the damage.
The action of the Camshaft lobe when in contact with the finger is a high contact stress type, or sliding contact. This is where the coatings used come into play. They help lower the contact friction and wear. This stress contact is moving across the face of the finger and not localized in one spot. However coatings cannot solve the root cause of the problem. An oil film is still required in the cycle.
Changes to Oil pressure and coatings may prolong the inevitable but this is a case of when not if. Factor in the warranty period and now you have a real dilemma for the car owner. Should I wait, should I go with the OEM and will the OEM honor the fault after my warranty is expired. Only the OEM can answer those questions. In the meantime we will have a “fix” very soon for those that do not wish to wait and hope that the OEM will take care of the problem.
Many will ask, “what is this root cause, why should I believe you”?
We know the cause and we have a solution. It will be made known when we have the replacement parts available. In the meantime, we do not wish to give our competitors a free lunch. It makes no difference now if it’s known or not as the parts are not yet available. We do not want to add to the fear but to inform you we have a mechanical solution. It was hoped that the OE would do this but it appears from what has being done to date, the root cause was not addressed and a “band aid” was provided.
Remember, this is a “when not if” problem.
07-22-2016 | 06:06 PM
#881
Three Wheelin'
Joined: Feb 2003
Posts: 1,666
Likes: 2
Without sounding like I'm lacking modesty,I speculated a long time ago that this might be a cold start lubrication problem that manifests later and at higher RPM. I don't remember if Macca agrees and/or he has a different theory... However,this is where many make the confusion : I don't suspect it's lack of lubrication because of the owner's negligence...which would mean revving the heck out of the engine before it reached the operating temperature. This is what I suspect :
New engines suffer from what's referred to as " dry start ". New components inside an engine take time to develop an oil film that covers them at all times. Even if you drain the oil entirely and start the engine for a few seconds,you might be ok and not damage anything because of the oil film that covers its parts. Of course,DO NOT ever try that! " Dry start " happens in new engines that have not developed a solid oil film. Of course,modern oils,modern manufacturing and the use of assembly lube greatly have reduced " dry start ". But IMO,this is when most wear continues to happen inside an engine.
So,it's unavoidable...it is not the result of you doing something wrong...
You might ask : " how come it manifests only at higher RPM ? " Valid question. In order for the engine to make most power,the DME demands the Variocam high lift and high duration from the opening of the valves. The DME is highly accurate. Any scoring on the cam lobe that will interfere with the valve opening that the DME wants to see and it will misfire triggering the " Reduced performance ".
Anyway...just my theory and 2c FWIW...
New engines suffer from what's referred to as " dry start ". New components inside an engine take time to develop an oil film that covers them at all times. Even if you drain the oil entirely and start the engine for a few seconds,you might be ok and not damage anything because of the oil film that covers its parts. Of course,DO NOT ever try that! " Dry start " happens in new engines that have not developed a solid oil film. Of course,modern oils,modern manufacturing and the use of assembly lube greatly have reduced " dry start ". But IMO,this is when most wear continues to happen inside an engine.
So,it's unavoidable...it is not the result of you doing something wrong...
You might ask : " how come it manifests only at higher RPM ? " Valid question. In order for the engine to make most power,the DME demands the Variocam high lift and high duration from the opening of the valves. The DME is highly accurate. Any scoring on the cam lobe that will interfere with the valve opening that the DME wants to see and it will misfire triggering the " Reduced performance ".
Anyway...just my theory and 2c FWIW...
07-22-2016 | 06:17 PM
#882
Nordschleife Master
Joined: Apr 2010
Posts: 9,991
Likes: 386
From: Ny
Yes,that's what I said : all engines...better yet,all new engines,because if you've opened a well used engine,you will see the oil film that covers all the components. But in the GT3's case,many of these cars sit in the garage for days/weeks at a time,so all the oil drains into the crankcase. If there's indeed a design/oil volume issue,the wear we see would develop in the very short time after you've started the engine and not at high RPMs when the oil is pumped like mad through the engine...
07-22-2016 | 06:21 PM
#883
Rennlist Member
Joined: Apr 2002
Posts: 14,140
Likes: 14
From: New Zealand
I do not recall having a specific theory on the wear occurring at high or low revs. To the contrary the factory have been playing with the mid rpm oil pressure thus lubrication....nick also brings up some valid points.
Chris thanks for confirming a G engine failure. Hopefully this is not the same tech that thought EX on the crate was the engine serial? I have head failures of RS engines over in the German series but still yet we have no first hand encounter although I'm sure over to me we will.
Jamie's team have done a commendable job working through the issues from an engineering standpoint. I understand they have identified a potential weak spot with the dLC finger rocks holding a viscous coating which is most likely blamed for high wear on the pad. I'm sure much work has gone into this and if it yields an aftermarket solution to end the issue for all time - that would be a huge win and put the 991 RS MA176 and MA175 engines on a reliable footing for current and future owners.
Chris thanks for confirming a G engine failure. Hopefully this is not the same tech that thought EX on the crate was the engine serial? I have head failures of RS engines over in the German series but still yet we have no first hand encounter although I'm sure over to me we will.
Jamie's team have done a commendable job working through the issues from an engineering standpoint. I understand they have identified a potential weak spot with the dLC finger rocks holding a viscous coating which is most likely blamed for high wear on the pad. I'm sure much work has gone into this and if it yields an aftermarket solution to end the issue for all time - that would be a huge win and put the 991 RS MA176 and MA175 engines on a reliable footing for current and future owners.
07-22-2016 | 06:40 PM
#884
Nordschleife Master
Joined: Apr 2010
Posts: 9,991
Likes: 386
From: Ny
This is a pic I have borrowed from BBI's build thread. If they have a problem with me displaying their photo,please let me know and I'll remove it immediately.
As you can see,the cams are displayed in this photo. I don't suspect they have put them through steam cleaning because it wouldn't make sense in such a low mileage engine,plus you can see a very thin oil film on the cam. Please disregard the red assembly lube,which I suspect has been placed there for re-assembly.
That is pretty much most of the oil film these components will have on them during a dry start,especially after the car has been sitting for a while.
As you can see,the cams are displayed in this photo. I don't suspect they have put them through steam cleaning because it wouldn't make sense in such a low mileage engine,plus you can see a very thin oil film on the cam. Please disregard the red assembly lube,which I suspect has been placed there for re-assembly.
That is pretty much most of the oil film these components will have on them during a dry start,especially after the car has been sitting for a while.
Last edited by neanicu; 08-31-2016 at 09:03 AM.
07-22-2016 | 07:25 PM
#885
Racer
Joined: Mar 2015
Posts: 288
Likes: 31
From: Iowa
Maybe it was neanicu who initially suggested but I agree with him. Sounds like possibly the DLC coated fingers don't like to hold an oil film for whatever reason. So back to my original question. Does anybody think an accusump system that builds oil pressure and circulation prior to starting would be beneficial?