991.1 GT3RS failures
12-02-2020, 10:52 PM
#92
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We are often "un" privileged to see things we never want to see. We saw this back a few years when asked us to build a 991.1 hot rod. Opening the engine we saw the finger follower issue. Immediately the build was stopped as we had to solve this issue first. The solid conversion was completed and soon after Porsche kind of admitted to the failure by offering the extended warranty.
Then came the 991.2 engine projects. In the middle of the production of new parts we became aware of two engine failures, exactly the same failure, in the exact same position in the engine, which again has stalled the builds of the two 991.2 engines. We have now another serious issue to understand and fix before we continue.
New 991.2 blocks are very expensive and unavailable unless you have a ticket written up by a Porsche agency tech for an engine failure. They are not available through the Porsche parts system to "outsiders" like me. I wonder why this is??
So we have to do our own repair. Oversize bearing shells are not available either, so we found some that will work by narrowing the shell length and line boring the block. To say this issue is not serious, baffles me. We saw the same thing with the .1 engine issue. I think human nature plays games with us when confronted with things we don't want to believe. Why, because it may cost us a lot of money. We would rather believe it doesn't exist , so then hopefully it won't happen to me. Unfortunately, this is not the world I live in with respect to broken engines. I cannot disregard an issue and say, well its a 1 time thing so lets keep building hot rods.
The same customer who thinks its not serious and "I have never heard of any issues" would jump all over my *** if I built him or her an engine and the failure was to happen. I can hear them now, you should have done something if you knew.
"O" the world of an engine builder. My favorite saying is, "nothing will humble a man more than an engine or an angry wife". And so we continue to try to understand the failure, the cause and create a fix.
nh
Then came the 991.2 engine projects. In the middle of the production of new parts we became aware of two engine failures, exactly the same failure, in the exact same position in the engine, which again has stalled the builds of the two 991.2 engines. We have now another serious issue to understand and fix before we continue.
New 991.2 blocks are very expensive and unavailable unless you have a ticket written up by a Porsche agency tech for an engine failure. They are not available through the Porsche parts system to "outsiders" like me. I wonder why this is??
So we have to do our own repair. Oversize bearing shells are not available either, so we found some that will work by narrowing the shell length and line boring the block. To say this issue is not serious, baffles me. We saw the same thing with the .1 engine issue. I think human nature plays games with us when confronted with things we don't want to believe. Why, because it may cost us a lot of money. We would rather believe it doesn't exist , so then hopefully it won't happen to me. Unfortunately, this is not the world I live in with respect to broken engines. I cannot disregard an issue and say, well its a 1 time thing so lets keep building hot rods.
The same customer who thinks its not serious and "I have never heard of any issues" would jump all over my *** if I built him or her an engine and the failure was to happen. I can hear them now, you should have done something if you knew.
"O" the world of an engine builder. My favorite saying is, "nothing will humble a man more than an engine or an angry wife". And so we continue to try to understand the failure, the cause and create a fix.
nh
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Dundon Motorsports
Gig Harbor, WA
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Dundon Motorsports
Gig Harbor, WA
253-200-4454
jamie@dundonmotorsports.com
www.dundonmotorsports.com
Facebook.com/dundonmotorsports
Instagram @dundon_motorsports
12-03-2020, 02:29 PM
#93
Rennlist Member
These cases are junk. They move all over the place. I just bought a new case for a customer whose block was cracked and we probed it. Bores and deck are all over the place. They run out of the box about .0007-.0008" total piston to cylinder clearance, but there were spots in the bore where there is negative clearance. That can't be good. Turn up the horsepower and we quickly find the weakest link as Neil has so kindly shared with us.
I can recall reading in the SAE magazine a few years back where Porsche was able to reduce the amount of aluminum they use by a few kilograms in these engine blocks. Now we are seeing the end result of these changes. Problem is these engines are engineered to last through the warranty period but what happens when you've tracked the car? Will they honor the warranty?
I can recall being at Tech Tactics in PA several years ago when the hydraulic followers on the 991.1 GT3RS engines were starting to fail. I spoke to several owners who had engines replaced and even one that had two engine replacements. However, I did speak to one guy who had been tracking his car hard and had no issues whatsoever. But he did state that the first thing he did was dump the Mobil 1 and put in a better oil and changed it after every track event. I know the DLC coating helps, but these components are operating in boundary layer lubrication, so oil quality makes a huge difference and added anti-wear additives or increased film strength goes a long way. That said, there is only so far coatings and lubricants can go if there is a manufacturing defect in the part or a design flaw.
Remember, back when API SL rated oils came out at the turn of the century we started seeing flat tappet cam engines lose lifters and camshaft lobes. Granted there were some junk lifters out there, but even high quality components were failed due to the reduction of ZDDP.
I can recall reading in the SAE magazine a few years back where Porsche was able to reduce the amount of aluminum they use by a few kilograms in these engine blocks. Now we are seeing the end result of these changes. Problem is these engines are engineered to last through the warranty period but what happens when you've tracked the car? Will they honor the warranty?
I can recall being at Tech Tactics in PA several years ago when the hydraulic followers on the 991.1 GT3RS engines were starting to fail. I spoke to several owners who had engines replaced and even one that had two engine replacements. However, I did speak to one guy who had been tracking his car hard and had no issues whatsoever. But he did state that the first thing he did was dump the Mobil 1 and put in a better oil and changed it after every track event. I know the DLC coating helps, but these components are operating in boundary layer lubrication, so oil quality makes a huge difference and added anti-wear additives or increased film strength goes a long way. That said, there is only so far coatings and lubricants can go if there is a manufacturing defect in the part or a design flaw.
Remember, back when API SL rated oils came out at the turn of the century we started seeing flat tappet cam engines lose lifters and camshaft lobes. Granted there were some junk lifters out there, but even high quality components were failed due to the reduction of ZDDP.
The following 5 users liked this post by Charles Navarro:
997 GT2 (01-05-2021),
DFI (04-02-2024),
johnsopa (06-09-2023),
pro1200 (12-04-2020),
s4corrado996tt (01-06-2021)
12-03-2020, 04:24 PM
#94
Racer
These cases are junk. They move all over the place. I just bought a new case for a customer whose block was cracked and we probed it. Bores and deck are all over the place. They run out of the box about .0007-.0008" total piston to cylinder clearance, but there were spots in the bore where there is negative clearance. That can't be good. Turn up the horsepower and we quickly find the weakest link as Neil has so kindly shared with us.
I can recall reading in the SAE magazine a few years back where Porsche was able to reduce the amount of aluminum they use by a few kilograms in these engine blocks. Now we are seeing the end result of these changes. Problem is these engines are engineered to last through the warranty period but what happens when you've tracked the car? Will they honor the warranty?
I can recall being at Tech Tactics in PA several years ago when the hydraulic followers on the 991.1 GT3RS engines were starting to fail. I spoke to several owners who had engines replaced and even one that had two engine replacements. However, I did speak to one guy who had been tracking his car hard and had no issues whatsoever. But he did state that the first thing he did was dump the Mobil 1 and put in a better oil and changed it after every track event. I know the DLC coating helps, but these components are operating in boundary layer lubrication, so oil quality makes a huge difference and added anti-wear additives or increased film strength goes a long way. That said, there is only so far coatings and lubricants can go if there is a manufacturing defect in the part or a design flaw.
Remember, back when API SL rated oils came out at the turn of the century we started seeing flat tappet cam engines lose lifters and camshaft lobes. Granted there were some junk lifters out there, but even high quality components were failed due to the reduction of ZDDP.
I can recall reading in the SAE magazine a few years back where Porsche was able to reduce the amount of aluminum they use by a few kilograms in these engine blocks. Now we are seeing the end result of these changes. Problem is these engines are engineered to last through the warranty period but what happens when you've tracked the car? Will they honor the warranty?
I can recall being at Tech Tactics in PA several years ago when the hydraulic followers on the 991.1 GT3RS engines were starting to fail. I spoke to several owners who had engines replaced and even one that had two engine replacements. However, I did speak to one guy who had been tracking his car hard and had no issues whatsoever. But he did state that the first thing he did was dump the Mobil 1 and put in a better oil and changed it after every track event. I know the DLC coating helps, but these components are operating in boundary layer lubrication, so oil quality makes a huge difference and added anti-wear additives or increased film strength goes a long way. That said, there is only so far coatings and lubricants can go if there is a manufacturing defect in the part or a design flaw.
Remember, back when API SL rated oils came out at the turn of the century we started seeing flat tappet cam engines lose lifters and camshaft lobes. Granted there were some junk lifters out there, but even high quality components were failed due to the reduction of ZDDP.
12-03-2020, 06:20 PM
#95
Are we talking about only .1 engines or .2 as well?
12-04-2020, 02:01 AM
#96
taormina racing is making high quality engine blocks for 964's. said he was moving on to water cooled at some point. prob just meant mezgers, but who knows, the demand might be there for 991 blocks too.
12-05-2020, 11:15 AM
#99
Rennlist Member
Not to take away from the purpose of this thread, all A40 oils are going to have similar formulation as required to meet the A40 approval. They use a standard additive package at a specified blend rate. There is very little wiggle room on formulation. The only thing they can do it play around with viscosity as there are acceptable ranges for each advertised weight, so some oils are formulated at the bottom end of the spec for improved viscosity.
12-05-2020, 03:27 PM
#100
01-05-2021, 04:33 PM
#102
https://www.motul.com/us/en-US/produ...ition-15w50--2
in my 928GTS i prefer the 300v 20W-60 LeMans Oil
https://www.motul.com/us/en-US/produ...-mans-20w60--2
just my 2 pence ;-) theses oils are top SPEED German Autobahn proof tested;-)
regards Klaus
Last edited by 997 GT2; 01-08-2021 at 03:16 AM.
The following 2 users liked this post by 997 GT2:
FogCitySF (01-05-2021),
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01-06-2021, 02:05 AM
#103
997 GT2! May I ask will 15W~50 thicker oil would take a lot more time for engine oil temp to warm up since the gap between mechanical parts of newer modern engines are very small. Thx!
Last edited by s4corrado996tt; 01-06-2021 at 02:09 AM.
01-06-2021, 05:05 PM
#104
Warming Up the engine is absolute normal and it takes me about 10 miles, but i dont Drive my toys below Zero degree Celsius during Winter times.
Afaik the 300V COMPETIION MOTUL has the double wheight bearing capacity until the oil Film breaks down under pressure compared to the Castrol Edge Oil.
as an further Goodie i add also 1 Bottle CERATEC Additive distributed by LIQUI MOLY.
CERATEC is an Emulsion of hexagonal Boriumnitrid to the engine oil.
CERATEC
regards Klaus
Last edited by 997 GT2; 01-08-2021 at 03:15 AM.
01-07-2021, 12:03 AM
#105
NOT at All.
Warming Up the engines is absolute normal and it takes me about 10 miles, but i dont Drive them below Zero degree Celsius during Winter times.
Afiak the 300V COMPETIION MOTUL has the double wheight bearing capacity until the oil Film breaks down compared to the Castrol Edge Oil.
as an further Goodie i add also 1 Bottle CERATEC Additive distributed Form LIQUI MOLY.
CERATEC is an Emulsion of hexagonal Boriumnitrid to the engine oil.
CERATEC
regards Klaus
Warming Up the engines is absolute normal and it takes me about 10 miles, but i dont Drive them below Zero degree Celsius during Winter times.
Afiak the 300V COMPETIION MOTUL has the double wheight bearing capacity until the oil Film breaks down compared to the Castrol Edge Oil.
as an further Goodie i add also 1 Bottle CERATEC Additive distributed Form LIQUI MOLY.
CERATEC is an Emulsion of hexagonal Boriumnitrid to the engine oil.
CERATEC
regards Klaus