997.2 3.8 Engine Failure
02-08-2019, 08:55 PM
#346
02-10-2019, 02:27 PM
#347
Team Owner
I'd just like to say I read everything Jake is kind enough to bother putting up. I'm also on your email list and read about all the classes offered. I am truly tempted to spend the $ and time to attend but I'm retired, it's just a hobby, I'm 70 and don't need to take up the space. I've been a Porsche guy most my life. My life long best bud and his dad before him were Porsche techs. My last build was my 951 and before that many years ago a 2.7 we put in a 914, all with buds help. He too is retired now. Only does 3.2 and earlier and transmissions for friends, maybe. When you retire Jake Porsche will loose a super resource. What you do adds to the marque as much as the factory guys over the years. I'll stop with I do have a 997.2 S and truly hope we never met in person!
I sold the business when I retired. The company was a family deal 59 years old. I appreciate your business model. It is your love as much as the work you turn out. A company is an extension of yourself until it isn't. We sold to a bunch of young hot MBA guys. Due to my older brother health and my age needed to happen, but not the same company. Hope you have an able #2 to carry on what you have started.
I sold the business when I retired. The company was a family deal 59 years old. I appreciate your business model. It is your love as much as the work you turn out. A company is an extension of yourself until it isn't. We sold to a bunch of young hot MBA guys. Due to my older brother health and my age needed to happen, but not the same company. Hope you have an able #2 to carry on what you have started.
02-10-2019, 04:04 PM
#348
Three Wheelin'
I have taught some of those "artsy-fartsy" types at a few "prestigious" colleges. When I mention the words "strong work ethic" some of them look at me like a deer in headlights about to get hit by a mac truck. Yet out of every class there are a "few" who have the real potential to make it. One of the first questions I get is "what's the fastest way to become successful?"... My response.... "Well, the first one to do a specific task correctly... and do it correctly 1000 times will be much closer to success than the person who has done it only 10 times correctly." Again... deer in headlights. Then I say... "The person who has done it 20 years and 10,000 times is probably even better then the person with 1,000 times under his belt." Now the realization sinks in... To be successful takes a heck of a lot of work, proper training, repetition, and determination to do it correctly. I totally understand that the hardest aspect of building a team is finding high quality people with high standards, wisdom, and strong work ethics. They are hard to come by.
02-11-2019, 02:01 PM
#349
Former Vendor
Ok guys..
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
The following users liked this post:
mp2day (01-12-2020)
02-11-2019, 02:32 PM
#350
RL Community Team
Rennlist Member
Rennlist Member
Ok guys..
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
https://youtu.be/02HxKanh-JY
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
https://youtu.be/02HxKanh-JY
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
Does that same thing happen on the non-DFI motor crankshaft bearings as well, and if not, why is it different?
What allows the piston damage to only occur on the sides of the piston and not in the middle?
02-11-2019, 02:33 PM
#351
Ok guys..
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
Here’s the video of the teardown. Excuse my video skills, thats the best l can do with an iPad :-)
l have measured everything up, and the remainder of the internals are very good.
We are well underways with the reconstruction of the engine, the block is on the way to LN as of today.
02-11-2019, 02:45 PM
#352
Former Vendor
Jake, nothing wrong with those videography skills. Thanks much for the info and education. How much life would you say those crankshaft bearings had left in them and will those first 2 layers worn away shown the metals of a UOA?
Does that same thing happen on the non-DFI motor crankshaft bearings as well, and if not, why is it different?
Does that same thing happen on the non-DFI motor crankshaft bearings as well, and if not, why is it different?
The wear you see here likely happened in the forst 3-4 years of this engine’s life. It probably was present in the UOA at that time, but there are no results of that. The UOA results that Bronz has show elevated aluminum, but who is to say how much of that was the rod bearings, and how much was the worn piston/ cylinder material.
LSPI is a big problem that most people outside of engine circles have not heard about yet. For the last 4-5 years Lake Speed has been working with the Oak Ridge National Laboratories to better understand this, and we have contributed as well. These rod bearings will be heading to Oak Ridge for evaluation.
DI promotes much higher cylinder pressures, and therefore a formulation of the engine oil, with some elements being changed is warranted. When DI engines debuted, a change in the oil to promote the DI, and resist LSPI did NOT occur. The oil is way behind the engines, even though Lake and our team started working on this first. Over time, what we believed would happen, has happened, though it has not lead to widespread issues, or direct failures at this point. The PWM oil pump is able to throttle up and provide higher oil pressure on demand, which masks this effect a great deal. At the end of the day, it is still wear, and thats a lot for 76k miles.
The prior owner probably thought he was doing everything right, servicing by the book, and folowing the factory fill recommenations for oil (Mobil 1). Remember, when the owner’s manual was written, everything was a projection, the car had little to no time in service. That chapter needs to be rewritten.
At this point, a car like Bronz’s has a decade of use, so starting to change things around to give it a better life is arguably worth it.
02-11-2019, 02:56 PM
#353
RL Community Team
Rennlist Member
Rennlist Member
This particular wear is only seen with DI engines on the street. Track M96,97 engines can see this, but it’s usually from cooking the oil, causing thermal breakdwon, and loss of viscosity.
The wear you see here likely happened in the forst 3-4 years of this engine’s life. It probably was present in the UOA at that time, but there are no results of that. The UOA results that Bronz has show elevated aluminum, but who is to say how much of that was the rod bearings, and how much was the worn piston/ cylinder material.
LSPI is a big problem that most people outside of engine circles have not heard about yet. For the last 4-5 years Lake Speed has been working with the Oak Ridge National Laboratories to better understand this, and we have contributed as well. These rod bearings will be heading to Oak Ridge for evaluation.
DI promotes much higher cylinder pressures, and therefore a formulation of the engine oil, with some elements being changed is warranted. When DI engines debuted, a change in the oil to promote the DI, and resist LSPI did NOT occur. The oil is way behind the engines, even though Lake and our team started working on this first. Over time, what we believed would happen, has happened, though it has not lead to widespread issues, or direct failures at this point. The PWM oil pump is able to throttle up and provide higher oil pressure on demand, which masks this effect a great deal. At the end of the day, it is still wear, and thats a lot for 76k miles.
The prior owner probably thought he was doing everything right, servicing by the book, and folowing the factory fill recommenations for oil (Mobil 1). Remember, when the owner’s manual was written, everything was a projection, the car had little to no time in service. That chapter needs to be rewritten.
At this point, a car like Bronz’s has a decade of use, so starting to change things around to give it a better life is arguably worth it.
For those of you that don't know, Lake Speed is with Driven oils.
02-11-2019, 03:37 PM
#355
Instructor
Jake, thank you for educating us and sharing your experiences with the broad group. Your video was perfect. I'm a little confused as to why the piston skirt was rubbing against the cylinder wall. Isn't the piston ring designed to be the only metal that should actually touch the cylinder wall (with oil)? That skirt made a lot of contact.
02-11-2019, 04:15 PM
#356
lower rpms, lots of highway miles contributes to longevity. Diesel service is not cheap either. I've a friend that owns several delivery vehicles using big American V8 engines, with lots of highway miles and less stop and go and heat cycles, operating at lower average rpm, and he gets 300k+ miles from engines more often than not.
02-11-2019, 04:25 PM
#357
Former Vendor
Jake, thank you for educating us and sharing your experiences with the broad group. Your video was perfect. I'm a little confused as to why the piston skirt was rubbing against the cylinder wall. Isn't the piston ring designed to be the only metal that should actually touch the cylinder wall (with oil)? That skirt made a lot of contact.
There’s lots of variables that can lead to this, and l want to get some results back before spilling any of that info here.
Diesel engines see a different type of wear, and they have massive bearings to spread the unit pressure over the bearing surface. They are designed for cylinder pressures, and that’s why they use Diesel oils. Further, they have a redline of less than 3,000 RPM, as a general rule. The lower RPM is a big plus for longevity. There’s more to it than this, Lake and l plan to shoot a Rennvision video on LSPI next week.
The DI40 oil, and DT40 oil share no properties outside of viscosity, totally different formulations.
02-11-2019, 04:49 PM
#358
Drifting
Yeah, I'm confused about the skirt wear as well, especially after Jake said they'd never seen that failure before. In a typical engine the piston skirt isn't supposed to rub against the bore, but even when it does, the contact is almost ALWAYS on the sides perpendicular to the axis of the wrist pin.
For the skirt to wear where it did, I wonder if the piston was defective, perhaps warped. We didn't see the wrist pin or a close up of the connecting rod for that cylinder. Maybe the rod wasn't perfectly true or the bore for the wrist pin was bored off-axis?
I am very curious about this one.
I also am curious about what my main bearings look like, after seeing Bronz' bearings. I have about the same miles as he does. Maybe it's time for me to switch oils!
For the skirt to wear where it did, I wonder if the piston was defective, perhaps warped. We didn't see the wrist pin or a close up of the connecting rod for that cylinder. Maybe the rod wasn't perfectly true or the bore for the wrist pin was bored off-axis?
I am very curious about this one.
I also am curious about what my main bearings look like, after seeing Bronz' bearings. I have about the same miles as he does. Maybe it's time for me to switch oils!
02-11-2019, 05:00 PM
#360
Former Vendor
Yeah, I'm confused about the skirt wear as well, especially after Jake said they'd never seen that failure before. In a typical engine the piston skirt isn't supposed to rub against the bore, but even when it does, the contact is almost ALWAYS on the sides perpendicular to the axis of the wrist pin.
For the skirt to wear where it did, I wonder if the piston was defective, perhaps warped. We didn't see the wrist pin or a close up of the connecting rod for that cylinder. Maybe the rod wasn't perfectly true or the bore for the wrist pin was bored off-axis?
I am very curious about this one.
I also am curious about what my main bearings look like, after seeing Bronz' bearings. I have about the same miles as he does. Maybe it's time for me to switch oils!
For the skirt to wear where it did, I wonder if the piston was defective, perhaps warped. We didn't see the wrist pin or a close up of the connecting rod for that cylinder. Maybe the rod wasn't perfectly true or the bore for the wrist pin was bored off-axis?
I am very curious about this one.
I also am curious about what my main bearings look like, after seeing Bronz' bearings. I have about the same miles as he does. Maybe it's time for me to switch oils!
This wear made the sound the engine was making much deeper than a normal scored cylinder. That’s what fooled me in Bronz’s initial video, but it didn’t fool me with the stethoscope when the car arrived. l knew it as soon as l threw the sthethoscope into the mix, and listened to cylinder 1. l could also tell it from the rough running index for cylinder 1. It was so bad that cylinder 2 was even picking up some of the interference from it.
We may have a scenario here where a component was mis- machined at the factory, but we will never know now, since the dimensions are destroyed. The other pistons look fine. Thats the norm for bore scoring, though.. Usually just one cylinder sees all the damage, but sometimes its all 6.
To be clear, the worn bearings are concting rod bearings. The main bearings look fine. They do not see the effects of LSPI like the rod bearings do.
Don’t go freaking out. The cars have been driven enough that no matter what you can’t reverse what has already happened. This is the first time that l have ever shared any of the findings of LSPI in these engines, so please don’t make me regret it.
No, you have never heard of it before. Lots of things go on behind the scenes that you’ll never know. Its my job to find it, before it finds you.