Are DFI engines unreliable?
02-04-2016, 08:38 AM
#46
Clearly you're a hard core liberal, who likely believes in man made climate change. I'm curious how you justify tracking your car and spewing tons of CO2 into the atmosphere?
02-04-2016, 08:38 AM
#47
As the person who took that photo and then followed it over here, I will go on record saying i have ZERO concerns over the reliability of these motors. That carbon, while it may shock some and cause others to go off about how these motors need to be proven, is something we see all the time. The motor is apart because we have a stroker project in the works and we are doing R&D. Truth be told, if i knew the hysteria it would create, i would get back in the Delorean and head back to 12 hours ago and punch myself in the face.
That said, we probably don't hear much about it in the Porsche world, because people don't put the miles on these cars like they do in an Audi and BMW - which is where I first heard about this years ago.
DFI has significant advantages, but the carbon build up issue is very real. In my opinion, media blasting the intake is going to be part of routine maintenance every 30-50k miles. On a high performance engine, I don't think this expense is unreasonable. On a daily driver that puts on tons of miles - I would be annoyed greatly. One thing that concerns me is that the build up is slowly progressive and performance degradation will be same.
02-04-2016, 08:52 AM
#49
Nordschleife Master
Thread Starter
I have truly believed we can have an intelligent conversation about this subject. It was not my intention to involve other parties(which I obviously stupidly did) and cause problems.
Carbon buildup is not a cause of concern in Porsche DFI engines,as you've heard from people with a lot more experience than me.
I reserve my right to stand by my opinion and my opinion alone.
I am the moderator of this thread and may chose to close it if needed.
Carbon buildup is not a cause of concern in Porsche DFI engines,as you've heard from people with a lot more experience than me.
I reserve my right to stand by my opinion and my opinion alone.
I am the moderator of this thread and may chose to close it if needed.
02-04-2016, 09:23 AM
#50
Drifting
[QUOTE=Spyerx;12985997]Won't show in Oil Analysis. Have to look at the intake valves.
yes thanks , was posting that point in response to thread topic and engine wear/reliability
yes thanks , was posting that point in response to thread topic and engine wear/reliability
02-04-2016, 09:57 AM
#51
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Agree, regarding reliability.
That said, we probably don't hear much about it in the Porsche world, because people don't put the miles on these cars like they do in an Audi and BMW - which is where I first heard about this years ago.
DFI has significant advantages, but the carbon build up issue is very real. In my opinion, media blasting the intake is going to be part of routine maintenance every 30-50k miles. On a high performance engine, I don't think this expense is unreasonable. On a daily driver that puts on tons of miles - I would be annoyed greatly. One thing that concerns me is that the build up is slowly progressive and performance degradation will be same.
That said, we probably don't hear much about it in the Porsche world, because people don't put the miles on these cars like they do in an Audi and BMW - which is where I first heard about this years ago.
DFI has significant advantages, but the carbon build up issue is very real. In my opinion, media blasting the intake is going to be part of routine maintenance every 30-50k miles. On a high performance engine, I don't think this expense is unreasonable. On a daily driver that puts on tons of miles - I would be annoyed greatly. One thing that concerns me is that the build up is slowly progressive and performance degradation will be same.
02-04-2016, 09:59 AM
#52
Nordschleife Master
This is a well known issue for many other manufacturers. It is one of the challenges manufacturers have encountered since switching to direct injection. There is no turning back,but engineers are working on a solution as I and others have described in previous posts.
By posting this thread,I have not had the intention to create any sort of panic,I am actually quite surprised many are not aware of these problems for other manufacturers. Let's make it clear that for the moment,Porsche has not had any carbon build up issues with their direct injection engines. It is just a concern that it might manifest in the future. As I said,perhaps the boxer engine design is much better than the direct injection engines found in VW,Audi,BMW etc.
I was honestly hoping to turn this into a constructive discussion,nothing else. I am certainly not looking to turn this into name calling and pointing fingers. Please use your judgement and let's keep this discussion on point and civilized.
Thank you.
By posting this thread,I have not had the intention to create any sort of panic,I am actually quite surprised many are not aware of these problems for other manufacturers. Let's make it clear that for the moment,Porsche has not had any carbon build up issues with their direct injection engines. It is just a concern that it might manifest in the future. As I said,perhaps the boxer engine design is much better than the direct injection engines found in VW,Audi,BMW etc.
I was honestly hoping to turn this into a constructive discussion,nothing else. I am certainly not looking to turn this into name calling and pointing fingers. Please use your judgement and let's keep this discussion on point and civilized.
Thank you.
02-04-2016, 10:00 AM
#53
02-04-2016, 10:07 AM
#54
Nordschleife Master
As the person who took that photo and then followed it over here, I will go on record saying i have ZERO concerns over the reliability of these motors. That carbon, while it may shock some and cause others to go off about how these motors need to be proven, is something we see all the time. The motor is apart because we have a stroker project in the works and we are doing R&D. Truth be told, if i knew the hysteria it would create, i would get back in the Delorean and head back to 12 hours ago and punch myself in the face.
02-04-2016, 10:13 AM
#55
Rennlist Member
I share Nick's concerns, and also appreciate John's sensitive position.
As explained, the piston top fouling was from moving the car around the shop several times, which didn't allow the engine to come up to temperature and burn it off.
This would occur with any type of injection, and isn't permanent.
Intake area fouling with direct injection (from any manufacturer) is another issue, and it's not a question of if, but when.
It's a fact of life with PCV systems that can't attain 100% efficiency, aftermarket catch cans are better, but will only delay the inevitable.
I plan to add a vent to air intercept, not very environmentally friendly I know.
The latest V10 revision in the R8 uses both port and direct injection, problem solved.
As explained, the piston top fouling was from moving the car around the shop several times, which didn't allow the engine to come up to temperature and burn it off.
This would occur with any type of injection, and isn't permanent.
Intake area fouling with direct injection (from any manufacturer) is another issue, and it's not a question of if, but when.
It's a fact of life with PCV systems that can't attain 100% efficiency, aftermarket catch cans are better, but will only delay the inevitable.
I plan to add a vent to air intercept, not very environmentally friendly I know.
The latest V10 revision in the R8 uses both port and direct injection, problem solved.
02-04-2016, 10:30 AM
#56
Rennlist Member
As the person who took that photo and then followed it over here, I will go on record saying i have ZERO concerns over the reliability of these motors. That carbon, while it may shock some and cause others to go off about how these motors need to be proven, is something we see all the time. The motor is apart because we have a stroker project in the works and we are doing R&D. Truth be told, if i knew the hysteria it would create, i would get back in the Delorean and head back to 12 hours ago and punch myself in the face.
02-04-2016, 10:35 AM
#57
Drifting
02-04-2016, 10:45 AM
#58
Nordschleife Master
Originally Posted by BGB Motorsports
As the person who took that photo and then followed it over here, I will go on record saying i have ZERO concerns over the reliability of these motors. That carbon, while it may shock some and cause others to go off about how these motors need to be proven, is something we see all the time. The motor is apart because we have a stroker project in the works and we are doing R&D. Truth be told, if i knew the hysteria it would create, i would get back in the Delorean and head back to 12 hours ago and punch myself in the face.
02-04-2016, 10:47 AM
#59
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These are all good comments especially considering that at the end of the day, this forum is very useful for information that we otherwise wouldn't have if we all locked ourselves away in our shops or rooms and didn't share information. You guys are furthering the knowledge for yourselves and the rest of the world! I think that everyone is aware of the carbon buildup and the oil that gets on the backside of the valves. I have seen motors disassembled with 30K miles and they're caked. At the end of the day, i think that the concern should be towards trying to free up power via flow on the intake side. Do i have concerns of longevity though? NO! I think it's worth saying that everything can always be improved with hindsight and sure there are things we don't like about what the motors look like when opened, but the reliability of this motor vs. its predecessor is a huge success IMO. I'm not an engine builder nor am i an engineer or an expert; I am just fortunate to have been around these motors with a lot of miles and hours on them so i know firsthand what the weak points are for running time and if i thought anything we did had a shelf life to it, i would stop for fear of the repercussions down the road.
The DeLorean is perfect for something like this but lucky for you, there are 9 more times to prove yourself and i know that you will get that #38 to the top step sooner or later! I have faith in you bud, as do all of us here!
The DeLorean is perfect for something like this but lucky for you, there are 9 more times to prove yourself and i know that you will get that #38 to the top step sooner or later! I have faith in you bud, as do all of us here!
02-04-2016, 10:56 AM
#60
Rennlist Member
These are all good comments especially considering that at the end of the day, this forum is very useful for information that we otherwise wouldn't have if we all locked ourselves away in our shops or rooms and didn't share information. You guys are furthering the knowledge for yourselves and the rest of the world! I think that everyone is aware of the carbon buildup and the oil that gets on the backside of the valves. I have seen motors disassembled with 30K miles and they're caked. At the end of the day, i think that the concern should be towards trying to free up power via flow on the intake side. Do i have concerns of longevity though? NO! I think it's worth saying that everything can always be improved with hindsight and sure there are things we don't like about what the motors look like when opened, but the reliability of this motor vs. its predecessor is a huge success IMO. I'm not an engine builder nor am i an engineer or an expert; I am just fortunate to have been around these motors with a lot of miles and hours on them so i know firsthand what the weak points are for running time and if i thought anything we did had a shelf life to it, i would stop for fear of the repercussions down the road.