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Are you saying if I don't get A good quality catch can that maybe 50K miles I will probably need A valve job?
If you do not address the cause of the coking yes, by as little as 30k miles the valve guides are worn beyond acceptable tolerances. Easy to see as the very hard abrasive build up is cycled up into the guide and acts similar to "sand paper" when this occurs. As the guide is a bras alloy metal, and softer than the material of the valve stem, the guide wheres rapidly. Back in the 60's and 70's, before port fuel injection this was common on every engine due to the coking carbureted engines experienced. Our Federal Gov mandated all gasoline have minimal amounts of detergent additives in the fuel to combat this, and this helped at that time, and when port injection became common all intake valve deposits went away and until GDI this has not been an issue. Now, as no fuel can touch the backsides of the intake valves this is back far worse that ever before. It is impossible to not have this wear as you can see how this abrasion takes place in these pictures:
Note how this port injection LS engine with 142,000 miles has not a spec of deposits on it....this is due to how a port injection engine constantly sprays the intake valves keeping them clean and cool:
And this is why:
and look at how the valve stem where it cycles up into the guide draws these very hard abrasive deposits into the guide and also how the guide pushes them down the stem:
This because with GDI the fuel never touches the valve, and the temperature the valves now operate at are many times higher than when the fuel constantly cooled and cleaned them.:
So the wear is inevitable. If you want further proof, it only takes app 5-10 minutes and minimal tools to remove your intake manifold and closely inspect your own valves to see and document with pictures. Most all already know about the valve instability with the LS7 from a machining alignment error and how quickly they wear out in 5-10k miles as is documented in great detail in the tech sections and the class action suites pending. And that is with valves completely deposit free.
Have several threads on the intake valve coking issues with the LT4, so will make this one for the LT1.
This video does a good job of showing you what the issues are, the causes, and better understanding your new generation engine and how to prevent issues down the road. Look close and pause the video several times to see just how rapidly the intake valves are building the deposits.
I recommend the crushed walnut shell blasting media service but the manual cleaning as shown will also work.
Now, much of this is redundant if a member searches, but I will cover it all here for the C7 crowd in one thread.
Prior to 2014, all GM V8 gasoline engines were port injection. This constantly showered the intake valves with detergent fuel (ALL gasoline in the US must have minimum mandated detergent content to keep valves clean from back prior to port injection when carbureted engines experienced this coking causing wear to valve guides and stems resulting in a needed valve job by 40-50k miles) and when the industry migrated to the port fuel injection most have grown up with valve jobs went the way of the dinosaur, that is until GDI came onto the scene to be able to meet Federal emissions and CAFE fuel economy standards. So, here is a diagram of how a port injection fuel system kept your intake valves spotless longer than the life of the engine, and why most do not remember when a valve job was part of owning a car:
This fuel spray kept the valves cool and clean and even after 100-200k miles, a port injection engines intake valves will never have deposits on then, and therefore the valve guides and stems rarely saw wear (unless a machining error as the LS7 is known for in some instances) and the main reason for a "catchcan" was to stop the oil ingestion that caused detonation, clogged ringlands, and other issues, but never contributed to premature wear of internal engine parts and the degradation of power and economy over time like we see today with GDI.
Below shows how now, top tier fuel does nothing to improve any part of the injection or fuel system, and the fuel never touches the valves:
There are many advantages to GDI vs PFI, and this is mainly due to the near elimination of detonation (pre-ignition, Knock, etc.) as the fuel no longer is present through the entire intake and compression stroke where any glowing carbon spec or hot point in the combustion chamber could pre-ignite the A/F mixture. Now the fuel is not introduced until the final 10% or so of the compression stroke, and it is present only milliseconds (most of the combustion process occurs before the fuel can even touch the piston top) so we can now see far higher compression ratios, lower octane fuels, less emissions, and better fuel economy. The fuel injectors now operate at 2000 plus PSI vs the 45-55 of old PFI, so they cannot easily form ANY deposits. This renders any fuel additives, top tier fuels, etc. useless and a waste where they were of great benefit to the PFI engine.
The downside is with no fuel to keep the valves cool and deposits free, we now have a far greater issue that back in the 60's and 70's when carbureted engines had the coking and wear issues from it. AT least then some fuel cooled and cleaned/slowed deposits. Now there is zero.
So, a valve that would have looked like these pictures of a PFI engine at say 142000 miles (actual mileage of the LS engine in these pictures):
now will look like this in as little as 40k miles:
And the deposits are not like the soft carbon build up on piston tops of PFI, these are hard crystallized very abrasive deposits that are pulled into the guide with every cycle of the intake valve causing premature wear far greater that back in the carbureted days. Look close at how the stem suffers as these deposits wear on it, and the guide is the softer of the material:
These deposits are caused by more than just the oil mist present in the intake air charge, there is also several other damaging compounds that enter the crankcase as blow-by, and what you see is only part of the issue. Over time, as these hard abrasive pieces break loose, smaller ones can be forced between the piston and cylinder wall causing scouring and larger ones can get trapped between the valve and seat causing piston to valve contact and a bent valve or worse:
Look closely at the valve above, and you can see on the left portion of the stem where the tulip meets a large chunk broke off and caused the damage. The owner bringing the car in to the dealer they did diagnose it right away so a good amount of driving was done after this occurred and you can see the additional build-up over where the chunk broke off.
Now, anyone with a 2014 or 2015 LT1 have doubts this is occurring in your engine? It only takes 5-10 minutes and minimal tools to remove your intake manifold and look at YOUR valves up close and see the severity at the miles you have on yours.
Now, how to prevent this?
The "catchcans" of the past that worked well with a PFI engine, only trapped 15-50% or so of this oil mix that bakes onto the valves so they may slightly slow the coking, but will do little to stop it. You must use one of the very few that catch and trap 95-08% of this mix, and those are true air/oil separation devices. ColoradoSpeed and Elite Engineering having two of the most effective period currently on the market (extensive test results available to any that wish to see how the other "catchcans" stack up).
You must stop as much of this as possible.
Now, looking around I see several well intended solutions, that are not well thought out, and the most common is to delete the PCV system, and just rout your clean and dirty side lines into a tank with breather, or worse, open hoses near the ground (where one due to the Venturi effect will suck up dust and dirt directly into the tank and the engine).
The PCV system does far more than satisfy emissions. Back when the Fed mandated the PCV system in the mid 60's, it was rare for an engine to go much over 50k miles before excessive wear of all internal parts resulted in an entire rebuild being needed. And even though the PCV system was mandated for emissions alone (before that draft tubes were the norm, similar to the breathered Tanks seen today) but it did not take long for the industry to see these same engines were going 100-150k plus miles with little internal wear. Studying this found that the PCV system was constantly removing the damaging combustion by-products from the crankcase as soon as they entered and were still in a gaseous state. If allowed to settle, these mixed with the oil contaminating it and causing wear and failure eventually. The PCV system was removing these allowing the oil to stay cleaner longer, and the damaging compounds to accumulate at a minimal amount. So, defeating your PCV system is a sure way to cause a shortened engine life and accelerated wear. The compounds causing this wear and damage are as follows:
Water vapor
Unburnt fuel
Abrasive soot and carbon particles
Sulfuric acid, and more.
70% plus of internal engine wear is caused by the particles in the 2-5 micron size, and as your oil filter can only trap down to 15 microns in size, if these are allowed to accumulate in the engine oil and crankcase, you are drastically shortening the life of your engine. ANY defeat of any critical function of your PCV system is going to allow this, and/or worse. Allowing pressure to build and vent is also damaging over time to the rings, ringlands, and cylinder walls due to "ring flutter" and other damage caused by ring instability, so you want to pull vacuum/suction at all times, and NOT ever vent pressure as it must first build until it can vent, and no good comes from crankcase pressure.
So, the systems that deal with this properly are addressing the dirty, or foul side with a truly effective separation device, and w special separator that is used on the "clean, or fresh side" and add a secondary evacuation suction source for when the engine is under acceleration and no intake manifold vacuum is present.
I'll stop here for now and invite questions and discussion on the GDI engines in general, and more specific GM's and what they have done to reduce the ingestion, and why this affects EVERY single GDI engine made in the World from every auto maker. Understanding and making the correct emissions compliant, not effecting warranty changes to ensure you get the longest enjoyable life out of these awesome engines.
Here is my lt4 at over 10,000 miles pretty clean for a GDI!
No catch can. I'm not seeing a huge problem on mine!
My lt4 seems much better on oil use than the LT1 I had.
My C7 is my 2nd GDI engine, before all this I had an Excursion diesel, a person at Wal-mart out of the blue asked me if I was interested in selling my Excursion. Turns out he was REALLY serious & I made out really well. All except I was without a car. I had my heart set on a corvette but was a year too soon, so I looked around for the a cheap little sports car to tide me over until I could dealers started taking orders on the C7. I found a Hyundai Genesis Coupe that had a V6 GDi engine. This engine suffered from the same black tar crap on the valves as does the LT1. So I wound up ordering a Aquamist system but installed it in each runner (so 6 nozzles..) to get the max. cleaning effect. I had to order methonal mix by the case & additionally had to order straight methonal to increase my mix beyond 50/50 ratio. It got a little expensive but in the end it did finally keep the valves. I never really saw a increase in mileage due to it's use however I only ran it for about a year & then traded off.
Now with the LT1, I done 2 cleanings manually & a half cleaning with an intake system. Everyone has probably seen the pics. of the valves I cleaned, but here's the BG Products VIA or Vehicle Injection Apparatus. If you want to bring attention to yourself get one of these thing & a BG Products Direct Injection Cleaning Kit. The cleaning kit comes with 2 liquids one of which can be sprayed via the VIA (... hehe) into your intake. Fair warning though you will create a cloud of smoke so large the neighbor will think the city is on fire & that's within the first 5 minutes. I saw no improvement during the 5 minutes I used this BG setup nor could I imagine any city allowing this to take place anywhere. Search youtube for people trying these intake cleaning systems
Wormwood
Good info except the Ford Excursion gasoline engine never had GDI. Only the diesel like yours was, and DI in diesels is not as big of an issue as in gasoline engines. I assume you had the 7.3, and I kick myself for EVER selling mine. Loved it. In fact Ford has only used GDI on the ecoboost series of engines. No Ford V8 to current model year is GDI, but it is coming soon.
As for the upper induction cleaning, yes, you can effectively use a water injection system, but not as easy as stopping the deposits from forming to begin with, and no BG/Seafoam/CRC,etc. solvent can remove more than 50% of GDI backed on depoists (and yes, you are also correct the Genesis is GDI and they all have this issue).
A constant introduction as you show (thanks for the pictures, this lends a ton of credibility to your post, and you have a far better grasp than most do on GDI) will greatly slow the coking rate, but a boost engine is generally set to only spray when a pre-set controller senses "X" amount of boost, and then only during that short period and has little effect on slowing the deposits as most are not running boost 100% of the time at the level meth injection activates. And the cost and hassle is far greater than most are willing to go through when a simple system that stops it at the source is easily available and easy to install.
Now, back to using an upper induction solvent based cleaner. On a port injection engine these are beneficial is used rarely as the soft carbon that builds on the piston tops and inside the combustion chamber will be loosened and expelled harmlessly out the exhaust (mostly), but the deposits on a GDI engine are completely different and after time are baked to a crystallized very hard and abrasive coating, and at the rapid rate this builds, using a solvent cleaner (except at very low mileage when deposits are just starting and are still soft) will cause app. 5-% of these to expand and break loose. This is where the damage occurs (aside form the steady constant wear to the valve guides) as the smaller hard particles will scour/scratch the cylinder walls and pistons as this GM GDI piston here with very low miles, but a BG cleaning from the dealer shows:
And this valve shows where a chunk broke loose and was trapped between the valve and seat allowing the piston to make contact and bend the valve. As the dealer told the owner under warranty (we cannot find anything wrong" he drove it as you can see more deposits were building over where the chunk broke loose, until he insisted they do compression tests and found this:
(note the left portion of the tulip where the deposit broke loose)
So, excellent post wormwood! What you did to the Genesis is excellent work. I hope you can add more and that you understand why the solvent based upper induction cleanings are very risky for a GDI engine where for port injection they were beneficial.
Mike, can you pint out anywhere I made that claim? Intake valve coking in GDI engines is gradual, and most will still start even with serious blockage.
:
Originally Posted by coSPEED2
Intake valve guides will be long worn out of acceptable tolerances by 40k miles.
"Long worn out" meaning that a decent amount of coking as taken place before 40k miles. Ya maybe i was reaching little by stating 20k miles.
Although still with your logic most DI engines that have 40k miles will have mass amounts of carbon build up. Mass carbon build is will be noticeable at least to half the people driving. With millions of DI engines on the market. That means millions of people will start having real problems before warranty is over. We would hear a lot more about the problems of DI engines than we do. GM would be insane to offer 100k mile warranty on any DI engine. by 100k your car will not start.
I just feel if all DI engines were getting mass build up at 30-40k miles. We would simply hear more about it.
You really have a strong view point on this, i can respect that. But its time to start proving your points. Take pictures of LT1/LT4 engines that come by your shop. Stop posting pictures of BMW engines.
I have only seen one c7 corvette valve picture on this forum. that was from a LT4 with no carbon.
"Long worn out" meaning that a decent amount of coking as taken place before 40k miles. Ya maybe i was reaching little by stating 20k miles.
Although still with your logic most DI engines that have 40k miles will have mass amounts of carbon build up. Mass carbon build is will be noticeable at least to half the people driving. With millions of DI engines on the market. That means millions of people will start having real problems before warranty is over. We would hear a lot more about the problems of DI engines than we do. GM would be insane to offer 100k mile warranty on any DI engine. by 100k your car will not start.
I just feel if all DI engines were getting mass build up at 30-40k miles. We would simply hear more about it.
You really have a strong view point on this, i can respect that. But its time to start proving your points. Take pictures of LT1/LT4 engines that come by your shop. Stop posting pictures of BMW engines.
I have only seen one c7 corvette valve picture on this forum. that was from a LT4 with no carbon.
Mike, I answered your question where you and others said "we would all hear more about it" so I posted the different brands. All of those car makers were listed in that comment, so I posted pictures of them as well as the LT1's.
AI also have ported plenty of C7 corvettes and the same engine int he 2014 and up GM trucks. Maybe you missed those. Thats why if you have one, and are not running a good effective can, take the few minutes to remove your own intake manifold and share pictures with us.
Here again is probably the best, a complete video:
And further, the issues caused by the coking and excessive oil ingestion/consumption IS the #1 warranty related dealer visit, so I figure that counts more than the masses that just drive a car and never pay attention to anything under the hood. That is also why I posted the dyno graph compilation showing the steady degradation of power over a 3 year period, and how it was restored after a crushed walnut shell media blasting service.
What is it you would like to see? If your not wanting to discuss the technical details, and actual engines showing the coking (LT1 and other GDI, especially GM's) then that's fine as well. So far, I have not seen a single document from you showing otherwise, and that would be great for you to actually get involved. Drama and disruptions are what I would like to avoid, this is to be factual and document-able in what were discussing here. Your own LT1 engine would be a great example.
Oh, the LT4 example shows a good amount of buildup as I posted other LS valves from port injection engines showing zero deposits. The light colored coking clearly visible it the LT4 pic shows how the guide has been pushing the deposits down as the valves cycle and this is where the guide wear occurs. The color merely indicates how hot the LT4 valves operate. The hotter the lighter the deposit color.
Mike, I answered your question where you and others said "we would all hear more about it" so I posted the different brands. All of those car makers were listed in that comment, so I posted pictures of them as well as the LT1's.
AI also have ported plenty of C7 corvettes and the same engine int he 2014 and up GM trucks. Maybe you missed those. Thats why if you have one, and are not running a good effective can, take the few minutes to remove your own intake manifold and share pictures with us.
Here again is probably the best, a complete video:
And further, the issues caused by the coking and excessive oil ingestion/consumption IS the #1 warranty related dealer visit, so I figure that counts more than the masses that just drive a car and never pay attention to anything under the hood. That is also why I posted the dyno graph compilation showing the steady degradation of power over a 3 year period, and how it was restored after a crushed walnut shell media blasting service.
What is it you would like to see? If your not wanting to discuss the technical details, and actual engines showing the coking (LT1 and other GDI, especially GM's) then that's fine as well. So far, I have not seen a single document from you showing otherwise, and that would be great for you to actually get involved. Drama and disruptions are what I would like to avoid, this is to be factual and document-able in what were discussing here. Your own LT1 engine would be a great example.
Oh, the LT4 example shows a good amount of buildup as I posted other LS valves from port injection engines showing zero deposits. The light colored coking clearly visible it the LT4 pic shows how the guide has been pushing the deposits down as the valves cycle and this is where the guide wear occurs. The color merely indicates how hot the LT4 valves operate. The hotter the lighter the deposit color.
I am pretty good at understanding theory . But do not touch my own engine. Most I have ever done is install a intake. I have never even changed oil before. I was born in the 90s also. So I didn't grow up with a lot of machincal knowledge.
I look at the catch can install and it seems a bit much for me. I need a detail video how to remove the cover. Get me a video or make one. I will post pictures, and buy a can from you if I think it's needed. That's my deal .
I am pretty good at understanding theory . But do not touch my own engine. Most I have ever done is install a intake. I have never even changed oil before. I was born in the 90s also. So I didn't grow up with a lot of machincal knowledge.
I look at the catch can install and it seems a bit much for me. I need a detail video how to remove the cover. Get me a video or make one. I will post pictures, and buy a can from you if I think it's needed. That's my deal .
That video I posted of the 2014 with 5500 miles should show pretty good, and I hear you being born in the 90's. From the 80's on Auto Makers have strongly moved marketing away from buyers ever touching their cars mechanically, BMW and Mercedes don't even include oil or trans dipsticks anymore (dealer only can check fluid levels!) and Ford and Mopar rarely include trans dipsticks. If you watch sales adds, most emphasize no need to do any maintenance for 10k plus miles, etc. I was born in the 50's, so Grandfather and Father taught us all, girls or boy's to do own maintenance and always keep track of fluids. I went to work for GM in the 70's, and have worked for Automotive Engineering firms since and since 2008 the firm I work for has focused on emissions and PCV systems specifically on GDI engines (and some today have implemented the firms designs on current models).
My kids and Grand-kids are all taught the basics as well as I never want them "uninformed" and susceptible to a sales person's BS.
Stay tuned and maybe we can get more owners of LT1's to come in that will remove their intake manifold, inspect and post pictures for all. It only takes a few minutes and simple tools and many members on the forums are DIY people so let's hope. The more actual photos and proof members share, the more the observers wanting to learn can see actual results.
Thanks!
Originally Posted by savewave
If your posts are missing from this thread, it's because they were in conflict with site rules. Take the pissin' match offline.
Thank's Jim.
Had tried to and I always make sure to never break the rules and enter another vendors threads and attack them as happened here. I usually try to ignore this things, but here replied back in kind. The reason for the thread is discussing the unique issues with GDI and to get as many involved in discussions in a civil manner.
Well, I guess the sky is falling and all our DI engines are headed for an early grave.
Take a look at Car & Driver's Nov 2015 issue and their long term test of a 2015 6.2L GMC Denali. C&D isn't noted for babying it's test vehicles.
After 40K miles the test cars perfromance:
0-60 went from 6.5 sec to 5.9 sec
0-100 went from 16.2 to 15.4 sec
rolling start 5-60 from 6.8 sec to 6.6 sec
quarter mile time from 15.1 sec to 14.5 sec
Performance improved significantly over time/mileage
No unscheduled oil was added during the 40K miles
If the valves were so badly carboned up as is being suggested, the acceleration would have degraded not improved. I'm not worried about my C7. Don
A good hard broken in engine from the start should always make more power with properly seated rings.
And the Sky is not falling, no where do I state that. What I am sharing is what happens over time with all GDI, and that is why I posted the 3 years dyno testing as the valves coke and deposits build. As it is gradual, and most trade there vehicle before 40k miles, most will never be aware. But here where most members are looking for knowledge on this new for GM V8's technology, many here do want to know.
Would be great for them to remove the intake manifold and inspect and share what they find, and a brand new acceleration test VS one after good ring seating should always show improvement.
No catchcan on this car, just annual dyno's on the same dyno from same shop and then after the last dyno a crushed walnut shell cleaning and the results right after.
3 years of tracking the coking effects far more accurately than acceleration runs, but if your happy then you should not change a thing. It is your car to care for as you choose:
Here is a quote from TopSpeed on the LS7 valve issues and guide wear. Different cause (no coking on port injection engines) but the LS7 was out in production for 8 plus years and now many are finding this issue? SO putting trust in PR releases concerning issues is rarely wise:
You have asked a lot of questions and your answers to some of them are in the Valve Sticky Thread NHTSA: File a Complaint - Valve Guide Issue, also Hib Halverson has a Valve Guide thread that shows up if you do a search. In regard to your question about when it can happen; its all over the place; there have been cars with 4,000 miles on them with bad exhaust valve guides and there are cars that go 100K miles. I do not think there is any data on total percentage of LS7's that have catastrophic failures due to the valve guides being bad and the resulting "dropped" valve. You may see some speculative percentages, based on what goes on in this Forum but that is it. No good answer except all LS7's are suspect in regard to excessive valve guide wear, IMO.
And I thought I would also share industry actions on this issue so any that doubt the severity and how hard all are working toward solutions realize what is going on behind the scenes....as to date, no automaker will acknowledge this publicly:
View Classroom Training by: Date | Technical Interest
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Gasoline Direct Injection (GDI) Engines
Available as open enrollment Seminar Available for On-site Delivery Part of an SAE Certificate Program
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I.D.# C1009 Printable Description
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The quest for more efficient, smarter, and environmentally cleaner liquid-fueled spark ignition (SI) reciprocating engines is more alive and intense now than ever before. GDI SI engines have overcome many of the original limitations and are now becoming commonplace. This seminar will provide a comprehensive overview of GDI engines. Mixture preparation and the combustion process, with an emphasis on strategies for both homogenous and stratified charge operation and control, including issues related to the direct injection of gasoline into the combustion chamber, and fuel injection system requirements for optimal spray characteristics will be explored. Emission of pollutants, fuel economy and effects of some key design and operating parameters will also be covered. The seminar concludes with an overview of a select list of production and prototype GDI engines.
Learning Objectives
Upon completion of this seminar, you will be able to:
Describe the rationale behind the GDI engine operation
Analyze the important processes in GDI engines
Explain liquid atomization, sprays, and injector requirements for successful GDI operation
Utilize the technology and the logic behind gasoline direct injection
Estimate and predict effects of key engine design and operating conditions on performance, combustion, and emission in GDI engines
Communicate effectively with engineers working on fuel injection, combustion and emission aspects of the GDI engine in your firm or with customers
Effectively contribute to the design of critical components such as combustion chambers, injectors, and emission reduction strategies
Explain and utilize trade-offs between increasing engine performance and maintaining low emission characteristics
Who Should Attend
This seminar will be especially valuable for engineers, technical and project managers, researchers, and academicians. Engineers working on the design of components for high efficiency and performance of GDI engines as well as those directly and indirectly involved in mixture preparation and emission reduction of harmful pollutants from these engines will highly benefit from this course. Environmental engineers desiring to expand their understanding of fuel spray formation, combustion and emissions from GDI engines will benefit, as well as, engineers active in the development and application of software for the modeling and design of combustion chambers, fuel spray dynamics, combustion and emission issues.
Prerequisites
Attendees should have general knowledge of engine operation especially in-cylinder combustion processes. However, a very concise review of the subject is presented.
Topical Outline
DAY ONE
Combustion Systems
Relative position of spark plug and fuel injector
How to achieve homogeneous and stratified charge -- spray-, wall-, and air-guided combustion systems
Fuel Injection System
Fuel injection system requirements
Fuel injector requirements and classification
Fuel Spray Characteristics
Spray atomization requirements
Sac spray consideration
After-injection
Fuel spray penetration and cone angle
Split injection
Sprays characteristics of injectors
Effects of ambient pressure (density) on spray
Spray characterization (GDI)
DAY TWO
Mixture Formation
In-cylinder flow characteristics and GDI combustion
Fuel-air mixing process
Spray-wall interactions
Cold start and wall wetting issues
Combustion Process and Control Strategies
Engine Operating Modes and Fuel Injection Strategies
Early-injection, late-injection, stoichiometric operation
Operating mode transition
Split Injection Strategy
Two-stage, split, and post injection
Combustion characteristics
Homogeneous-charge and stratified-charge combustion
Effects of Engine Operating and Design Parameters on GDI Combustion
Injection and ignition timings
Spray cone angle
EGR
Knock resistance characteristics
Air-assisted versus single-fluid GDI fuel system
Injector, Combustion Chamber, and Intake Valve Deposits
DAY THREE
Emissions of Pollutants - Reduction Approaches
Hydrocarbon, NOx, particulate and noise emissions
Fuel Economy
Factors affecting improved fuel economy
Fuel economy versus emissions compromise
Select Gasoline Direct-Injection Engines
Early DISC engine
Mitsubishi reverse-tumble-based wall-guided
Concise review of Toyota, Nissan swirl-based (wall-guided), Audi wall-guided, AVL, FEV air-guided, Ford, Honda spray-guided, Isuzu, Mazda swirl-based, wall-guided, Mercedes-Benz spray-guided, Ricardo tumble-based, wall-guided, Volkswagen tumble-based, wall-guided FSI
GDI Fuel Rail Technology
Benefits of Turbocharging a GDI engine
Instructor(s): Bruce Chehroudi
b_chehroudi" Dr. Chehroudi is Chief Scientist and Group Leader at Advanced Technology Consultants. His previous positions include: Principal Scientist at Air Force Research Laboratory (AFRL/ERC), Chief Scientist at Raytheon STX (formerly Hughes Aircraft STX), Professor of Mechanical Engineering, and Research Staff Member at Princeton University. He specializes in fluid mechanics and heat transfer, laser optical diagnostics, internal combustion engine, gas turbine and rocket engines, structure of sprays, gas turbine engines, combustion, fuel injection issues and emission of pollutants. Dr. Chehroudi is an AIAA Associate Fellow, a member of Ta Beta Pi and the recipient of several SAE awards including the Arch T. Colwell Merit Award, the Ralph R. Teetor Award, the SAE Recognition Award and the SAE Forest R. McFarland Award in recognition of his efforts and leadership in contributions to the Continuing Professional Development Seminars. He has taught courses in the areas of internal combustion engines, thermodynamics, thermophysics of gas flows, combustion, and measurement system, and has more than 150 publications and over 200 presentations in conferences, national and international journals. Dr. Chehroudi has a Ph.D from Princeton University.
Fees: $1685.00 ; SAE Members: $1348.00 - $1517.00
To Register in RMBs for the 2015 Offering in China
Contact: Rick ****
SAE International China Office
Phone: +86 21-6131-2392; Fax: +86 21-2302-5988 E-mail: rickwang@sae.org
(Please note, to register in RMBs you must contact the SAE China Office.)
The offering of this seminar in Shanghai, China, is also applicable for 4.0 (or 2.0) Shanghai CEUs. You must complete all course contact hours and successfully pass the learning assessment to obtain CEUs.
And I thought I would also share industry actions on this issue so any that doubt the severity and how hard all are working toward solutions realize what is going on behind the scenes....as to date, no automaker will acknowledge this publicly:
[/B][/I]
What did you see in the detailed agenda that emphasizes coking or valve guide issues, neither of which are mentioned? The closest mention is at the end of day two, "intake valve deposits". Are you reading between the lines?
What did you see in the detailed agenda that emphasizes coking or valve guide issues, neither of which are mentioned? The closest mention is at the end of day two, "intake valve deposits". Are you reading between the lines?
Each of these subjects are in the training and R&D to reduce the coking issue. That is a good part of this training and certification class. Most is with different spray types, combustion chamber designs, multiple fueling events, etc. but the main topic is all related to the coking ( I am an Automotive Engineer and a member in good standing of SAE and when ever there is a topic on the issues with GDI I am notified and am part of the discussion groups. I can see how to a layperson how you could read it that way though.
Originally Posted by 2014C7
Well I would say if you got a good quality Ferrari you'd need one at 50k
Ferrari has really good air/oil separating systems on the new engines that require regular visits to the dealer for service as do most "super cars". Very few new Super Car owners do their own maintenance, so they are dealing with it far better than most. But a visit to the Ferrari Forums will show many threads on the intake valve coking issues in models prior to the last few years that did not. Google search, FerrariChat is a good one. They always have been, and still are an expensive car to have maintained.
Originally Posted by 2014C7
What strikes me is why I would want a tech to open up my factory sealed motor and spray walnut shells on the valves.
So the GM engineering team knows less than the people making the cans?Not at all. The engineers at GM that do the work (not the PR talking heads that give the interviews) are among the best in the world, and are very aware of every aspect of this. In fact one of the biggest budgets is for finding a solution that does not require user/owner maintenance. 99.9% plus of all owners of GDI vehicles are not aware of the issues, and all automakers want it to stay that way.
There are no "factory seals" on any GM production engine, and the crushed walnut shell service is endorsed by Audi, VW, BMW, and more. Just none of the big 3 yet as it is not known widespread yet and few service centers have the equipment. Done correctly, there is zero chance of any damage occurring unlike the solvent based ineffective upper induction cleaning's most domestic dealers push due to the high profit margin that can and does cause damage.
No offense but I will wait until mine gets low on power or blows up before disassembling the engine.
5 year warranty Probably should get me through to the C8 just fine.
Or worse case it blows up. Or I put some kit on and or trust a tech to tear into my vette...
yeah um works good now.
No offense intended just being direct and trying to make a joke or two.
And your probably like most. The mindset is all cars, no matter if mass produced or hand built are automatically assumed to be the best possible engineering when released to production and sales, yet that is so far from the reality as anyone with a close enough friend that is an engineer at any of the big 3 will tell you the most frustrating part of their job is to submit great ideas and solutions to improve or correct an issue and it is shot down by budget/legal/marketing/ or management.
Just ask the mid-low level engineers they canned for the ignition switch debacle after app 10 years of those same engineers pushing to be allowed to implement a less than .50 cent fix. Not a SINGLE upper management or top engineer was disciplined. But they did sacrifice those that did speak up to fix this years ago, and now it cost GM hundreds of millions.
So I totally understand your thinking. It is the most common out there, and the fact is most owners of GDI vehicles will have long since traded them for a newer model before the issues are severe enough to really be noticed by the average consumer. So great post!!
Also when the surface are freshly machines the engine built in a very clean room all bolts on cover torqued at once etc...that's what I mean by factory seal.
I was a wrench for a few years and still do so for a hobby. Splitting cases on a bike or a car engine is never the same as it was first assembled.
That's my honest opinion. I have the t-shirt on that.
Thanks I liked yours too. So the walnuts yeah "done correctly" that's the key.
So my Friend is a 30 year Ferrai now Ferrari/Porsche tech.
30k valve jobs are not uncommon in pre gdi Ferraris trust me on that.
so it was a joke.
I think that while your points are valid, if what you say is try than GM has a serious warranty future looming.
Cheers!!
Oh yeah! Have done many a belt service on the 308-328's and it is not easy, and you are dead on with the fist years of their GDI (have not seen many 2014 and up's with that many miles yet to see how well they are doing, but your buddy could share a ton of good info with us all as he has dealt with it far longer than the GM techs.)
I love Ferrari's, but dollar for dollar still would take a C7 for practicality and low cost of ownership!
Oh yeah! Have done many a belt service on the 308-328's and it is not easy, and you are dead on with the fist years of their GDI (have not seen many 2014 and up's with that many miles yet to see how well they are doing, but your buddy could share a ton of good info with us all as he has dealt with it far longer than the GM techs.) I love Ferrari's, but dollar for dollar still would take a C7 for practicality and low cost of ownership!
That's what my friend says too.
I'd take a 60's V-12 any day but finding one that can be had for what I am willing to spend is not an option anymore.
A teterossa would be cool maybe too.
The Corvette is like comparing apples and oranges to a Ferrari. And will outperform most Ferraris.
I own a Vette as I have not quite gotten to Ferrari ownership in allocation of resources to my car habit and truthfully The Zo6 is so fun. Period.
10-03-2015, 12:53 PM
