New LT1 for 2014 6.2l alum block
#341
The thing that I don't get is there is a certain energy density for each substance. E-85 has less (~25.65 MJ/L) and Gasoline has more (~34.2 MJ/L). Thus, in a given system it takes more E-85 to produce the same amount of energy as gasoline. To keep up with this delta, some of the other chemical properties have to be used to make up the delta (that's why E-85 can tolerate higher compression). Consider:
Properties Ethyl Alcohol Gasoline
Boiling Pt 78.3°C 38.9°C
Flash Pt 12.8°C -42.8°C
Lower Explosive Limit 3.30% 1.40%
Upper Explosive Limit 19% 7.60%
For a given system, changing fuels will have a significant impact on the overall system. For E-85, you have to worry about how it reacts with fuel system components, how it absorbs water, etc.
One such change is that the fuel system will need to flow a significant higher quantity of E-85 to produce the same amount of HP. If you don't believe me, look at Weldon or any other fuel pump manufacturer's website.
As I read it, BG asserts that E-85 is some magical elixir that will make this engine awesome and the fuel system can keep up. The challenge I see is that GM already produces flex-fuel vehicles, all at a lower HP rating (no where near LS9 levels). To produce such a car, all of the fuel system would need to be significantly upgraded to flow sufficient fuel. It's basic physics.
Whenever one creates a vehicle, everything is a trade. Size, weight, power and cost (SWAP-C) is typically the quality factors that must be contented with in order to produce a product customers will buy at a specific price point. Add in more size, you have more aerodynamic drag and more weight, thus you will consume more fuel to move the vehicle. Add support for E-85 and you add sensors (to detect the type of fuel), larger fuel lines, bigger pumps, etc.
The other challenge is government regulations. Navistar has closed up shop because they cannot produce a diesel engine that meets federal emissions standards. GM has federal emissions standards they must meet as well. Also consider the CAFE requirements, where in 2025 we are looking at 61MPG for passenger cars. Given this is a brand new, clean sheet design that is to come in 2014 time frame, this engine will be significantly impacted by these regulations.
So, either GM has come up with something very new in the market place (i.e. it runs on puppy dog kisses), they have increased the cost of the vehicle or they have removed content.
For removal of content, see what happened to Chrysler in the later 1990s when they did that to most of their vehicles. It was bad enough where one of the guys I know ended up running a FEA model on the aluminum part that connects the tumbler to the ignition switch so they can make the metal as thin as possible yet last to just beyond the warranty period.
For new content, VVT, DI and other such tech has been on the market for quite some time. It is nice that GM is finally catching up, but it is a known commodity.
Thus my assertion that BG is more of a management person. If he is an engineer, he would have brought more meat to the table verses something that, frankly, could be found with Google and stated with a bit of bravado.
The other point I would like to make is that, when someone is setting up an architecture for a system, they define specific key quality attributes. These attributes drive how the different trades will be weighted and have a significant impact of how the system comes together. The area where the aftermarket comes in is when the end user / customer wants to impact these quality attributes. For example, they sacrifice fuel economy for better performance, because the use case of the vehicle is more for racing. Or they install a better audio system because they want a better driving experience. Bottom line is that the priorities the owner has are different than what the engineering community came up with and the aftermarket fills this gap.
In the aftermarket, there are some people who are highly skilled at what they do. Consider Tom Nelson of NRE, Smokey Yunick and so on -- all highly talented and knowledgeable. There are many folks who will pick apart the vehicle and will find ways to force the quality attributes one way or the other.
Last edited by out2kayak; 12-01-2012 at 07:36 PM.
#342
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#344
Answering this question would surely blow my alias. Please understand I am not at liberty to reveal that type of information. The information I have given you is a 100% accurate from the beginning of this thread and even now.
Bigg Gunz
Bigg Gunz
#345
A couple of questions if I may,
Forged cranks are great, but the PM rods don't appear to be much beefier. Have the PM rods not always been a weak link?
The Powder Metal Rods in this engine are better in many ways. However logically speaking, I was all for aircraft quality grade metal in Rods for many reasons.
Will the other Gen3/4 engine displacements be carried into the Gen5 power train lineup or will they be resized around the new head design? Yes, only one will pertaining to displacement. And that head design will be slightly different than the 2014 LT1.
Nobody has thought to ask about the 3 valve OHV design that was rumored. Is it completely off the table again? How did it perform? No
I own an iron block Gen4 5.3 which you suggested was begging for a combustions engineers touch with a poor boy budget. Educate me, I'm all ears. The 5.3 is a great platform and I am able to use my expertise to help you without bounds. So if you would please tell me what you are trying to achieve so that I may help you anyway possible in combustion knowledge. What upgrades if any have you done?
The LY6 still has secrets? Tell me more.
If and when the aftermarket decides to master this engine. It will surely become a hit with gear heads. However there are areas that I am restricted from putting forth proprietary information. As I've stated before this engine is only lacking 2 developments in the aftermarket. I would like to see someone take on the challenge and real develop them. VVT is not going away the aftermarket has to come forward with the technology, people, and tools sooner rather than later.
I AM GENUINELY CURIOUS, how did you get selected as our GM rep? Does GM give you a script response or just a general guide to what should be said? Did you request it or was everybody told simultaneously they could stir the pot so long as they didn't cross the line? I find this method of communication with a customer base to be fascinating.
Forged cranks are great, but the PM rods don't appear to be much beefier. Have the PM rods not always been a weak link?
The Powder Metal Rods in this engine are better in many ways. However logically speaking, I was all for aircraft quality grade metal in Rods for many reasons.
Will the other Gen3/4 engine displacements be carried into the Gen5 power train lineup or will they be resized around the new head design? Yes, only one will pertaining to displacement. And that head design will be slightly different than the 2014 LT1.
Nobody has thought to ask about the 3 valve OHV design that was rumored. Is it completely off the table again? How did it perform? No
I own an iron block Gen4 5.3 which you suggested was begging for a combustions engineers touch with a poor boy budget. Educate me, I'm all ears. The 5.3 is a great platform and I am able to use my expertise to help you without bounds. So if you would please tell me what you are trying to achieve so that I may help you anyway possible in combustion knowledge. What upgrades if any have you done?
The LY6 still has secrets? Tell me more.
If and when the aftermarket decides to master this engine. It will surely become a hit with gear heads. However there are areas that I am restricted from putting forth proprietary information. As I've stated before this engine is only lacking 2 developments in the aftermarket. I would like to see someone take on the challenge and real develop them. VVT is not going away the aftermarket has to come forward with the technology, people, and tools sooner rather than later.
I AM GENUINELY CURIOUS, how did you get selected as our GM rep? Does GM give you a script response or just a general guide to what should be said? Did you request it or was everybody told simultaneously they could stir the pot so long as they didn't cross the line? I find this method of communication with a customer base to be fascinating.
Bigg Gunz
#347
Well I'm most certainly flattered, I have to say I am not a GM Rep. What I am is a "Advanced Combustion Engineer" from somewhere within GM. I am here for one reason only as directed, and that was to reassure what is happening with the 2014 LT1. I do NOT engaged critics or those beyond reasonable thought. Yes, I have strict limits on what I can & cannot say. If I encounter a grey area on releasing information. I must report back for a GO or no GO. I can say with confidence one thing, everything that I have stated in this thread is 100% accurate. This particular thread is monitored extensive by someone high within GM, as I've walked a very fine line. Anything negative or lashing out due to speculation is removed from my report as this is unhealthy in our focus groups and brain storming secession. However anything that is of substance or real concerns by true gear heads on here, is address in our meetings. Then its voted on by engineers and if it requires action, then we are green lighted for developing what is needed if it is needed. It is not real time however it less than 3 weeks for a model or simulation. I and others are placed on this site for various reasons and the information from true gear heads with integrity and courtesy is invaluable to developing a well received product. I just decided to log in.
Bigg Gunz
Bigg Gunz
I thought of one more for you. What about correcting the speedo for gear swaps, will that be possible with these new E92 equipped cars?
Last edited by Robert91RS; 12-03-2012 at 03:47 PM.
#348
So, if we assume 125.7 lbs/hr @ 1450 psi then scaling that to 2175 should be ~154 lbs/hr.
So, if we assume that BSFC is ~.5
Then:
125.7 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2011 HP @ 1450 psi
154 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2464 HP @ 2175 psi
So, if that is the case, then I would agree with you that injector swaps are probably not necessary, but I'd like to see if you can comment on that.
So, if we assume that BSFC is ~.5
Then:
125.7 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2011 HP @ 1450 psi
154 lbs/hr / .5 lbs/hr per hp of fuel * 8 cylinders = 2464 HP @ 2175 psi
So, if that is the case, then I would agree with you that injector swaps are probably not necessary, but I'd like to see if you can comment on that.
Originally Posted by Bigg_Gunz
So here is a small story ...another engineer while at the superbowl had his car stolen. And an aerospace engineer by chance was leaving the parking area and gave him a ride to a rental car company.
On the way there a conversation took place. The Aerospace engineer was driving a car with a rotary engine. Which sparked the idea in our engineer head the two talked. Needless to say... if you look at the back of the cam on the 2014 LT1 its a tri-lobe extremely similar to the rotary engine. Rotary engines love to rev and they are stable in rotation. We chopped off the acute angle edges on our tri-lobe as you can tell. The pump has a roller lifter. And presto! It works so well there are no measureable forces, It's like it not even there. Now thats engineering!
On the way there a conversation took place. The Aerospace engineer was driving a car with a rotary engine. Which sparked the idea in our engineer head the two talked. Needless to say... if you look at the back of the cam on the 2014 LT1 its a tri-lobe extremely similar to the rotary engine. Rotary engines love to rev and they are stable in rotation. We chopped off the acute angle edges on our tri-lobe as you can tell. The pump has a roller lifter. And presto! It works so well there are no measureable forces, It's like it not even there. Now thats engineering!
#349
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VVT is not going away the aftermarket has to come forward with the technology, people, and tools sooner rather than later
Is that true for all future GM V8 engines including the upcoming LT4 and Big Brother? I have to believe VVT is less intrusive in performance applications and less so for the big hp motors.
#350
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Ok Mr. BG...I stayed up late after watching for news updates all day long per your heads up last week concerning more revelation on the new beast today, and...nada.
I was sure there was going to be something about me receiving a gift of an LT1 with a nice new shiny C7 wrapped around it. What happened?
I was sure there was going to be something about me receiving a gift of an LT1 with a nice new shiny C7 wrapped around it. What happened?
#351
Unfortunately, there is one thing you are missing. On a DI engine, the injector cannot fire for 720deg of crank rotation like a PI engine. The fuel cannot be injected for a large majority of the exhaust stroke and during the power stroke. This means that at best, you could have half your calculated power. Still alot!
I appreciate your information in this thread, but this is a stretch. Direct injection engines have beein using tri-lobed cam drives for almost a decade. My 2007 car (Mazda) has a high-pressure fuel pump driven by a tri-lobe on the end of the intake cam. Also, the LNF (2.0 Turbo Ecotec) has used it for many years too....
I appreciate your information in this thread, but this is a stretch. Direct injection engines have beein using tri-lobed cam drives for almost a decade. My 2007 car (Mazda) has a high-pressure fuel pump driven by a tri-lobe on the end of the intake cam. Also, the LNF (2.0 Turbo Ecotec) has used it for many years too....
Good morning to you sir
Bigg Gunz
Last edited by Bigg_Gunz; 12-04-2012 at 09:45 AM.
#352
Ok Mr. BG...I stayed up late after watching for news updates all day long per your heads up last week concerning more revelation on the new beast today, and...nada.
I was sure there was going to be something about me receiving a gift of an LT1 with a nice new shiny C7 wrapped around it. What happened?
I was sure there was going to be something about me receiving a gift of an LT1 with a nice new shiny C7 wrapped around it. What happened?
Hang tight, I am sure more information is going to be release soon. I'm NOT sure what happen with Monday release, or why the change for it. It is coming I can assure you of that so hang in there.
Bigg Gunz
#353
VVT is here to stay I am concrete with that statement. As we are still in testing with big brother I am not allow to elaborate additionally on that.
Bigg Gunz
#354
Thank you for addressing my questions BG. While not completely thrilled with all the news you have brought us, I am grateful for you taking the time.
I thought of one more for you. What about correcting the speedo for gear swaps, will that be possible with these new E92 equipped cars?
I thought of one more for you. What about correcting the speedo for gear swaps, will that be possible with these new E92 equipped cars?
Yes you can make those needed adjustments, The only thing that is off limits in the E92 ECM is Fuel tables and High Pressure Solenoid Fuel tables. There isn't really any bad news given, this is going to be a fun engine for the aftermarket and regular consumer. Everyone will win in the end.
Bigg Gunz
#355
The LS2 manifold has more volume/space than a regular LS6 manifold. This is due to the larger displacement of the 6.0 engine vs 5.7.
So taking a LS2 manifold and putting on a 5.7 you will lose some power and some torque. Due mainly to the velocity drop and pressure waves produced. The port shape is slight different as well this will also rob some power.
My question is what do you have the LS2 intake manifold installed on? As I can give you a exact accurate reason.
Bigg Gunz
#356
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The LS2 manifold has more volume/space than a regular LS6 manifold. This is due to the larger displacement of the 6.0 engine vs 5.7.
So taking a LS2 manifold and putting on a 5.7 you will lose some power and some torque. Due mainly to the velocity drop and pressure waves produced. The port shape is slight different as well this will also rob some power.
My question is what do you have the LS2 intake manifold installed on? As I can give you a exact accurate reason.
Bigg Gunz
So taking a LS2 manifold and putting on a 5.7 you will lose some power and some torque. Due mainly to the velocity drop and pressure waves produced. The port shape is slight different as well this will also rob some power.
My question is what do you have the LS2 intake manifold installed on? As I can give you a exact accurate reason.
Bigg Gunz
I believe it is common knowledge at this point the LS2 intake is a big hinderance on that motor. a swap to a FAST does more for an LS2 then any other LS varient.
Last edited by disc0monkey; 12-04-2012 at 08:51 AM.
#357
I think you covered it with the LS2 making less power on the LS1/6. IIRC some have even gone far enough to report the LS6 making more(minute) or same horsepower on the LS2.
I believe it is common knowledge at this point the LS2 intake is a big hinderance on that motor. a swap to a FAST does more for an LS2 then any other LS varient.
I believe it is common knowledge at this point the LS2 intake is a big hinderance on that motor. a swap to a FAST does more for an LS2 then any other LS varient.
Bigg Gunz
#359
TECH Fanatic
Yes you can make those needed adjustments, The only thing that is off limits in the E92 ECM is Fuel tables and High Pressure Solenoid Fuel tables. There isn't really any bad news given, this is going to be a fun engine for the aftermarket and regular consumer. Everyone will win in the end.
Bigg Gunz
Bigg Gunz
You are also suggesting that fueling is locked. So for an NA app vs an FI app the fueling will not be optimised for both. This is a fail then. And people will still want to mess with fueling, perhaps by running a programable MAF etc.
The only way it would work properly if the ECU has a feedback loop and perhaps even wideband closed loop.
But if previous models are anything to go by OEM fueling is not optimal LBT. Nor is timing set at MBT across the load range.
So at best it will be a kludge and at worst pointless IMO.
But happy to be proven wrong. I guess we will see when the first cars hit the dyno.
As long as we can mess with the airflow tables or sensors we will have fueling control