New LT1 for 2014 6.2l alum block
12-27-2012, 12:22 PM
#721
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So, are you hinting that the new LT1 will be flex fuel? Also, did I catch a hint of an EGT sensor there? Also, you may have missed it, but NOx control is the answer!! 
12-27-2012, 01:48 PM
#722
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my question is, will there be a version of the LT1 head to retrofit onto the Gen3/4 engines (6.0 and higher)? i THINK the high pressure pump could be run from the old cam sensor location on the back on the gen 3 blocks but the real issue is getting the heads to fit.
12-27-2012, 08:00 PM
#723
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You mention running .013 - .015 on the top? That's .0036 per inch of piston... your pistons are "3.70 size assuming it is still stock bore..... That is extremely tight for 2618 alloy...
Can you get away with .0036 per inch of piston? Yes... However, now your piston to wall clearance has no room for machine error...... this Engine is going have to be spot on to prevent the piston rocking at BDC because of the taper and causing the top ring to bind or flutter or bounce. And when the piston makes it back to TDC for the dynamic pressure ...it is going to pressurize the space between the top and 2nd and causing the top ring to bounce, flutter, wobble...bind up and pull the ring landing off.
Or you're going run into issues with burning oil, flakes in the oil....under load and heat. Don't forget the piston rings need to expand and they will expand under load and heat.
With that tight of gap they are going to butt ends and keep butting until the piston takes out itself and or lift the piston landing to expose your 2nd ring to combustion.
I urge you to reconsider running that tight of a clearance.
Reply back advise if you are consider running less 700HP or running 700HP more.... when dealing with V6 engines 700HP is vertex of what to gap rings. So that I can recommend more appropriate tolerance on ring gaps.
Bigg Gunz
Can you get away with .0036 per inch of piston? Yes... However, now your piston to wall clearance has no room for machine error...... this Engine is going have to be spot on to prevent the piston rocking at BDC because of the taper and causing the top ring to bind or flutter or bounce. And when the piston makes it back to TDC for the dynamic pressure ...it is going to pressurize the space between the top and 2nd and causing the top ring to bounce, flutter, wobble...bind up and pull the ring landing off.
Or you're going run into issues with burning oil, flakes in the oil....under load and heat. Don't forget the piston rings need to expand and they will expand under load and heat.
With that tight of gap they are going to butt ends and keep butting until the piston takes out itself and or lift the piston landing to expose your 2nd ring to combustion.
I urge you to reconsider running that tight of a clearance.
Reply back advise if you are consider running less 700HP or running 700HP more.... when dealing with V6 engines 700HP is vertex of what to gap rings. So that I can recommend more appropriate tolerance on ring gaps.
Bigg Gunz
We are targeting 550-600 rwhp. I have a 3 bar map setup to install and we plan on taking the boost into the high teens.
Of course there is water/meth injection.
The piston to cylinder clearance is at .004" currently, and if it matters I am running an adjustable vaccum pump setup.
Currently the heads and intake will remain stock, but finances aren't a problem if that needs to change.
Thanks for taking time to offer some advice!
On a side note, tuning the direct injection is very intersting in comparison to your normal e38 setup. I did some baseline tuning on the car in stock form to get my feet wet. It seems direct injection likes a little leaner mixture. I did find that there are some tip in torque tables that cannot be skewed because it will go into reduced engine power. I will have to spend more time with that once its up and going.
I assume the direct injectors on this engine have plenty of output for our goal, and the intank pump will be replaced with a zl1 pump.
thanks,
Ryan
12-28-2012, 08:09 AM
#724
Ryan, If you're running a vacuum pump setup, wouldn't you be able to run the rings in a little looser configuration? Read a cool thing on vacuum pump systems and their gains on Enginelabs. A guy tested that on his turbo 3800 on the dyno with just a shop vac hooked up to his pcv system and pulled in an extra 15 or so hp.
It's a cool read: LINK
It's a cool read: LINK
12-28-2012, 01:05 PM
#725
BG - Welcome back from the holiday.
I had a thought/question along the lines of one of your earlier posts over the break:
Has GM thought of or has GM entertained the idea of further developing some of this engine's aspects in an open source fashion with closer collaboration between the aftermarket and engineering?
Without aftermarket providers or GM exposing all of their proprietary information, maybe there is a way where the two entities could share data in common ground areas of the architecture? If the aftermarket starts hitting the edges/limits of the ECM programming, GM could take a look at changes on their side and as the aftermarket goes in directions that will overstress parts of the engine, GM might steer their processes with hints/tweaks.
I had a thought/question along the lines of one of your earlier posts over the break:
... So that company/business/brand becomes out of touch with the customers and starts producing things they don't need or want... Any of you reading this now can name at least 10 businesses that are out of touch. (PLEASE DO NOT NAME THEM).
But by the time the message reaches us engineers/innovators, its been polished so much that usually it doesn't warrant a additional review. We cannot do anything or react, if the message we receive has no critical information.
No one likes to carry bad news this is why they polish the message in the corporate world.
So teams are formed and sent to sniff out the real missing data. On here we found a very LARGE missing piece of the puzzle we found the squeaking wheel of performance. Your concerns are noted and then reports are formed by engineers for presentations. Legit concerns, updates, problems, and your suggestion are taken very seriously around the round table.
Just because other engineers and teams doesn't respond or reply back or login, they read you loud and clear. All BIG 3 are here I can 100% assure they are if you make enough noise in the proper fashion. You can control the direction of performance and power train.
Chassis Design, Interior etc are carried out by other divisions so don't waste your time on that
But Performance and Power train you can control.....
I respect each and every one of you, you guys are invaluable keep us on our toes and doing our best. We root for the little guys...they guys that have small budgets or no budgets. Anyone with a bottomless bank account can make + 2000HP. The playing field for the little guy isn't even...Engineers are ALWAYS for the little guys.
The way you guys take these OEM parts modify them in ways never thought and make tremendous power output, or the way you guys rewire/reverse engineer systems and make them play nicely together. Is amazing... a lot of you up & coming guys would make great engineers. You are naturally curious and ask all the right questions.
On slow days we sit and smile at what you guys are able to pull off in 600.00 or less, or they way you take common hand tools and build great motors. You GUYS ROCK!! I mean that we can't give you money or secrets, but us engineers can be sneaky & leave high amounts of power on the table for you to harvest and so far you guys are finding your gifts from us.
The 2014 LT1 will be NO different, you Hot Rodders are going to adore this thing we created. We left some dinner on the table.
Bigg Gunz
But by the time the message reaches us engineers/innovators, its been polished so much that usually it doesn't warrant a additional review. We cannot do anything or react, if the message we receive has no critical information.
No one likes to carry bad news this is why they polish the message in the corporate world.
So teams are formed and sent to sniff out the real missing data. On here we found a very LARGE missing piece of the puzzle we found the squeaking wheel of performance. Your concerns are noted and then reports are formed by engineers for presentations. Legit concerns, updates, problems, and your suggestion are taken very seriously around the round table.
Just because other engineers and teams doesn't respond or reply back or login, they read you loud and clear. All BIG 3 are here I can 100% assure they are if you make enough noise in the proper fashion. You can control the direction of performance and power train.
Chassis Design, Interior etc are carried out by other divisions so don't waste your time on that
But Performance and Power train you can control..... I respect each and every one of you, you guys are invaluable keep us on our toes and doing our best. We root for the little guys...they guys that have small budgets or no budgets. Anyone with a bottomless bank account can make + 2000HP. The playing field for the little guy isn't even...Engineers are ALWAYS for the little guys.
The way you guys take these OEM parts modify them in ways never thought and make tremendous power output, or the way you guys rewire/reverse engineer systems and make them play nicely together. Is amazing... a lot of you up & coming guys would make great engineers. You are naturally curious and ask all the right questions.
On slow days we sit and smile at what you guys are able to pull off in 600.00 or less, or they way you take common hand tools and build great motors. You GUYS ROCK!! I mean that we can't give you money or secrets, but us engineers can be sneaky & leave high amounts of power on the table for you to harvest and so far you guys are finding your gifts from us.
The 2014 LT1 will be NO different, you Hot Rodders are going to adore this thing we created. We left some dinner on the table.
Bigg Gunz
Has GM thought of or has GM entertained the idea of further developing some of this engine's aspects in an open source fashion with closer collaboration between the aftermarket and engineering?
Without aftermarket providers or GM exposing all of their proprietary information, maybe there is a way where the two entities could share data in common ground areas of the architecture? If the aftermarket starts hitting the edges/limits of the ECM programming, GM could take a look at changes on their side and as the aftermarket goes in directions that will overstress parts of the engine, GM might steer their processes with hints/tweaks.
12-28-2012, 06:39 PM
#726
Originally Posted by Suaveat69
Gunz,
Can you elaborate on GM electric varialbe ratio rocker arms? (like the Hot-Rockers except electric)Yes, I can what questions do you have pertaining to the rockers?
CAn you say how many models the C7 will sport (base, GS,Z06,ZR1 ect.) and what will ultimately be top dog. I cannot reveal that particular information but what I can say is the TOP Corvette is going after HYPER CARS and NOT SUPERCARS.
Can you comfirm or denie that ther will bigger displacement than 376 CI? No comment
Why does GM continue to use "liters" instead of CI in their designations for V8's? Marketing continues to use both depending on the vehicle being pitched. 4, 6, 8 can be spin for personal interest. Liters in small displacement over shadows the factor of cu in. Larger displacement engines sound tougher when stating how many cu in is stuffed in the block. Just like saying 8.2 liters... see it sounds lazy and large...however saying 502 cu in sounds tougher and more extreme. And at the end of the day its the same. Just a title. And all these engines are designed in metric as the calculations are simplified, that's just engineering in general. Thanks
Bigg Gunz 1. Rockers-What are the ratios ranges of the RA? Can you say why they are not available currently or when they might be available or if they will be on the LT1? Will they ever be released as just a OTC part if not used in production?
2. I assume from your post that there will be lager than 37 6C.I. You said HOLS7--is this 5th Gen or just a 4th Gen?
3. What was the reason to keep the BS @ 4.4 instead of move it to 4.5 like the RO7?
4. Regarding the 4.3-Any reason why it is not 4.00 bore? Why was there not a LSX version of the 4.3 released all these years?
5. Has GM done any testing regarding a 16 volt system (ignition esp) regarding reduced emissions and increased MPG?
6. Have YOU done any testing on higher HP engines regarding Twin TB's or even ITB's in factory form? If so has this testing revealed any relevant info.
Thanks
Gunz,
Can you elaborate on GM electric varialbe ratio rocker arms? (like the Hot-Rockers except electric)Yes, I can what questions do you have pertaining to the rockers?
CAn you say how many models the C7 will sport (base, GS,Z06,ZR1 ect.) and what will ultimately be top dog. I cannot reveal that particular information but what I can say is the TOP Corvette is going after HYPER CARS and NOT SUPERCARS.
Can you comfirm or denie that ther will bigger displacement than 376 CI? No comment
Why does GM continue to use "liters" instead of CI in their designations for V8's? Marketing continues to use both depending on the vehicle being pitched. 4, 6, 8 can be spin for personal interest. Liters in small displacement over shadows the factor of cu in. Larger displacement engines sound tougher when stating how many cu in is stuffed in the block. Just like saying 8.2 liters... see it sounds lazy and large...however saying 502 cu in sounds tougher and more extreme. And at the end of the day its the same. Just a title. And all these engines are designed in metric as the calculations are simplified, that's just engineering in general. Thanks
Bigg Gunz
2. I assume from your post that there will be lager than 37 6C.I. You said HOLS7--is this 5th Gen or just a 4th Gen?
3. What was the reason to keep the BS @ 4.4 instead of move it to 4.5 like the RO7?
4. Regarding the 4.3-Any reason why it is not 4.00 bore? Why was there not a LSX version of the 4.3 released all these years?
5. Has GM done any testing regarding a 16 volt system (ignition esp) regarding reduced emissions and increased MPG?
6. Have YOU done any testing on higher HP engines regarding Twin TB's or even ITB's in factory form? If so has this testing revealed any relevant info.
Thanks
12-28-2012, 08:41 PM
#729
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where theres a will theres a way, etc.. if the bolt holes are even close it can be modified. or a "LT/LSX" head could be made. exhaust valve layout isnt an issue at all. change the flange on whatever headers.
12-28-2012, 09:01 PM
#730
I'm certain the two heads are vastly different. Because of the port swap, head bolts will be in different places. And, it won't be a swap heads/intake/exhaust affair. You'll need to yank the block to change pistons.
It'd be substantially easier to get a GenV engine into a car vs. modding everything to put the heads on a gen III or IV block.
It'd be substantially easier to get a GenV engine into a car vs. modding everything to put the heads on a gen III or IV block.
12-28-2012, 09:12 PM
#731
TECH Resident
As I've stated... The ECM and please refer to these as the ECM's is Now a virtual client. The ECM has a microprocessor that is now virtualize. Unlike before.. What that means is means is the ENGINE MANAGEMENT DEVELOPERS put more than one operating system on this single processor. The hypervisor separates between each OS. The OS modeling through a new authoring feature and IP specification import function. Through TLS and TLM as well as can be used in a wide variety of applications including systems such as engine and transmission control, braking systems, power steering systems, chassis domain control, airbags, advanced driver assistance systems, and infotainment systems.
The virtualization easily allows the system to overwrite any changes or deny unauthorized access. This ECM contains software tools enabling greater visibility and controllability into the system software execution.
Bigg Gunz
12-28-2012, 09:55 PM
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I'm certain the two heads are vastly different. Because of the port swap, head bolts will be in different places. And, it won't be a swap heads/intake/exhaust affair. You'll need to yank the block to change pistons.
It'd be substantially easier to get a GenV engine into a car vs. modding everything to put the heads on a gen III or IV block.
It'd be substantially easier to get a GenV engine into a car vs. modding everything to put the heads on a gen III or IV block.
12-28-2012, 11:31 PM
#734
I think people are thinking/wishing they could do a head, intake & injection system swap onto their existing engines in their cars without pulling the block.
The GenV LT1 heads are a pretty radical departure from what the GenIII/IV heads.
The GenV LT1 heads are a pretty radical departure from what the GenIII/IV heads.
12-28-2012, 11:41 PM
#735
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Awesome info BG, much thanks. I have some questions though.
1) Why did GM decide to not make a 3.6TT optional for this truck. I know one is in the cards for the CTS, but after the success Ford has had with Ecoboost, I feel that GM has been caught flat footed. Are you guys worried about the Al-bodied F-150?
2) Why did the LTG turn out to be such a dog in relation to the N20? What does BMW know about powertrain that GM doesn't, and what advantages do they have that led to the LTG getting shaded so badly?
Thanks, it's has been a dream of mine to actually talk to a GM engineer for a long time.
1) Why did GM decide to not make a 3.6TT optional for this truck. I know one is in the cards for the CTS, but after the success Ford has had with Ecoboost, I feel that GM has been caught flat footed. Are you guys worried about the Al-bodied F-150?
2) Why did the LTG turn out to be such a dog in relation to the N20? What does BMW know about powertrain that GM doesn't, and what advantages do they have that led to the LTG getting shaded so badly?
Thanks, it's has been a dream of mine to actually talk to a GM engineer for a long time.
12-29-2012, 01:58 AM
#736
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1) it looks like teh water jackets would work together
2) it looks like the bolts arent too far off. the issue would be the dowels per BG
2A) the smaller bolts are mostly eliminated, however, 2 are still used on either head.
the canted valves and shallower angle mean one wouldnt really need new slugs. you wont get the same exact power and efficiency as the LT1 but i would bet you could still get a hell of a bump in both.
while the LT1 is a 'radically new' engine. it is not the same change as the gen 1 to gen 3. the gen 1 and 3 engines have nothing in common but the bore spacing. the gen 3/4 and 5 share deep skirt mains, the oiling system, similar water jackets, front cover, front cam sensor, etc. while all these parts have evolved... they are not the leap the sbc to ls1 was. the ls1 was a mammal to the sbc dinosaur. the LT1 is the flying bird to the LS1's feathery raptor.
with that in mind... BG: would it be ok to tell us the head bolt to head bolt measurement/placement on the heads?
12-29-2012, 07:53 AM
#737
I think one (of the many) tricks of this engine is the piston. It helps swirl the intake and fuel charge while guiding it towards the exhaust valve. The pistons are part of the combustion chamber in this engine much more than any other engine. Without the pistons, these heads won't work.
As I recall, GevIII and GenIV heads are interchangeable-after considering bore size for the larger valved heads.
Even if you do manage to get a GenV head on a GenIII or IV block, without the head specific pistons, you'll lose power. There are a slew of great heads available for the GenII/IV engines.
SO: To get these heads on an earlier engine:
-Pull the engine and get custom pistons designed and made;
-Modify the block by welding up the original bolt holes;
-Modify the block with new bolt bosses;
-Modify the block with re-located dowels;
-Modify the block by welding up coolant holes that may not be where they belong;
I'm certain this just scratches the surface-how are you gonna work that cam and mechanical pump into the block?
Reminder: The head bolts go down into castings towards the bottom of the block. It's not like you can drill & tap the deck.
As I recall, GevIII and GenIV heads are interchangeable-after considering bore size for the larger valved heads.
Even if you do manage to get a GenV head on a GenIII or IV block, without the head specific pistons, you'll lose power. There are a slew of great heads available for the GenII/IV engines.
SO: To get these heads on an earlier engine:
-Pull the engine and get custom pistons designed and made;
-Modify the block by welding up the original bolt holes;
-Modify the block with new bolt bosses;
-Modify the block with re-located dowels;
-Modify the block by welding up coolant holes that may not be where they belong;
I'm certain this just scratches the surface-how are you gonna work that cam and mechanical pump into the block?
Reminder: The head bolts go down into castings towards the bottom of the block. It's not like you can drill & tap the deck.
Last edited by Paul Bell; 12-29-2012 at 09:34 AM.
12-29-2012, 09:10 AM
#738
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Seems like a lot of work for nothing, probably wont work anyways. Id rather transplant an LT1 in its original glory and how it was designed to work into my ls car than a ls/lt1 hybrid thats not designed to work as a hybrid. Im sure it will be easy enough to swap a whole lt1 into an lsx car with gm already planning crate engines.
12-29-2012, 10:29 AM
#740
