New LT1 for 2014 6.2l alum block
12-29-2012, 11:02 AM
#742
Nice info about the Camaro LS7.
Lots of conjecture at other forums.
As Chevrolet always puts their newest innovations in the Corvette a year before the other car lines, the Camaro will keep the LS3 at least through the 2014 model year. Seems like a nice place to stick the LS7 before the 2015 Camaro gets the GenV engines.
Lots of conjecture at other forums.
As Chevrolet always puts their newest innovations in the Corvette a year before the other car lines, the Camaro will keep the LS3 at least through the 2014 model year. Seems like a nice place to stick the LS7 before the 2015 Camaro gets the GenV engines.
12-29-2012, 12:37 PM
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Thanks for your response. True I was comparing specs based off of stock alloys pistons, not the 2618's.
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. In the future do your best to break the habit of build engines for RWHP...there is too many variables...like drive line frictional losses, dynos read outs improper on adjustments and setups, environment temps etc for RWHP to ever be accurate enough to be useful to yourself or the client.
Of course there is water/meth injection. Provides additional oxygen and takes heat out of the combustion process through evaporation. Which is great I think....if needed
The piston to cylinder clearance is at .004" currently, and if it matters I am running an adjustable vaccum pump setup. In you're application this is great but slightly overkill for the power level.
Currently the heads and intake will remain stock, but finances aren't a problem if that needs to change. Deburring them of sharp edges is fine other than that you're fine. Pressurization will overcome other variables.
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. Feeding Direct Injection too much fuel is always going to hurt it... Direct Injection is an efficiency process... only slight amounts of fuel are needed for HP gains......Needless to say why the 2014 LT1 is locked down.
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.I concur...
thanks,
Ryan
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. In the future do your best to break the habit of build engines for RWHP...there is too many variables...like drive line frictional losses, dynos read outs improper on adjustments and setups, environment temps etc for RWHP to ever be accurate enough to be useful to yourself or the client.
Of course there is water/meth injection. Provides additional oxygen and takes heat out of the combustion process through evaporation. Which is great I think....if needed
The piston to cylinder clearance is at .004" currently, and if it matters I am running an adjustable vaccum pump setup. In you're application this is great but slightly overkill for the power level.
Currently the heads and intake will remain stock, but finances aren't a problem if that needs to change. Deburring them of sharp edges is fine other than that you're fine. Pressurization will overcome other variables.
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. Feeding Direct Injection too much fuel is always going to hurt it... Direct Injection is an efficiency process... only slight amounts of fuel are needed for HP gains......Needless to say why the 2014 LT1 is locked down.
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.I concur...
thanks,
Ryan
Gap the 1st ring .0048 per inch so if you're bores are stock size.. .0048 x 3.70 = .017 <--- after break in this will change to .01796
Gap the 2nd ring .0053 per inch so if your bores are stock size .... .0053 x 3.70 =.01961 <---after break in this will change to .01995 which is fine.
At 205'f coolant temperature...your piston surface temperature is 482'f @ 3mm dept.... under extreme rpm and force induction your piston surface temperature is going to rise 571'f @ 2mm dept. Under optimal AFR's... go to rich or too lean...and the piston crown and rings are going to expand beyond...0008 - .001 maybe even more... Going to about 571'f piston surface temp and 2618 pistons are weaker than stock pistons because of there terrible ability to transfer heat into the cylinder walls the run away annealing process is now happening to the piston and over time this is why scuffing, scratches and micro weld and pitting occurs to 2618 pistons...and @ +571'f the gasoline enter the chamber is frying and baking onto the piston surface and compounding the issue...this is known as "CARBON" build up....this is from also poor atomization of the fuel, poor flame travel do to the piston contours on the surface... And the hotter the piston gets from the compounding process... detonation,knock, and pre-ignition takes...over...carbon absorbs radiant heat...and this point...on the heads the combustion chamber is cooking and heating up... a crack between the intake and exhaust valve will occur..drop a valve or even a valve seat from this extreme heat....in a real bad situation...you're going to crack the cylinder wall or cylinder sleeve... Now You're in a better position because those oil squirters is going to keep this process from happening to your pistons they going to cool the bottom of the pistons and take heat out the piston stop the run away annealing process over the engine life span... Now...... back on the subject.....
Every bore is different..... the bore diameter has to be spot on, for every piston or you'll be upset later. Your Piston to wall clearance depends on this....after you get the clearance right. Assuming your machinist has finished the bores properly and kept bore distortion to a minimum. 56-59 degree cross hatch hone finishes...this is optimal to trap oil in the cylinder walls since you are running a tight upper ring gap and synthetic oil after break in. Stay within this RANGE okay? You don't want the oil film to be too thin, causing ring and cylinder scuffing! And if you go to flat on the cross hatch the piston will hydro plane in the bore and cause excessive oil consumption!
Now once again..... if you're going to stay below 700HP.... Can run these tighter ring gaps.. above if you're going above 700HP+ then your going to have to open it up or face major problems. Down the road......and the above figures are useless......
If you're a 100% sure you are NOT going to take this engine above +700HP..... Then the piston to wall clearance needs to be .004 alright? Now if your going above 700HP+ your piston to wall clearance needs to be .0041 because your piston will slightly expand another .00075+ to bring you back to the perfect piston to wall clearance of .00392 alright? Your piston will NOT "SLAP" until .00475 clearance is seen. You have a narrow rang to play with.... Hold these tolerances and your engine should life 73,000 miles give or take 5,000 miles... which is as gone as it gets with 2618's alloys...This is working with 2618 ALLOY ONLY and only for "3.70 bores. DO NOT ATTEMPT THESE CLEARANCES on any other engine!!
Reply back with your current measurements on cylinder bores, piston crown, and piston middle section...
Bigg Gunz
12-29-2012, 12:58 PM
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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?In some aspect yes, however the aftermarket usually improves upon OEM development and products to save millions in capital on innovative design,research and development from a blank sheet of paper stand point. So basically they assume very little risk because of the product/service is around existing. Think of S3 verses Iphone 5.... from that visual you can see the point I am making.
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 don't know if you know this or not...But some of these aftermarket tuning company's are in BED with Big 3 OEM engine management engineers.... I'm always brutally honest with the truth... A lot of these companies get contracts/licenses from BIG 3 on access to these new ECM's. Whether it's "CAN TUNES OR FULL TUNING ABILITY... Theses New ECM's making it to market are so encrypted with rolling keys. It would be the year 2030 or more before a BRUTE FORCE PROGRAM running 24HRS A day... could get pass the first fail safe.
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?In some aspect yes, however the aftermarket usually improves upon OEM development and products to save millions in capital on innovative design,research and development from a blank sheet of paper stand point. So basically they assume very little risk because of the product/service is around existing. Think of S3 verses Iphone 5.... from that visual you can see the point I am making.
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 don't know if you know this or not...But some of these aftermarket tuning company's are in BED with Big 3 OEM engine management engineers.... I'm always brutally honest with the truth... A lot of these companies get contracts/licenses from BIG 3 on access to these new ECM's. Whether it's "CAN TUNES OR FULL TUNING ABILITY... Theses New ECM's making it to market are so encrypted with rolling keys. It would be the year 2030 or more before a BRUTE FORCE PROGRAM running 24HRS A day... could get pass the first fail safe.
Completely off the subject...but I have a question... Why does tuning cost so much in the aftermarket anyway?
Bigg Gunz
12-29-2012, 01:13 PM
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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? no comment Can you say why they are not available currently or when they might be available or if they will be on the LT1?They will NOT appear on the GEN V/ 2014 LT1, However they will make it into production on the impala and 3 other vehicles Will they ever be released as just a OTC part if not used in production?Eventually yes, after being release they will make it into the world of the aftermarkets.
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?GEN 4, if it NOT broke don't fix it
3. What was the reason to keep the BS @ 4.4 instead of move it to 4.5 like the RO7?proven structural strength, and heritage.
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?the 4.3 engine is 4.00in. bore And the engine was being redeveloped and tested is why there was not a 4.3 over the years.
5. Has GM done any testing regarding a 16 volt system (ignition esp) regarding reduced emissions and increased MPG? no comment
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.
Have I personally tested an engine with dual throttle bodies no... Have I worked with engineers on designing systems for dual throttle bodies? Yes..
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
1. Rockers-What are the ratios ranges of the RA? no comment Can you say why they are not available currently or when they might be available or if they will be on the LT1?They will NOT appear on the GEN V/ 2014 LT1, However they will make it into production on the impala and 3 other vehicles Will they ever be released as just a OTC part if not used in production?Eventually yes, after being release they will make it into the world of the aftermarkets.
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?GEN 4, if it NOT broke don't fix it
3. What was the reason to keep the BS @ 4.4 instead of move it to 4.5 like the RO7?proven structural strength, and heritage.
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?the 4.3 engine is 4.00in. bore And the engine was being redeveloped and tested is why there was not a 4.3 over the years.
5. Has GM done any testing regarding a 16 volt system (ignition esp) regarding reduced emissions and increased MPG? no comment
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.
Have I personally tested an engine with dual throttle bodies no... Have I worked with engineers on designing systems for dual throttle bodies? Yes..
Thanks
12-29-2012, 01:15 PM
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I got lucky!! I set the top gaps to about .018 and the 2nd rings at .020" got the shortblock together yesterday. I dont have all the piston specs here with me, but I think they are back at the shop.
Here are some photos of the new pistons, I had diamond build them for 10:1 compression based on stock gasket and chamber volume.
Here are some photos of the new pistons, I had diamond build them for 10:1 compression based on stock gasket and chamber volume.
12-29-2012, 01:16 PM
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Bigg Gunz
12-29-2012, 01:21 PM
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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?Supplier issues with water cooled turbos was the root cause of the delay. No sir...we aren't worried not 1% about the competitors. You'll see why shortly.
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? Could you be clearer? I'm not sure if I'm understanding the question your asking.
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?Supplier issues with water cooled turbos was the root cause of the delay. No sir...we aren't worried not 1% about the competitors. You'll see why shortly.
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? Could you be clearer? I'm not sure if I'm understanding the question your asking.
Thanks, it's has been a dream of mine to actually talk to a GM engineer for a long time.
Bigg Gunz
12-29-2012, 01:24 PM
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You're on the money with calucations!!!
Bigg Gunz
Last edited by Bigg_Gunz; 12-29-2012 at 01:36 PM.
12-29-2012, 01:35 PM
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12-29-2012, 02:08 PM
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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.
the hp pump would need a custom cam of sorts with a tri lobe in the position the reluctor wheel on the gen 3 cams was in. it would use the now unused
cam sensor hole. the one issue there would be oiling.
the DI itself will provide gains in a lot of places as would the heads. it is optimized with the pistons used BUT i would bet you would still see gains over the standard gen3/4 head and port efi. nice gains at that.
12-29-2012, 02:09 PM
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I'm pretty sure everyone knows by now what to expect with the new GEN 5 V8's.
The 4.3 VVT V6 and its output, is going to catch everyone off guard. Especially in these newer lighter vehicles. The 4.3 VVT V6 is in a position to really upset more than a few V8 owners.
Bigg Gunz
The 4.3 VVT V6 and its output, is going to catch everyone off guard. Especially in these newer lighter vehicles. The 4.3 VVT V6 is in a position to really upset more than a few V8 owners.
Bigg Gunz
12-29-2012, 02:58 PM
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I'm pretty sure everyone knows by now what to expect with the new GEN 5 V8's.
The 4.3 VVT V6 and its output, is going to catch everyone off guard. Especially in these newer lighter vehicles. The 4.3 VVT V6 is in a position to really upset more than a few V8 owners.
Bigg Gunz
The 4.3 VVT V6 and its output, is going to catch everyone off guard. Especially in these newer lighter vehicles. The 4.3 VVT V6 is in a position to really upset more than a few V8 owners.
Bigg Gunz
12-29-2012, 03:23 PM
#756
Going back to your question I would expect some of these aftermarket tuning abilities to have licensed help from that OEM company. And I would expect that cost of that license to be significant for you the customer after the severe mark up that happens in the USA today.
I expect that there would be resistance from the aftermarket companies that enjoy the inside access today, but (as you point out) the core hardware of the engine will remain unchanged. The development of engines is following a process that seems to me to be converging with that of software/technology products. Those industries have seen a lot of innovation arise from open source development and I'd expect that OEM's would see some unexpected developments by doing the same.
12-29-2012, 04:00 PM
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12-29-2012, 04:42 PM
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Yes, no question has DOWN GERMANY dominates all countries on this rock called EARTH in terms of engineering.
For instance... you're question is about engines GM vs BMW. Germany has a niche for math and science is why they dominate with an iron fist.
The people who gave American its pride were German... "werner von braun" & "Albert Einstein" and countless others from abroad...its sad but true...
The GERMANS are some of the hardest working people you'll ever want to see. Give credit where it due. I'm 100% American born in Lincoln Nebraska raised here in the USA.
The sad fact...is in order to obtain the highest level of skill and education I had to go abroad internationally. Being smart in America isn't cool....now a days if your educated you're weird. The cuts to education has people believing ridiculous things by the gov and hollywood actors.
Look at America today... most of the public doesn't know that the biggest leading corporations & colleges in this country go abroad for the best talent....
Have you ever heard of a "H-1B VISA"? Kids with abnormal high math an science scores get the full ride on this visa and even get paid to come here.
And MIT,CIT, and all these major universities uses this as a tool to obtain the best... The talent today isn't being American MADE it's being imported just like everything else.
I make over well over 550K a year and I can tell you about a kid that was just recruited from shanghai and another from Frankfurt that are going to make 6 figures as a sign on bonus... and they are 23 and 26 years old...
Yes these people are better engineers....until we raise the bar on science and math we will continue to adopt foreign talent nationalize them call them AMERICAN.
The Germans was responsible for us getting to the moon that was over 40 years ago...so what does that tell you about today and their ability with engines?
WAKE UP AMERICA!
Bigg Gunz
12-29-2012, 06:16 PM
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Thanks Bigg Gunz,
Can you enlighten as to why you guys (GM powertrain engineers) decided to make the ATS-V with a TTV6 instead of this new LT1? I think many enthusiast subjectively prefer a small block even if it's objectively inferior to a turbo six.
PS: I was born in Lincoln too. GBR.
Can you enlighten as to why you guys (GM powertrain engineers) decided to make the ATS-V with a TTV6 instead of this new LT1? I think many enthusiast subjectively prefer a small block even if it's objectively inferior to a turbo six.
PS: I was born in Lincoln too. GBR.
12-29-2012, 09:50 PM
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Bigg Gunz,
I have a question related to break-in for the new LT1 motor or any new GM motor for that matter. I understand if red tape issues prevent you from answering....
Do you whole-heartedly agree with the break-in procedure documented in the owner manual -- that is, the gentler take on a break-in -- or the more aggressive approach, such as with the use of a dyno or a similar high-load process?
I have a question related to break-in for the new LT1 motor or any new GM motor for that matter. I understand if red tape issues prevent you from answering....
Do you whole-heartedly agree with the break-in procedure documented in the owner manual -- that is, the gentler take on a break-in -- or the more aggressive approach, such as with the use of a dyno or a similar high-load process?