Rumor has it that the V8 engine being developed to power the forthcoming Chevrolet Corvette ZR1 (C7) will be called “LT5”, partly because it’s one digit greater than the supercharged LT4 that powers the current Z06, and partly as a nod to the Lotus-engineered DOHC LT5 V8 that powered the original ZR-1 from 1990 through 1995.
More likely than not, that rumor will turn out to be true; new photographic evidence from dealer Rick “Corvette” Conti appeared this morning, showing a closeup of an engine cover with “Corvette LT5” stamped into it. And no, it doesn’t look like anything that was on the original LT5 on the C4 ZR-1.
Specifics regarding the forthcoming LT5 engine are still shrouded in mystery, with some rumors maintaining it’ll be a higher-output, supercharged pushrod V8 like the LT4, and others claiming it will be a brand-new dual-overhead-cam V8 like the LT5 of yesteryear. The first possibility is supported by the results of an RPO code search, claims Weapon X Motorsports, while the latter is based on some supposedly leaked internal documents from General Motors.
A dual-cam V8 with four valves per cylinder would be a more modern, sophisticated powerplant – characteristics that befit the ZR1 name. But on the other hand, another supercharged, cam-in-block engine with some tweaks and a bump in power would be the easier route. Your guess is as good as ours.
Comments
Is it just me or does that image look like it was Photoshopped ~ poorly?
I might be super optimistic but I’m guessing the LT5 is a DOHC 6.2 SC 750hp, and propels the ZR1 to a top speed a 220 mph. One can hope right?
PSSSST! Mercury Marine….
I just want to see this beast already! We’ve been teased with reveal dates for almost a year!! With the mid engine panels already being leaked and this car on the verge of being unveiled? Corvette is about to be the real envy of a lot of supercars
LT5= 6.2 liter OHV V8 engine SC. LT6:: Na DI/PI DOHC V8 engine (5.5 or 5.2 liter). LT7:: TT V8 engine DI/PI DOHC (5,2 or 5.5 liter).
Let’s reserve the LT7 designation for the 7.0 liter please, GM, please.
Cam-in-block or DOCH, how ever you see it, GM!
The numbers in the LS# or LT# engine RPO codes do not correspond to the engine displacement.
Since the latest iteration of the “LS” family, it has! The gen3 V8 was an entirely new architecture for the engine family (as you surely do know) and the LS7 (gen4) was an evolutionary step forward. As for the rest of the LS/LT family RPO codes, no.
Though they did just miss on the LS6 which was an improved casting and material version of the (gen3) LS1 5.7 liter. The 6.0 liter with an aluminum block didn’t come out until 2005, (gen4 family).
GM coulda, woulda, shoulda called the LS6, the LS2 and vice versa. Or maybe the wanted the new LS7 to be special, like the Corvette 427, the only C6 convertible with the “LS7” I do believe?
“GM coulda, woulda, shoulda called the LS6, the LS2 and vice versa. Or maybe the wanted the new LS7 to be special, like the Corvette 427, the only C6 convertible with the “LS7” I do believe?”
Or maybe GM has internal reference codes their engineers use to differentiate between the countless variations over 5 different block generations (SBC, LTmk1, LSmk1, LSmk2, LTmk2), and you’re overanalyzing the RPO codes looking for patterns when there really isn’t any.
In fact, there’s a name for what you’re doing. It’s called ‘pareidolia’.
https://en.wikipedia.org/wiki/Pareidolia
“Or maybe GM has internal reference codes their engineers use to differentiate between the countless variations over 5 different block generations”
Why yes, they do, as you, surely know. Just like software, where the revisions go 3 and 4 dots (.) deep. But Microsoft, Apple or any other developer does not name their software Windows 7.xxx.xxx.xx or OS 11.xxx.xxx.xx, those refer to revisions or “internal reference codes” or the “countless variations” of development. What they ultimately sell to you and I is Microsoft Windows “LS7”.
“coulda, woulda, shoulda” is just a little humor, do you ever come up for air from your “overanalyzing “, that “is of no use to dwell on” to experience humor Doc.?
https://www.urbandictionary.com/define.php?term=shoulda%20coulda%20woulda
Lighten up, this isn’t an engineering forum. GM vary well could have done (at any time, if they wanted to). Something similar to what BMW has done where their model numbers refer to engine size. Is not the gen3 LS7 a 7.0 liter?
Humor me, just don’t overanalyze it!
“Is not the gen3 LS7 a 7.0 liter?”
There was no Gen3 LS7. The LS7 is a Gen4 block.
I’ll go further. The LS2 and the LS4 were 6.0L and 5.3L respectively. The number in their RPO codes doesn’t reflect their displacement, nor does the 7 in LS7.
What’s there to overanalyze? The numbers mean nothing, but you WANT it to mean something. It just doesn’t work that way, and never has.
TYPO “gen3 LS7” Yes it is a gen4 which I stated in my previous post. As for the LS2 and the “LS6”.
I never said anything about the “LS4”.
That was “your typo”, that was you (I guess it’s professor RPO not Doctor RPO) scalding some other student here about LS/LT numbers having nothing to do with HP.
My point with the LS6 (5.7 liter) was that they already had a cast iron 6.0 liter and could have used the “LS6” designation on an aluminum block performance motor.General Motors can do whatever the hell they dam well please, or not!
And I think you are completely wrong if you think the 7 wasn’t use purposely on the LS7, professor, now may I be expelled so I can get back to my beer?
“And I think you are completely wrong if you think the 7 wasn’t use purposely on the LS7, professor, now may I be expelled so I can get back to my beer?”
Before you go and enjoy your weekend, there is a 1500 word essay due Monday on the meaning of the word ‘coincidence’ and how easily someone can become confused and mislead by thinking of a coincidence as an example of pareidolia.
I know it’s hard for you to take it that way, but the 7 in LS7 is coincidently related to the engine displacement, not directly related.
Double spaced, 1″ margin throughout, 12pt Times New Roman. Use may use contractions but don’t exclude them because you have an irrational fear of apostrophes. Oxford commas and single spaces after periods are mandatory, and don’t use extraneous “quotes” around random “words” in your text that serves as a weak “attempt” to provide “emphasis”.
And yes, it’s Dr. RPO (B.Eng, BEDS, MArch, RPO.Eng) to you.
“Let’s reserve the LT7 designation for the 7.0 liter please, GM, please.
Cam-in-block or DOCH, how ever you see it, GM!”
That little phrase is what you are hung up on Mr. architect.
LET IT GO, you nor I have proof of or against “coincidence” or otherwise.
7.0 liters and a 7,000 RPM redline?
No proof of said (B.Eng, BEDS, MArch) either, but it doesn’t really mater does it?
“7.0 liters and a 7,000 RPM redline?”
Yes, that’s also a coincidence. They happen more often then you think.
See? You’re seeing 7’s everywhere. You ARE suffering from pareidolia.
Did you know that the your previous comment response hash ID was #717443? There’s two 7’s in the comment ID, but that doesn’t mean the 7 in an LT# RPO code refers to the engine displacement.
You better not step outside or you might see more 7’s.
HAH. LMFAO. There’s a 1 two 4’s and a 3 in that ID also. Wonder what that could mean. There truely is a forest in those trees maybe?
Ever been to the forest? I have, Flagstaff AZ. There’s another 7 in there somewhere. See if you can find it!
LET IT GO.
How do you like these specs?
http://www.mercuryracing.com/automotive/
Make sure you put a plastic over your keyboard or the drool will clog your keys. Lol
Horsepower
750 (559 kW)
RPM
8000
Compression Ratio
11.7:1
Power (HP(kW)
750/559 @ 8000 rpm
Cylinders/Engine Configuration
V-8, 32-Valve Double Overhead Cam (DOHC)
Valve Actuation
Shaft Mounted, End Pivot Finger Follower with Mechanical Lash Adjustment
Displacement (CID/L)
428/7.0
Bore (in/mm)
4.125/104.775
Stroke (in/mm)
4.0/101.60
Compression Ratio
11.7:1
Induction System
Naturally Aspirated with Twin Electronic Throttle Bodies
Fuel System
Sequential Port Fuel Injected (SPFI)
Fuel Requirements
Unleaded 91 Octane (R + M/2)
Ignition System
Individual Coil on Plug, with Integrated Drivers
Recommended Alternator
165 Amp (2327 Watt) GM Powermaster P/N 58247
Controller
Mercury Racing PCM
Cooling System
Water Cooled with 160-degree (71 C) Thermostat
Lubrication System
Wet Sump w/Modified Holley 302-1 Pan, GM High Volume Oil Pump
Oil Requirement
Premium Synthetic 15W-50 for warm weather use HP1 or HP4 Equivalent
Oil Capacity With Filter (qts/L)
6.5/6.2 (without filter)
Transmission
Engine is Capable of Operating with Customer Supplied Manual or Automatic Transmission
Length (in/mm)
27.1/688
Width (Across Timing Belt Cover) (in/mm)
30.27/769
Width (Across Rear of Heads) (in/mm)
29.1/740
Height (in/mm)
17.1/435
Can they warrant it for 100k?
Warranty 1 year with no mileage restriction same as GM or Ford crate engines.
I suspect with the leaks that the ZR will hit Detroit in January and production in late January.
Right now if I had to take a stab at it the LT 5 is DOHC and supercharged. It appears in the ZR1 and moves to the C8.
GM rarely puts a new engine in a new Vette at the same time. The L88 was in 67 and moved to the 68 C3. The tune port came a year after the one year crossfire C5.
Just call it a hunch.
The photo here is not a random leak just as the others of late. This is the lead up to Detroit.
If GM did not want these cars seen they would not be at Mc Donald’s.
Note too GM had a LT5 before. It too was a DOHC engine. Corvette tries to keep some heritage ties.
If the picture ‘CORVETTE LT5’ is accurate then there has to be a reason and it’s got to mean MORE performance than the LT4 because if it was just a refreshed LT4, Chevy could have just borrowed a page from Intel and called the engine a LT4-R; but calling it a LT5 supposedly should distinguish the engine and possibly mean a major jump in performance over the current LT4 engine and elevate the C7 Corvette ZR1 to a new standard in performance that no other Corvette had ever achieve (unless this is a limited production vehicle, the C7 Corvette ZR1 is a car every fan of the Corvette should want to own).
Not necessarily. The difference in numbering from LT4 to LT5 doesn’t always mean more power. It’s simply one number that describes 2 different engines that share a common block (Gen V).
The LS2 had 400hp, but the LS4 had 303hp. Both were Gen IV blocks, but the numbering of their RPO code told you nothing about how powerful they were relative to one another.
Yea, while Chevy car sales suffer we’ll always have 10,000 versions of the Duschette for $90,000+. Drop that engine in an mass-production Alpha Impala and now were talkin
The original ZR1 was not 1990 to 1995. The original ZR1 was a 1970 Corvette with a 350 LT1. No air conditioning , power steering, or automatic transmission. With the Muncie M 22 and 4.10 rear end 0 to 60 was about six seconds. Quarter mile time was 14.1 at 102 miles an hour. 47 years ago that was impressive.
True but the 90’s used a LT5 DOHC engine. There could be a connection.
A limited release in the C7 would make sense before the C8.
Developed by Mercury Marine, amazing how that motor and the Vipers V10 were so close in HP through those years.
Trivia, what has 7 liters and a 7k RPM redline?
What really killed it was GM charged a premium and then moved to a new cam in block with more power and torque.
GM really kind of boxed themselves in on this deal.
Neat engine just really bad timing.
Get over it GM…………………..come up with a new series of identity for this last blast of an Icon from the 70’s…..! Is this the best GM can come up with??????? These ZR-1 cars will drop in value & demand like the previous years ( look at the $$$$ numbers ) The fact that GM in their wisdom, chose to supercharge the Z-06 on the C7… where is the benefit ???? Time for some ingenuity!!!!
“The fact that GM in their wisdom, chose to supercharge the Z-06 on the C7… where is the benefit ????”
The benefit is in better performance numbers.
That might be the dumbest thing I have ever read!