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GM revealed back in late October the new engine for the new Corvette C7. Now this is the first I heard of it but it seems like GM has finally decided to do some research into how to improve the aging LSx line up. To start the new Gen 5 LT engine has had it's block revised. Instead of a cast iron block with 4 bolt mains it uses an aluminum 6 bolt main block. In addition the bore and stroke have been updated to provided 6.2L of displacement (4.06x3.62) and the addition of forged pistons and titanium rods from the OEM.

General Motors also redesigned the head, the most noticeable change is the change in intake/exhaust valve arrangement. The exhaust valve is now towards the front of the engine and the intake towards the rear (if that makes sense to you haha.) It also goes without saying they adapted the CNP system from the LSx engines to this LT1. The fuel system also had been revamped to include a direct port fuel injection that looks like it came straight from a Diesel engine. To me it looks like a cross between a High Pressure Common Rail (HPCR) and Electronic Unit Injector. Not to mention the fuel pump is now driven off the camshaft gear also like a diesel. The common rail pressure exceeds 2100 psi!!! And takes 65 volts to operate the injectors. GM claims this engine produces 450hp and 450 lb ft of torque.

It's been a while since GM has impressed me. It seems like for the last 15 years GM had just been recycling the same engine only adding a few extra cubic inches every few years. Personally I am curious as to how this engine will react to boost. Granted it has a 11.5:1 compression ratio. I know that most of you guys are avid anti-Chevy guys but the way I see it, it's always best to know ur enemy.

Here are some pictures:
<a href="http://s1179.photobucket.com/albums/x385/Stay_Unique_91/?action=view&current=7019D980-46BC-41A8-928C-7DB423A2CD86-5181-000004E69302BE47.jpg" target="_blank"><img src="http://i1179.photobucket.com/albums/x385/Stay_Unique_91/7019D980-46BC-41A8-928C-7DB423A2CD86-5181-000004E69302BE47.jpg" border="0" alt="Photobucket Pictures, Images and Photos" /></a>

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The fuel system also had been revamped to include a direct port fuel injection that looks like it came straight from a Diesel engine. To me it looks like a cross between a High Pressure Common Rail (HPCR) and Electronic Unit Injector.
Nice, DGI and conventional fuel injection. DGI is very similar to Diesel in the way it has an additional pump that runs off the camshaft to pressurize the fuel much higher. The downside for having DGI only is the excessive carbon buildup .. ( ask Toyota why theyre re-building engines at 30k miles - they blame it on piston rings ) .. the engines with DGI and fuel injectors do not have this problem and fuel economy is improved as well.
 

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Looks really complicated with lots of parts to break and small pieces that must be precisely aligned. I doubt the reliability of that engine will be very good.

The common rail pressure exceeds 2100 psi!!! And takes 65 volts to operate the injectors.
With numbers like these it won't last.

Customer: "My Corvette isn't running right"
GM Dealership: "We'll take a look at it. $200 please."
Customer: "Well, OK. Just don't do anything until you talk to me."
GM Dealership: "OK."

... 4 hours later.

GM Dealership: "Your spider vane regulator valve capacitor sensor isn't functioning. We need to take the engine apart to get to it. It'll be $15,000 + parts."
 

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Looks really complicated with lots of parts to break and small pieces that must be precisely aligned. I doubt the reliability of that engine will be very good.

GM Dealership: "Your spider vane capacitor sensor isn't functioning. We need to take the engine apart to get to it. It'll be $15,000 + parts."
Just like any other engine, I dont see any difference between this one and any newer Ford engine. GM has pretty good reliability in their LS and LT series engines ( except for the opti-spark hidden behind the water pump ) .. :rolleyes: At least it can pick up crank position almost immediately with quick startups.

Funny you mention the Fuel injection spider unit - last week I repaired one of these on a 98 Chevy Tahoe, 350 - had a misfire on #6, turned out one of the spiders was clogged at the poppet nozzle. Easy fix. :D Although I dont know why they call the V6 unit a spider also, it only has 6 legs instead of 8 .. makes for a clean engine setup though, no fuel injectors popping out everywhere its under the intake manifold cover.

At least its not like these new Mercedes .. you need some minor work done, step 1. Remove engine assembly ..

Quote:
The common rail pressure exceeds 2100 psi!!! And takes 65 volts to operate the injectors.

With numbers like these it won't last.
Nothing new if youve worked on a Diesel engine. Thats typical of what you see on the new Toyotas and Hondas about 50 volts. They switch voltages, 65 volts to initially open, @14 to hold.
 

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Discussion Starter #6
Coyote is still way more impressive to me.
I agree. The Boss Coyote is a more efficient motor by far. Better gas mileage and the same HP from a smaller displacement engine. I am waiting for the DI system for the Coyote engine.
 

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I don't consider a change in a materials from the OEM a big change and DI is the new marketing trend. The only reason the Coyote doesn't have DI is Ford figured a way to get most of the benefit at a fraction of the cost.

Reminds me of the Buick 215, if GM want's to keep up they need at least 4V if not OHC.
 

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Still an OHV 2v. Nothing new here.
 

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I don't consider a change in a materials from the OEM a big change and DI is the new marketing trend. The only reason the Coyote doesn't have DI is Ford figured a way to get most of the benefit at a fraction of the cost.

Reminds me of the Buick 215, if GM want's to keep up they need at least 4V if not OHC.
The Coyote heads are supposedly provisioned for DI injectors, they'd just need the proper machining. If/When Ford makes use of that, it's really game over.

Too bad there's no floundering British automakers to buy the LT1 tooling this time around:tongue:
 

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Never really cared for GM engines due to the fuel and ignition issues they have at times. Some of them are easy enough to work on though, but I still rather buy anything but a GM, performance wise they are the best bang for the buck and I can respect that, durability wise they are ok, not the strongest engine designs I have seen, don't get me wrong they will take abuse but some engines are built much better from their rival competitors, its just easy to build horsepower with GM though and for the price comparison of other motors hard to beat. I really want to see how this motor pans out in the future I am sure it will do just fine...

Daily driver wise I wouldn't buy one, I learned my lesson a long time ago, performance wise they are fun to play with, and GM has some nice body's to go along with them, I probably wont build a GM anytime soon but for fun and not under my expense why not.

It's all part of the game, I could really care less most americans prefer GM to Ford and Mopar but I wouldn't want everyone to march to the beat of the same drum because that would be plain boring, I wouldn't want to race against the same engine all the time either because that is just no fun. So reguardless of whatever the case may be my preference is my preference and I have reasons why and because I like to be different it works ever better to suit me.

I hope all 3 American manufacturers can continue to make even greater things that will make great power, fuel economy and dependability and if the Imports want to compete with that I say let them, it will only inspire better things in the future to come.
 

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Dang lots of haters on any GM ls motor. Doesnt make any sense to me. There is no cheaper motor to build sick, nasty horsepower on than ANY LS motor. The 4.8, 5.3, especially the 6.0, 6.2, 7.0...all of these motors are fantastic pushrod motors.

I often see people bashing an OHV motor because its old school. But tell me why GM hasn't ceased production? Because it works! the motors remain super easy to work on, super reliable, and not to mention they make great #s!

Dont get me wrong, I am a die-hard Mopar man, i grew up around my dad's Super Bee Charger and 6.1 Challenger, and I love Fords too, especially their revised motor line-up, but NOBODY can seriously deny that GM builds a reliable, easy and CHEAP to build motor.

I mean think about it...i can take a cam out of a 6.0, change the pushrod length and/or adjust the rockers and throw it in a 4.8. I can take the heads off of 5.3, port. polish, and mill them, throw a relatively small cam (228), all on a 6.0 truck motor and make 450 HP on a good tune. Add a blower and youre looking at 600 HP. Most importantly here is the TORQUE produced by an OHV motor. Who doesnt love torque?

http://www.performancetrucks.net/forums/forced-induction-159/ls-power-twin-76mm-turbo-4-8l-1200hp-still-going-485734/

Read this article...then tell me what you think of a GM motor.
 

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I guess I haven't experienced the reliability with them that I hear people talk about. I have reliably seen them leak oil, lol. But I agree they make good numbers for really cheap. I don't think we can say the only reason they haven't changed from OHV is due to the perfection of that engine, as we have to consider that they were also bankrupt not too long ago. They were pursuing OHC for a while, too, IIRC. Either way, they definately have their place, and have been a good engine for them; much better than the Northstar Engines....

As far as torque, from what I've seen, the coyote has a pretty nice torque curve... how does it compare to a 5.3 or 6.0 LSx torque curve (serious question)?

Stephen
 

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My old 4.8 truck has 245,000 miles on it. No valve noise, no lifter taps...nothing...smooth as silk at a quiet 500 RPM idle :) But guess what...oil leak all around the pan gasket, about a drop a day.

Apples to apples now come on...5.3 and coyote are totally different beasts. No comparison, hands down the Coyote is a brute that honestly no other American production NA V8 small block, except maybe the LS7, can touch.

Im curious of the torque curve too, in fact dont the blown 5.4 2v make a TON of torque...disproving my statement?
 

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I was responding to the "Torque by an OHV" comment. I was just stating that the Coyote (and even the 5.4) have some decent torque low end as well. But as was stated, the LS engines have their place and have been a good engine for GM.

Stephen
 

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I raise the BS flag on cheap. Once you start put real performance upgrades on any engine they are all roughly the same price. By that I mean exceed OEM and not OEM or OEM replacement.

As far as reliability the LS series is running on the edge, hence the reason for VVT, cylinder management and lighter chaises.

GM has fallen behind but they are afraid of change. So they will increase CID for power and gimmicks to make up for the mpg hit.
 

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"Instead of a cast iron block with 4 bolt mains it uses an aluminum 6 bolt main block" 8,500+ rpm's? :tongue: only thing that impresses me is the power the ls motors make while still being a pushrod..
 

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I wouldn't say they're running on the edge, there's a lot of potential to grow with that kind of displacement, hence why they are so responsive to cam and bolt ons. LS motors and the new LT1 are still relatively "lazy" on a global stage. There's lots of unused cubes.

I don't see what the problem is with lighter chassis either. Newer performance cars keep getting more and more powerful, to legitimately stupid levels in some cases, but the cars the engines are going into keep getting bulkier and heavier.

But tell me why GM hasn't ceased production?
Circumstance.

When the LS series would have been under development (early-mid 90s) gas was cheap and pushrods were still a very common valvetrain at the time for V8s outside of Italy and Germany. And the latter really only used them for smoothness and refinement more than anything(which was also the real intent for the early mod motors as well). GM dumped in enough money to need to keep it around for a while.

More to the point though, GM today hasn't ceased LS production for the same reason ford kept the 4.6 and 5.4 2Vs around so long. It's been their only V8s, they work just fine in trucks and without them the Corvette would, ipso facto, cease to exist and there'd be executives burned at the steak because of it. Developing a true engineering marvel from scratch just isn't and hasn't been in the cards for GM of late. The Corvette ZR1 is case and point. Remember the original? Basic SBC architecture but with Lotus designed DOHC cylinder heads? That motor produced the same numbers as a contemporary Ferrari Testarossa did, purely N/A. The new one? They had to Strap a blower on it to match the exotics. That was a penny pinching admission of futility if I ever saw it. In fact I did, since Ford/SVT engineers openly admit to that reasoning for the 03 Cobra's genesis!

That said, I don't dislike the LT1. It's a modest evolution of the LS platform, and that's just fine but constantly hearing it bolstered from GM fans as "the pushrod underdog that laughs in the face of its high tech competition" just wears on me. It's as powerful and torquey as it is because it has cubes the competition doesn't. Nothing magical and little to do with pushrod vs. OHC.
 

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Wait; I came to this thread late.

Oscar's doing an LT1 swap now? What?

He'll never get 10k rpms out of that...

:confused:

(lol)
 
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