LT1 versus the competition
10-25-2012, 07:40 AM
#22
Burning Brakes
Hmmmm ... Looks like this one is heavily biased toward emissions and fuel economy. I'm sure it was a huge challenge to add all the new tech and hardware and still get a power bump over the LS3. Here are the stats that jump out at me.
14 HP more than the LS3, not even close to the LS7 as many had speculated.
A gain of 1 MPG????? WTF???
Heavier than the LS3
Lower redline limit than LS7
Very ugly valve covers. This one looks harder to mod and dress up. I'm sure some enterprising companies will figure out how to unfugly that thing. This motor fell out of the Fugly Tree and hit every branch on the way down.
The guys at FAST must still be partying. They are going to sell a ton of intakes for this motor!
I will be keeping my Z06
14 HP more than the LS3, not even close to the LS7 as many had speculated.
A gain of 1 MPG????? WTF???
Heavier than the LS3
Lower redline limit than LS7
Very ugly valve covers. This one looks harder to mod and dress up. I'm sure some enterprising companies will figure out how to unfugly that thing. This motor fell out of the Fugly Tree and hit every branch on the way down.
The guys at FAST must still be partying. They are going to sell a ton of intakes for this motor!
I will be keeping my Z06
10-25-2012, 08:18 AM
#24
Team Owner
The lower photo shows a PD supercharged engine with a dry sump. Notice no dip stick or oil filler cap on the valve cover. Also notice what appears to be a belt driven oil pump(or maybe the innercooler coolant pump).
Last edited by JoesC5; 10-25-2012 at 09:05 AM.
10-25-2012, 11:28 AM
#27
Race Director
10-25-2012, 11:33 AM
#28
Le Mans Master
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The thing I noticed about the two keeks cad drawings above is that one has a dipstcik and the other does not. So the larger photo is a dry sump version of the engine.
I cannot tell if it is turbo charged or supercharge although there is some writing on the center cover. There is also an extra tube accross the front of the engine. It is small. I think you can see the scavenge pump on the bottom driver side of the engine.
I cannot tell if it is turbo charged or supercharge although there is some writing on the center cover. There is also an extra tube accross the front of the engine. It is small. I think you can see the scavenge pump on the bottom driver side of the engine.
10-25-2012, 02:50 PM
#29
Team Owner
The thing I noticed about the two keeks cad drawings above is that one has a dipstcik and the other does not. So the larger photo is a dry sump version of the engine.
I cannot tell if it is turbo charged or supercharge although there is some writing on the center cover. There is also an extra tube accross the front of the engine. It is small. I think you can see the scavenge pump on the bottom driver side of the engine.
I cannot tell if it is turbo charged or supercharge although there is some writing on the center cover. There is also an extra tube accross the front of the engine. It is small. I think you can see the scavenge pump on the bottom driver side of the engine.
10-26-2012, 03:40 AM
#30
Le Mans Master
10-26-2012, 10:31 AM
#32
Le Mans Master
10-26-2012, 12:10 PM
#33
Race Director
I thought I would put together a comparison of the LT1 versus some similarly sized V8s from around the world.
GM LT1 - 6.2L, 16v, pushrod, 103.25 mm x 92 mm, 11.5:1 compression, DI, VVT, DOD, 450+ hp, 450 lb-ft
Ford Boss - 6.2L, 16v, OHC, 102 mm x 95 mm, 9.8:1 compression, VCT, 411 hp, 434 lb-ft
Dodge 392 Hemi - 6.4L, 16v, pushrod, 103.9 mm x 94.6 mm, 10.9:1 compression, VCT, DOD, 470 hp, 470 lb-ft
AMG 6.3 - 6.3L, 32v, DOHC, 102.2 mm x 94.6 mm, 11.3:1 compression, VCT, 518 hp, 465 lb-ft
GM LT1 - 6.2L, 16v, pushrod, 103.25 mm x 92 mm, 11.5:1 compression, DI, VVT, DOD, 450+ hp, 450 lb-ft
Ford Boss - 6.2L, 16v, OHC, 102 mm x 95 mm, 9.8:1 compression, VCT, 411 hp, 434 lb-ft
Dodge 392 Hemi - 6.4L, 16v, pushrod, 103.9 mm x 94.6 mm, 10.9:1 compression, VCT, DOD, 470 hp, 470 lb-ft
AMG 6.3 - 6.3L, 32v, DOHC, 102.2 mm x 94.6 mm, 11.3:1 compression, VCT, 518 hp, 465 lb-ft
I know Jinx is familiar with that concept, don't know robvuk well enough to have a clue what he meant.
What am I missing here, other than possibly some intentional word play?
Last edited by tuxnharley; 10-26-2012 at 01:46 PM.
10-26-2012, 03:12 PM
#36
Le Mans Master
Not sure if you guys are serious here, just kidding around, or trying to pull someone's chain, but - WTF are you guys saying??? HP/liter - hello? Is that not both a common and relevant measure of comparison?
I know Jinx is familiar with that concept, don't know robvuk well enough to have a clue what he meant.
What am I missing here, other than possibly some intentional word play?
I know Jinx is familiar with that concept, don't know robvuk well enough to have a clue what he meant.
What am I missing here, other than possibly some intentional word play?
http://forums.corvetteforum.com/c7-g...post1582159513
I get that horsepower/liter can be relevant in some contexts, especially to engineers interested in specific combustion efficiency separate from what it takes (and costs and weighs and requires space for) beyond the actual volume swept by the piston to achieve it. But all too often people focus on this metric to the exclusion of all else, generally with the specific misguided intent of slamming pushrod engines and the Chevrolet smallblock and the Corvette in particular. Practical matters of the engine as a whole and how it contributes to the vehicle that gives it purpose, both the power it delivers and what it requires, must not be ignored if one is trying to understand and compare the value of a powertrain or a sports car.
.Jinx
10-26-2012, 04:01 PM
#37
Le Mans Master
Not sure if you guys are serious here, just kidding around, or trying to pull someone's chain, but - WTF are you guys saying??? HP/liter - hello? Is that not both a common and relevant measure of comparison?
I know Jinx is familiar with that concept, don't know robvuk well enough to have a clue what he meant.
What am I missing here, other than possibly some intentional word play?
I know Jinx is familiar with that concept, don't know robvuk well enough to have a clue what he meant.
What am I missing here, other than possibly some intentional word play?
Think about it this way. If you could have an engine that has 1000hp, takes up the space of a 15" cube and weighs 100 lbs. and got great mileage, would you care if it used pushrods or how many valves and cubic inches the internals are?
Last edited by robvuk; 10-26-2012 at 04:04 PM.
10-26-2012, 04:40 PM
#38
Drifting
I agree hp/L means nothing on the street. Hp/tq curves matter most to me, then engine physical size, then displacement.
Hp/tq is for the engineers to figure out and brag. They are given a set of initial goals. If say, the first prototype engines were indeed a 5.5 build, but they could not reach 470hp, then they pick a different engine build. In this case the 6.2 with a 6600rpm redline was obviously enough. Had it not been, we just as easily could have been looking at a 6.5L engine(or even a 377ci-ish engine!) but the goals were met. Had the goals not been achievable, we also could have been looking at some new dohc engine.
That being said, does anyone else think 60lbs over the ls3 sounds a bit extreme? I mean, how much does the direct injection system really weigh. I immediately thought 60+lbs was ridiculously high. While it's still not as top heavy as a dohc v8, its mass, part of the joy of swapping it into other cars, makes other engines look not nearly as bad as the LSx did. Bmw's v8 I remember reading awhile back was the lightest production dohc v8 at I believe 448lbs. Wether that's true or not I dunno, but I know of a couple other engines right around the LT1's weight, like Ford's 4.6 and 5.0.
Hp/tq is for the engineers to figure out and brag. They are given a set of initial goals. If say, the first prototype engines were indeed a 5.5 build, but they could not reach 470hp, then they pick a different engine build. In this case the 6.2 with a 6600rpm redline was obviously enough. Had it not been, we just as easily could have been looking at a 6.5L engine(or even a 377ci-ish engine!) but the goals were met. Had the goals not been achievable, we also could have been looking at some new dohc engine.
That being said, does anyone else think 60lbs over the ls3 sounds a bit extreme? I mean, how much does the direct injection system really weigh. I immediately thought 60+lbs was ridiculously high. While it's still not as top heavy as a dohc v8, its mass, part of the joy of swapping it into other cars, makes other engines look not nearly as bad as the LSx did. Bmw's v8 I remember reading awhile back was the lightest production dohc v8 at I believe 448lbs. Wether that's true or not I dunno, but I know of a couple other engines right around the LT1's weight, like Ford's 4.6 and 5.0.
10-26-2012, 06:09 PM
#39
Team Owner
Hp/tq is for the engineers to figure out and brag. They are given a set of initial goals. If say, the first prototype engines were indeed a 5.5 build, but they could not reach 470hp, then they pick a different engine build. In this case the 6.2 with a 6600rpm redline was obviously enough. Had it not been, we just as easily could have been looking at a 6.5L engine
At one point I had thought that there was a chance that the base car could get a 6.4L or 6.5L engine...and there is still a chance that a future model (Z06? ZR1?) Corvette C7 could include a higher displacement version of this LT1 as well. 
I'd heard that it was roughly 40 pounds heavier but not a full 60.
And yes it does sound a bit high.
10-26-2012, 06:18 PM
#40
Le Mans Master
A big reason for the Corvette smallblock's efficiency is the fact that it's in a very slippery and lightweight package. (Yes, some of that package is allowed by the engine architecture, but a lot of it isn't.)
We might draw some efficiency conclusions about engines in cars to which Corvette is very closely matched like 911 but it starts to get sketchy beyond that.
.Jinx