Newbie with an LS9 Engine

[Smokin Sam]

My name is Sam and this is my first post here. Nice to see a site like this with all the resources and knowledge. I am a motorcycle mechanic by trade but I am just learning about my Chevy. It is a 2wd 1970 3/4 ton with less than 150,000 miles on it. It has a 411 diff and a 3 spd auto in it. I'd like to find out a little more about the engine. It is the original LS9. It now has E ignition, Edelbrock intake and 600cfm, with a mild comp cam and freshly ground crank (4 bolt) and first OS pistons. The heads are reconditioned but stock. It pulls hard but what kinda power does this thing really make?

[JOJABOY]

Not sure about the power a LS9 makes. But am curious as to how that 3spd transmission is at 100kph? Are your RPM's pretty high? With 4.11:1 gears in the rearend, I would probably want and overdrive transmission behind that LS9.

[JOJABOY]

Not sure which LS9 you have.

The original LS9 was a 350 cu in V8, developing 160 hp and 245 Ft/lbs of torque.

The Gen IV LS9 is a supercharged 6,162 cc (6.162 L; 376.0 cu in) engine, based on the LS3; the LS7 block was not used due to the higher cylinder pressures created by the supercharger requiring the thicker cylinder walls of the LS3. Cylinder dimensions are now 4.06 in (103 mm) bore and 3.62 in (92 mm) stroke. It is equipped with an Eaton four-lobe Roots type supercharger and has a compression ratio of 9.1:1. Power output is rated 638 bhp (476 kW) at 6500 rpm and 604 lb·ft (819 N·m) at 3800 rpm.

[Smokin Sam]

Haha, I wish mine was supercharged! It's the original 1970's version.

[Special-Ed]

Originally Posted by JOJABOY

Not sure which LS9 you have.

The original LS9 was a 350 cu in V8, developing 160 hp and 245 Ft/lbs of torque.

The Gen IV LS9 is a supercharged 6,162 cc (6.162 L; 376.0 cu in) engine, based on the LS3; the LS7 block was not used due to the higher cylinder pressures created by the supercharger requiring the thicker cylinder walls of the LS3. Cylinder dimensions are now 4.06 in (103 mm) bore and 3.62 in (92 mm) stroke. It is equipped with an Eaton four-lobe Roots type supercharger and has a compression ratio of 9.1:1. Power output is rated 638 bhp (476 kW) at 6500 rpm and 604 lb·ft (819 N·m) at 3800 rpm.

Am I understanding you right. I'm too lazy for google with my iPhone. A modern ls3 with a supercharger is over 600 horses.

The factory crate ls3 I'm gonna put in a 2 wheel drive k5 is something like 420 horse with the factory tune ECM

So when I get bored and throw in a supercharge I'm gonna gain 200 horse. I haven't even looked at the specs but I was guessing 100 horse.

I've been out of the hot rod world for a long time. What gm rear end is gonna hold up to that? Or do I just go with the ford 9" and call it a day.
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[Spokanistan]

Originally Posted by Special-Ed

Am I understanding you right. I'm too lazy for google with my iPhone. A modern ls3 with a supercharger is over 600 horses.

The factory crate ls3 I'm gonna put in a 2 wheel drive k5 is something like 420 horse with the factory tune ECM

So when I get bored and throw in a supercharge I'm gonna gain 200 horse. I haven't even looked at the specs but I was guessing 100 horse.

I've been out of the hot rod world for a long time. What gm rear end is gonna hold up to that? Or do I just go with the ford 9" and call it a day.
Posted via Mobile Device

Not just any ls3 it had some improvements before the supercharger, but yes the ls9 puts out I believe around 630 hp but don't quote me, just look up the current corvette zr1, the c7 zr1 is rumored to pass 700 hp. Sorry for getting off topic.
Posted via Mobile Device

[Spokanistan]

Originally Posted by Special-Ed

Am I understanding you right. I'm too lazy for google with my iPhone. A modern ls3 with a supercharger is over 600 horses.

The factory crate ls3 I'm gonna put in a 2 wheel drive k5 is something like 420 horse with the factory tune ECM

So when I get bored and throw in a supercharge I'm gonna gain 200 horse. I haven't even looked at the specs but I was guessing 100 horse.

I've been out of the hot rod world for a long time. What gm rear end is gonna hold up to that? Or do I just go with the ford 9" and call it a day.
Posted via Mobile Device

Not just any ls3 it had some improvements before the supercharger, but yes the ls9 puts out I believe around 630 hp but don't quote me, just look up the current corvette zr1, the c7 zr1 is rumored to pass 700 hp. Sorry for getting off topic.
Posted via Mobile Device
Posted via Mobile Device

[Smokin Sam]

I've heard talk about 325 hp 350's, I was hoping it was one of them. My wife's Z-24 makes 165 lol.

[mmiddle]

Originally Posted by Smokin Sam

My name is Sam and this is my first post here. Nice to see a site like this with all the resources and knowledge. I am a motorcycle mechanic by trade but I am just learning about my Chevy. It is a 2wd 1970 3/4 ton with less than 150,000 miles on it. It has a 411 diff and a 3 spd auto in it. I'd like to find out a little more about the engine. It is the original LS9. It now has E ignition, Edelbrock intake and 600cfm, with a mild comp cam and freshly ground crank (4 bolt) and first OS pistons. The heads are reconditioned but stock. It pulls hard but what kinda power does this thing really make?

You are looking at around 275-290ish. The HEI makes a big difference on power. The stock engines really did not have much power by todays standards. Adding stuff like a lumpy roller cam, better heads, roller rockers intake and headers help bring it up, but pushing up over 400HP kills the mileage and takes it out of the daily driver category. That is why so many of us go with an LSx mill. 400+ out of a stock engine with great fuel mileage.

And yes the LS3 does make over 400hp.The LS3 E-rod is rated at like 420, the LSA makes over 500 and the LS9 makes well over 600. All with great drivability and reliability.

[Smokin Sam]

It feels more like that kinda HP despite what it looks like.

http://[URL=http://s824.photobucket.com/user/SmokinSam/media/MasterBateson002.jpg.html][/URL]