LS1 into a LS7???

[rohrt]

How close can an average Joe turn a LS1 into the 505 hp LS7? The reason I ask is that others on this site have asked about building a LSx motor with 500hp at the crank. I have the same thought in mind but I'm just not looking at slapping in a huge cam, I'm bent on efficency to. I would like to be able to drive cross country without worry. I know the LS7 has titanium rods and I'm not going that far, but I was wondering if the aftermarket has some of the parts to make it close. Can you get 427cid from a stroker kit, 11 to 1 compression with someones aftermarket heads and a equivilant cam? Just dreaming outloud right now.

[baz67]

The two blocks are incapatable. In other words you just cannot throw a LS7 rotating assembly into a LS1 because of the bore and stroke of the LS7.

Spend some time on lst1tech.com and you will find many streetable ways to get 500hp from a LS1.

[Steve1968LS2]

Yes, if you spent enough money on an LS1 you could equal the performance of an LS7. It would even be easier with an LS2.

However, the LS7 will still have more "capability" for power growth due to it's extra cubes.

Most all the internal parts in a LS7 will not work with an LS1 like Brian said. 500hp from an LS2 is pretty much a cake walk, but an LS7 is about more than just it's peak power numbers.

[gEtyOpAPiOn]

Or You Could Get A Katech Short Block Budget Ls7 I Forgot The Price On It But Its Cheaper Than A Crate Ls7

[ss dave]

The Katech value 427 s. block is very impressive, beautiful and approx. $6300. It is a resleeved LS2. The crate LS7 is $14K, it is a different block than the LS2. You still have to bulid a short block into a complete engine. Either way 427 just sounds cool.

[formula]

like these guys said, it depends on how "ls7" you want it to be.

It's not that hard to get 500 hp from any of the ls boys...but there's a lot more to a 7 than just power.

[JEFFTATE]

I've read that it's easy to get 500hp out of any of the LS series engines. They respond very well to big cams, aftermarket heads,etc..

[WS6]

You can stroke an LS1, 6 or even 2 to 427 cuin. MTI in Houston might be the best people on this planet at doing that. It's not cheap for the motor or the supporting mods. Keep the supporting mods in mind with whatever you do. New injectors and high flow fuel pump are not cheap.

As for durability, if you check the other thread about 500hp made by Mr. Tate, if I am not mistaken, you will find nothing but durable builds listed. They are all mild builds as well. Well, in terms of street manners anyway.

The last build I listed with the AFR heads and 224/228 cam would be a great street combination and make good power throughout the powerband, not just top end. The only downside to that build is the valve springs will need to be replaced in the 40-50k mile range for peice of mind. MPG should still be mid 20s for that car. Keep in mind it's an FRC C5 with an M6 and 3.42s. ie it's lightweight and geared for the street. If you run an auto you will need gears and a stall with that cam. Those will kill you around town MPG. But the manners would be very nice and highway running would be fine.

And yes LS1tech.com has even more info that's worth reading.

[Steve1968LS2]

I've read that it's easy to get 500hp out of any of the LS series engines. They respond very well to big cams, aftermarket heads,etc..

http://www.popularhotrodding.com/tec..._modification/

[ss dave]

Yea Steve throw that in there. Can't wait to see chasis #'s-when will that happen? In the meantime what's your crank estimate with accessories?

[4MuscleMachines]

You can get an 427 short block with a real LS7 block (not resleeved LS2) setup for wet sump at Scoggin Dickey for $6299. The LS7 block is about 3 times more expensive due mainly to the billet main caps so that is a good price.

The LS2 block is priced at $995 and a bare LS7 block is $3195, so do the math.

http://www.ls1tech.com/forums/showthread.php?t=568894

[Steve1968LS2]

You can get an 427 short block with a real LS7 block (not resleeved LS2) setup for wet sump at Scoggin Dickey for $6299. The LS7 block is about 3 times more expensive due mainly to the billet main caps so that is a good price.

The LS2 block is priced at $995 and a bare LS7 block is $3195, so do the math.

And I believe Katech sells billet main caps for the LS2..

http://www.katechengines.com/street_...tail.php?id=29

[Steve1968LS2]

Yea Steve throw that in there. Can't wait to see chasis #'s-when will that happen? In the meantime what's your crank estimate with accessories?

well that was crank HP with no accesories.. I am only driving a power steering pump so how much could that be?

My balancer only weighs 4.5lbs.. I tried to keep drivetrain loss down. I might loose 18% or so.

[ss dave]

Like I might have said in another thread thats a great build. I was just curious how much you lose with accessories- I had no idea. I think I read somewhere that you can except around 15% loss with a manual tranny and 20%-25% with an auto. Not to stray from the main point of this thread but what do you lose in hp with an AC? Thanks

[Steve1968LS2]

25% is a bit high with an auto.. modern drivetrains are far more efficient and have less parasitical loss than the old school stuff. I was told once by a GM guy that it's closer to 12% for a manual and 18% for a auto in a modern car.

I don't know what AC costs, less than having your windows down according to Mythbusters.. lol

[rohrt]

I did some of my own research

http://www.popularhotrodding.com/tec...engine_review/



LS7 specs
4.125 bore
4.0 Strock
Crankshaft: forged steel
Connecting rods: forged titanium
Pistons: cast aluminum
Compression ratio: 11.0:1
Cylinder heads: CNC-ported aluminum; 70cc chamber volume
Exhaust: Hydro-formed tubular header
Valve size, intake (mm / in): 56 / 2.20 (titanium)
Valve size, exhaust (mm / in): 41 / 1.61 (sodium-filled)
Camshaft: hydraulic roller; 15mm (.591 in) lift (intake and exhaust)
Rocker arms: 1.8:1 offset (intake only)
Air intake: composite manifold with 90mm single-bore throttle body
Fuel: premium required. 91 octane minimum
Horsepower: 500 (373 kW) @ 6,200 rpm
Torque (lb-ft): 475 (644 Nm) @ 4,800 rpm
Engine redline(rpm): 7,000


CAM LIFT INT/EXH DUR @ 0.050 LOBE SEP
LS1 0.497"/0.498" 199/208 119
LS6 2001 0.550"/0.550" 204/218 117.5
LS6* LS2 0.525"/0.525" 207/217 116
LS7 0.593"/0.588" 211/230 TK
* 2nd design LS6


Component 2001 LS1 2001 LS6
Type Overhead valve, pushrod V-8
Block Cast aluminum, 107.1 lbs (48.6 kg)
Block Deck Height 9.24 in. (234.7 mm)
Bore x Stroke (in./mm) 3.90 x 3.62 /99.0 x 92.0
Cam Drive Chain
Camshaft Hollow steel
Combustion Chamber Volume 4.1 cu. in. (67.3 cu. cm)
Connecting Rods PF1159M steel, sintered, forged and shotpeened, 6.1-inches
Crankshaft Cast nodular iron with undercut and rolled fillets
Cylinder Head Aluminum, 2 valves/cylinder, 20.3 lbs (9.2 kg)
Displacement 346 cu in, 5665 cc, 5.7 L
Exhaust Manifolds Cast nodular iron
Firing Order 1-8-7-2-6-5-4-3
fuel injection sequential electronic fuel injection
Fuel Requirement Premium unleaded
Ignition Individual-coil, DIS (distributorless ignition system) with double-platinum-tipped spark plugs
Intake Manifold Composite, 15.9 lbs. (7.2 kg)
Lifters Hydraulic roller type
Main Bearing Caps Powdered metal
Rocker Arms Investment cast steel with a roller fulcrum but a standard tip
Valve Lift (Intake/Exhaust)(in.) 0.500/0.500 0.525/0.525
Valve Lift Duration(Intake/Exhaust)(degrees) 198/208 204/211
Output
Horsepower (hp @ rpm) 350 @ 5,600 385 @ 6,000
Torque (lb-ft @ rpm) 375 @ 4,400(manual)
360 @ 4,000(auto.) 385 @ 4,800
Redline (rpm) 6,000 6,500
Fuel Cutoff 6,200 6,600
Compression Ratio 10.1:1 10.5:1
Manufacturing Origin St. Catherines, Ontario
Total Dressed Engine Weight Auto. - 457.6 lbs. (208 kg);
Manual - 497.2 lbs (226 kg) 497.2 lbs (226 kg)

[rohrt]

Well after spending a bunch of time on the LS1 site. I'm just as confused as ever(still learning). Scope creep comes into the picture very fast making a reasonable build out of reach.

My options look like this.

1. Buy a LS1, buy lots of parts to get the HP where I want it. 383 would be the biggest I could go with a stroker kit down the road.

2. Spend more money on a LS2 and have a better base to work with. More cubes, better heads have the ability to go to a 402/408 combo. Very popular over there.

3. Stay with traditional pontiac

[rohrt]

This site is awsome to do comparisons. Thought I would share for those learning like me.
http://www.gmgoodwrench.com/GMPerfor...l.jsp?engine=2

[KHShapiro]

i kinda lost all hope of staying even slightly close to what i wanted to spend on my 427 build, things got out of hand quickly.
I did go for what i conside the best parts, and while not an "LS7" i feel very that this is a much better build and stronger engine.
BUT if i where to do it all over again i would either stay with a stock bore ls2 or the Katech valve short block 427
My build by the way totals over 24k, you could build a very stout and just as powerful set up for well under half of what i spent using less expensive parts that i am sure would work just as well.

[Tom Welch]

Well after spending a bunch of time on the LS1 site. I'm just as confused as ever(still learning). Scope creep comes into the picture very fast making a reasonable build out of reach.

My options look like this.

1. Buy a LS1, buy lots of parts to get the HP where I want it. 383 would be the biggest I could go with a stroker kit down the road.

2. Spend more money on a LS2 and have a better base to work with. More cubes, better heads have the ability to go to a 402/408 combo. Very popular over there.

3. Stay with traditional pontiac

The third option is probably the least expensive, ! am facing the same decision. Build my 428 poncho or go with an LSX motor. I know that efficiency and power potential is going to be better with an LSX, but at what cost? I can go with my really heavy 500lbft torque making 428 and do it for about 1500.00 total. The cost is lower and power output is similar although at a lower rpm range. Is there really a definite disadvantage other than weight?