Horsepower question

**MM2364** · 03-15-2012, 04:12 PM

Hello everyone, I have read this forum for a while but this is my first post.

I have a 1966 Chevy II SS. I decided to put it on an after market full frame (Schwartz Performance) and doing a LS1/LS6 swap while I'm at it. I already bought this motor but I still would like some opinions before I finish the whole project. This will not be a drag car but one that will be able to go fast, stop and turn. (i hope) I want it to start and be able to drive it anytime anywhere.

I bought a 2000 camaro 5.7 LS1 short block stock lower end with flat top pistons and it has LS6 heads and intake with polished 100mm throttle body. I have been told it will make between 450-475 HP but I want to push it past 500 HP if I can.

Block= Aluminum 346 CI 3.899 bore X 3.622 stroke
Cam= comp XR275HR hydraulic lift 275/277 duration, 0.566/0.5685 lift and 112 seperation.
Heads= Patriot unknown which one with 65.5 CC chambers
compression is 10.9 to 1
42 pound injectors
Stock ported LS6 intake (note having issues with rail mounting brackets)
Howell tuned CPU and harness
Fast fuel rails
Aeromotive regulator and fuel pump A-1000
MSD coils
Stock Camaro accesories (water pump, a/c, p/s.)

This motor is still in my garage and the frame is being painted before it all goes together. The motor will go in front of a T56 6 speed with McCloud double clutch, new steel flywheel.

My question is how much HP do you think I have and what is thye best way to get past 500+ without a turbo or blower.

Thanks for your input

Joe

**mark21742** · 04-02-2012, 06:21 AM

That's a pretty small cam (222/224) is step up to something like a 228/23x cam, maybe shave some more off the heads to bump the compression up a little more.

You said flat top pistons, but to they have valve reliefs cut in them? If you do mill and go with a bigger cam you will need to check your piston to valve clearance.

From what I have found through a lot of reading and searching 8.5:1 dynamic compression is about max for 92/93 octane gas, so depending on cam you might be able to go as much as 11.5:1 static compression. (I'm running 12.5:1 scr, but my big cam drops my dcr down to 8.22:1).

Also if you have the space above the valley pan +11" you can buy an Edelbrock proflo xt intake and port the hell out of it like I did and get a lot broader power band and higher peak rpm than with a stock style aftermarket intake for the ls motors. I paid $365 new for mine and was worth every penny

**MM2364** · 05-21-2012, 10:11 AM

Originally Posted by mark21742

That's a pretty small cam (222/224) is step up to something like a 228/23x cam, maybe shave some more off the heads to bump the compression up a little more.

You said flat top pistons, but to they have valve reliefs cut in them? If you do mill and go with a bigger cam you will need to check your piston to valve clearance.

From what I have found through a lot of reading and searching 8.5:1 dynamic compression is about max for 92/93 octane gas, so depending on cam you might be able to go as much as 11.5:1 static compression. (I'm running 12.5:1 scr, but my big cam drops my dcr down to 8.22:1).

Also if you have the space above the valley pan +11" you can buy an Edelbrock proflo xt intake and port the hell out of it like I did and get a lot broader power band and higher peak rpm than with a stock style aftermarket intake for the ls motors. I paid $365 new for mine and was worth every penny

Thanks for the advise/information.

**0rion** · 05-21-2012, 11:43 AM

it sounds to me like what you want is clashing with your goals. 500 to the wheels on a stock cubed LS1 will take a lot. Also, with your current set up I'd have to see 450 at the wheels to believe it. That seems pretty generous to me for those heads and that cam. The set up you have now should run pretty strong and be a good driver....I would probably wait and see what you have there before doing anything unless you're wanting to do it all out of car before putting the motor in. 500 to the wheels and you'll definitely need new/better heads and a large cam.....very large.

***SMWS6TA*** · 05-21-2012, 12:34 PM

Only way with that setup to reach 500 is by spray. Otherwise you'll need a LS2 OR 3 to get there without a FI setup

**2002ssslp** · 05-21-2012, 02:41 PM

Toss a 100 shot of NOS on and call it done !

**BrownsMillsAntz** · 05-24-2012, 04:07 AM

What exactly is done to the heads?

**Spikito** · 05-24-2012, 10:26 AM

those numbers look a little high to me...id expect you to be in the 425 range...at the wheels.

that cam should clear flat top pistons ok, you could go bigger though.

**MM2364** · 09-08-2012, 02:33 PM

Thanks for the info. Sorry it's been awhile since I signed on here.

As for the question about the pistons, the receipts say they used Mahle pistons I think they have the valve resessed grooves in the top, flat otherwise. I was told the motor has 10.9 compression right now. I do not know how thich the head gaskets were they used. LS1 block with LS6 heads and intake- possibly patriot heads not sure.

I was hoping for 500 HP but it most likely won't make it the way it is now. I'm not making a drag car it's more of a autocross car that can get in and out of turns but still get up and move, but most of all I want it to start when I need it. The car is lite and the frame came with 13" rotors in front and 12 in rear- I know it will go and stop way better than it did can't wait to drive it.

Thanks for you replys - someday if the HP is too low I will either use a turbo or blower maybe we'll see.. still trying to put it together.

**MM2364** · 09-08-2012, 02:41 PM

Originally Posted by 0rion

it sounds to me like what you want is clashing with your goals. 500 to the wheels on a stock cubed LS1 will take a lot. Also, with your current set up I'd have to see 450 at the wheels to believe it. That seems pretty generous to me for those heads and that cam. The set up you have now should run pretty strong and be a good driver....I would probably wait and see what you have there before doing anything unless you're wanting to do it all out of car before putting the motor in. 500 to the wheels and you'll definitely need new/better heads and a large cam.....very large.

Orion
I was mulling the idea of upgrading before the motor goes in the car. The motor and transmission are on the frame now waiting to put the body on.

What part if Ohio are you from - me raised in Clermont County just east of Cincinnati. Thanks for the reply

**0rion** · 09-08-2012, 09:51 PM

I'm in Lancaster.....about 45 minutes southeast of Columbus. Firebirdjones is originally from your neck of the woods....he lives in AZ now but was originally just east of Cinci I believe.
From the sounds of it you'll want a cam that will build torque low in the rpm and carry it instead of one that builds it higher up in the rpm's. I don't autox but that would seem to me the best for that type of racing. I run a 228R in mine and it's a good street cam. Never dyno'd the car though so I can't tell you what kind of power I make but I would put it 400-420 to the wheels going by timeslips and trap speed.

**Spikito** · 09-09-2012, 05:12 PM

Orion...I thought you were from Oklahoma?

**Firebirdjones** · 09-10-2012, 07:04 AM

Cool swap. Orion has a good memory, I'm originally from Clermont County born and raised, then later moved further East to Brown County, and within the last few years I've been in AZ.

That's a small cam but I'd go with it as is and see how it performs. Cam swaps aren't bad when in the car, (you don't even have to pull the intake on these LS engines) and that little chevy II (we called them dueces) is a very light weight package. I'm betting it will scoot just fine and you'll be inclinded to leave it alone.

**prokilllsx** · 09-15-2012, 06:11 PM

Wow its just about an Ohio thread. I'm in Brown county.
OP, it isn't clear whether you are talking about hp at the crank or at the wheels. If you want 500 at the crank you are probably about there if not already. If you want 500 at the wheels then you are going to be spending quite a bit of dough. My current setup is around 11.2 compression, LS6 intake, PRC 5.3 stage 2.5 heads and a torquer v2 cam (232/234 duration and 598/598 lift on a 114 lsa +3). Being an automatic with a 3,600 stall I'm putting 425hp and 382 torque to the tire. With the extra slippage with the converter that figures out to around 530 hp at the crank.
Those who put 500 to the tire usually have a donkey dick cam, the best of heads, a fast 102 intake and every other bolt on available. Even then they probably wouldn't make it with an automatic. I did say probably for those about to call me out. I'm sure it's happened.
Either way, given what you say you want out of the car, the power level you are currently at is going to be a screamer. Mine on it's second time out turned an 11.82 at 115 mph, spinning out of the hole, in bad air, with a bad rear end and with the shift points lower than they should have been by at least 200 rpm. With all that and the 3.90 gear that's currently going in I'm expecting low 11's next time at the track.
Throw some good tires on it and go. Just remember to get your suspension right for the mixed driving you plan on doing so it will both hook up and turn.
Good luck. Sounds like a good start on a good project.