DARKmj16

iTrader: (6)

so im trying to build a ls1 motor that makes 650ish rwhp na (no turbo/spray/charger) but still streetable dd. will be using fuel injection. this is gona be a budget build also, so 650 is the goal but if its 500+ ill be happy. I now ill need new parts like heads/crank/rod/pistons ect. but the question is what parts and specs do I need for the ultimate goal of 650-700rwhp.

five7kid

iTrader: (14)

Personally, I think your criteria are mutually exclusive. "Budget", "RWHP", "NA", "DD" - at least one, and maybe two, of those are going to have to go.

650 GFWHP, DD, NA - Those are achievable with about an $8k budget.

Start with a 6.2 block. A stroker kit of decent quality will run you about $2500. I'd plan on $3k. The Manley kit for my 6.0 was about $2500. Then it had to be balanced. It's all forged, 4" stroke, 6.125" rods. But don't skimp here.

Plan on ported rectangular port heads. $2500 or more there.

Gee, we're already up to $5k.

Call Bullet for a cam. About $400. Figure on new lifters and pushrods.

EFI will be more DD friendly, carb more HP friendly. Pick your poison. A FAST intake, if you go EFI, is about $1k. You can do a carb intake with injector ports, with hat and TB that will make good power and probably still fit under the hood. Carb will require cowl hood.

And you'll have to get this tuned. HP Tuners is $500. A good dyno tune will be at least that much. Even a carb should be dyno tuned.

So, are you still on board?

Atilla the Fun

A new pair of LS3 heads runs $600, and I could do a stage 1.5 port job on them for as low as $ 200 plus shipping if they don't need me to include flow bench results. There's $ 1800 saved versus a pair of Mast heads, which I say are the best. But those castings have far better short-turns to begin with, so there's no getting LS3 or LS7 heads to equal Mast's results, no matter who ports them. And if you're against boost or nitrous, then you'll need a really "big" solid roller cam, so forget EFI entirely. You'll need a Dominator on a single-plane, or better yet a dual-carb tunnel ram setup. But you'll spend more on this because of parts and ignition than you would just boosting an LM7 to 700 HP with a single T76 turbo. That option lets you have over 25 MPG, with clean emissions and daily-driveability, and a quarter-million-mile life expectancy, while your plan will never see 15 MPG, and won't last 50,000 miles.

TraviZ

iTrader: (2)

This thread is funny unless this is a budget build for a rich kid where a budget is 10k. Then maybe that will be enough to cover a motor of that horsepower estimate with streetability but still definitely not a good daily driver choice.

morbital

If your gonna spend that much money. Just go to summit. There's a 427 ls on sale for that price range and its a turnkey. 550hp and 650tq. Not only that u gotta rebuild your 10 bolt and tranny. Once you send all that tq thru your stock drivetrain, good bye rear end. And ls1 don't hold that much power because its a alum. Block. Which is why all f bodies love the lq motors. Just like the other dudes mention to you there are ways to save $$$.

Orr89RocZ

iTrader: (20)

You arent doing this on a budget. You arent doing it with an ls1. You will need a 4.125 bore block. Ls7 or aftermarket. Forget ls3 rectangular ports... Ls7 heads with a good port job. Or one of the aftermarket castings, canted valve stuff like mast. Thats gonna cost you several grand right there. Solid roller and 7500-8000 rpm will get it done.

Heres a 680whp ls7 build. Efi and street driven. Efi intake alone will be over 2500$

http://speedtalk.com/forum/viewtopic...=Ls7+Greg+good

10k$ wont even cover the top end of a build like this. This isnt cheap and 650 whp is a ton of power.

DARKmj16

iTrader: (6)

hmm. consider my *** handed to me >.>

suppose ill stick to an older sbc. seems to be cheaper and puts the power down

Orr89RocZ

iTrader: (20)

Your not doing that with a sbc on the cheap either...

Do you realize how much power 650 whp is?? To do that na is extremely well build for a pump gas motor

Only way you will do that without super expensive parts and high rpm is with a big cube big block chevy. A proper 540-555 big block will do 750-800 hp without breaking a sweat.

Atilla the Fun

False. 400 cfm is not impossible from hand-ported LS3 heads. But I won't go that far for $80/pr, which is what I typically charge for most heads. And with a healthy solid roller cam, 400 cfm will feed 800 horses from a 427, whether LSx or BBC.
Putting 400-cfm heads on a BBC is actually the more costly proposition, bu quite a large margin.
And displacement has little to do with it, except that more displacement equals a lower RPM range, and that means cheaper parts will suffice.
Could I do an 800-horse 376? Sure, but why?

Orr89RocZ

iTrader: (20)

You really think its all about what a head flows? If so you shouldnt be giving advice on this build

You build an ls3 headed motor that makes 650+ whp and you'd be the only one out there doing it.

And good luck getting a good solid roller to work on the thin ls3 rocker casting area

Z28FAST1

Yeah top it off with a nice TPI and you'll be golden

STREETDEMON

i love hp and making it happen, i wouldn't want to dd a 650+ rwhp ls/lq vehicle that didn't have a power adder or wasn't fitted with a big block.........

OP, sounds like you need to do some more research before you start pulling the trigger on question threads like this. you can make more power per dollar with the ls/lq platform, and do it more efficiently than with a sbc. granted the initial swap costs will make it more of a level playground.

what were your plans for 650hp in a dd? mine puts 400 to the ground and it's not exactly enjoyable driving it in stop and go traffic.

Pocket

iTrader: (24)

I hit that mark at 14psi. I wish you luck doing that with any n/a SBC or LSx. A bbc, sure but not any small block without a serious power adder

Orr89RocZ

iTrader: (20)

You can get there on a very serious big cube motor but as said its extremely expensive and not going to be that fun to drive normally.

A good heads cam ls7 build will get to 600whp, and some shops claim 580-600 cam only with supporting mods but its a very rough idle and low speed driving car

500-550 is much more achievable and driveable and brutally fast on the street. You can run ls3 heads here and make the numbers with a good 4.030"+ bore build. Several ls3 and bigger cube latemodels making 480-530's whp with fairly simple builds

DARKmj16

iTrader: (6)

I agree street. I would love a super charger but figured the cost of one would be more then just building the motor up. I plan on using my car as a dd ofc but on the weekends road racing. would 500hp+ a super be reasonable.

STREETDEMON

a good cam and heads will get you over 400hp in a cost effective manner and be more car than you would need on a road course. 500hp to the ground isn't cheap....unless you ebay turbo it.

"you've got to pay to play". cheap, realiable, fast.....pick 2.

DARKmj16

iTrader: (6)

obv I prefer realiable and fast. well 400hp will have to do for now then, can always build on that I suppose.

now if I get new heads and a cam to reach the 400+ will I need anything else? (other then a lower end rebuild to handle it, which ofc will be done)

STREETDEMON

cam will require new springs and pushrods. save for some headers, with the increased airflow you'll need a way to get rid of that in an effective manner. put in a new timing chain and oil pump. new ls7 lifters are cheap insurance also.

i wouldn't worry about the bottom end unless the engine is a complete shelled out rebuilder. shouldn't have to touch the bottom end on a running ls/lq platform...might check the bearings, if they are good to go, run it. unless you are wanting to spin it to the moon.

Orr89RocZ

iTrader: (20)

Do you already have an ls1 motor in hand? Ported stock heads plus medium cam is 420-450 all day long
My buds ls1 has ported 243's and a 224/230 baby cam and made 424whp thru automatic and 4" cutout

If no motor find a 6.0 and do a ls3 top end with a cam suited for those heads. Not uncommon to see 450-500 whp

DARKmj16

iTrader: (6)

I have a 5.3L on hand im using. so the bottom end will be fine for that much power? thought it would break something but ok more money for heads. headers ofc are going on. and I don't need a crazy spinning motor the stock (what is it) 6000rpm is fine.