Mr Big

iTrader: (34)

Hi i'm new to this forum and joined because after a few google searches it seems there's a wealth of information from you guys here.
I'm looking to start a new engine build for my 68 camaro as I have recently sold the big block and looking to go for something different with a LS motor.

My question is are there many differences in building a strong short block on a LS engine with a old school blower and carbs over injected and turbocharged? Will the roots blower (8/71 weiand) be harder on the crankshaft, rods? And will I have to be more conservative with the power figures i'm chasing because the tune may not be as good with carbs over efi?

Also I'm looking at around 800hp out of the engine for now, but i'd like to build the short block strong enough to handle 1300-1500hp at a later date. What would the best block crank and rod combo be for this number? Would I have to go LSX block or would a LQ9 and stud girdle hold together upto about 1300hp?

Thanks
Adrian

novaflash2002

iTrader: (51)

Well. I can tell you there are better options for blowers. Ive done maggie 122s and recently the eforce blower. But if i were to do it again id say a whipple would be my choice. Thats it i were looking to do a blower. But im die by the turbo now. The power is awesome and has a cool name factor too lol.

Mr Big

iTrader: (34)

Yeah its not the best choice to make power with but I already have one sitting here and you can't beat the looks of the old school blowers.

Here's a video of a good example, shame I can't find out more engine info on this car.

98Z28CobraKiller

iTrader: (17)

Blowers cost HP. So you gotta calculate in how much power it takes to drive the blower. If I'm not mistaken, those old school blowers are horribly inefficient. So you need 1100-1300hp worth of shortblock to support 800. Also, at that power level, you aren't going to want pump gas and we all know how efficient a couple of carbs on top of a blower can be.

For 1100-1200, an Eagle or Callies forged bottom end will do it. Stay away from strokers. 1200+, I'd be looking at some bigger dollar stuff.

Last but not least, fuel injected turbo with a 4L80 will make you love that car like you never loved it before.

Mr Big

iTrader: (34)

Thanks, 800hp will be more than enough for now on the streets with the blower. When I get sick of it though I will look at either a pro charger or turbo setup and try and run around the 1200hp mark. I'd like to play it safe and build the bottom end for around the 1300-1500 mark for now though.

I was thinking the dragonslayer crankshaft should be ok and i'm still stuck on rods? Maybe howards billets? Or Callies ultra I beams? But first what block is good for over 1200hp? Is it just the LSX? Or can I get away with the LQ9?

87silverbullet

iTrader: (11)

If you are looking for that number, you will need a 6 bolt block no matter what IMO. So that means you will need and LSX block or if you want to stay aluminum RHS, Warhawk, or Dart block but those blocks cost $$$$$. You can go the middle of the road and get a block from ERL with the 6 bolt option. You get the best of both worlds, less weight and still have good strength.

98Z28CobraKiller

iTrader: (17)

I agree. I think 1200+rwhp is the threshold for needing the aftermarket block.

Mr Big

iTrader: (34)

I'm sure i've read here somewhere about aluminum LS2's going upto 1000hp no problems, how much stonger then is the LQ9?

98Z28CobraKiller

iTrader: (17)

200 hp

Is a rule of thumb. Lots of variables. 1200hp @ 6500rpm is easier on **** than 1200 hp 8000rpm.

Mr Big

iTrader: (34)

Thanks mate, 1200 rwhp or crank hp? Really trying to stay with the LQ9 as here in Australia the lsx block is 3 times the price.

kpeterson

Your lower number is fine for streetable Roots but for the higher number I’d go turbo. I hear you about the classic look of ’68 Camaro with an 8-71 blower. I put this one together last year. It’ only a small block with a 6-71 but it’s a lot of fun. Your 8-71 on a nicely built big block would peg the nostalgia meter and you could get the 800 flywheel hp you’re looking for. The big BUT is the fact that these old style superchargers give up so much to a modern positive displacement blower with an integral after cooler. If you want to get above the 800 mark I’d say ditch the Roots and go with any of the modern ways to get boost. Just build it once with your ultimate goal in mind. I would not bother to adapt a Roots to an LS engine. I hope I don’t get flamed for this but at 1500Hp I’d seroiusly consider a turbo tall deck big block in the 500 plus cubic inch range.