Okay I believe its time to build a new motor guys! Im quite happy with where my car is for right now im sitting right where im not going to hopefully break anything but its fast to. But now im wanting to build a motor from the block up. I have been thinking and going back and forth on what motor to build. LS7 is by far out of reach for me, to much money for that. But would you guys do a ls1,ls2,or an ls6. Im leaning more towards a ls1 with forged internals a good set of heads, bolts, etc. With an ls6 intake, a mild cam and a big shot of nitrous. Now what would you guys think also keep in mind I am taking machine shop classes and cnc machines arent a problem. But what kind of tips and comments do you guys have for me. Its gong to take me awhile and I realize that. thanks

 

Depends on your goals, wants and how much $$$$ you want to spend.

Personally if I build a motor from the block up I'd go 402ci LS2 based for the aluminium block. Weight and CENTRE of GRAVITY are important to me. For a drag only car a cast iron 408ci would be fine, but I like cornering

Forged internals (low CR ~9.1:1) some decent heads (probably ported LS6 units) and a sensible cam, plus a single turbo setup. 650-700rwhp all day long and on 93 octane.

Either that or go high CR setup on the same block with an OTT cam and run n/a with a 200 shot on stand by.

 

that sounds like some good advice.the ls2 402 combos are very affordable and can put down some sweet numbers.

 

I'd build a 402 or 408

 

LQ9 based 408 with 8.5:1 compression, fully forged internals, ported 6.0L heads, mild cam, proper fuel setup and a GMR twin turbo setup with a A2W intercooler. You'd be sitting pretty happy at 700+hp/700+tq. Yes, it is costly, but you could always build the motor and drive it for it's break in period while saving for the turbo kit. If you are going to build a motor, build one you won't ever need to upgrade!

 

Driving a motor running only 8.5:1 SCR without a power adder would be a PIG plus terrible fuel efficency.

Just look back to the mid 70's where the Poncho 400ci (6.6 litre) struggled to make 185bhp and 10mpg, largly due to the CR. As only a few years early the RAM IV engine (same 400ci but with better heads, i.e. higher CR) was making ~370bhp SAE Gross.

 

I'd look into building an L92 setup. Block's got a 4.060 bore right off the bat, so that along with a 4 inch crank gets you a healthy 412 CI, and I do believe that the block will be about the same price as the ls2 block, around 1200 when its all said and done.

Now, the internals and top end are gonna depend on what you want to do with it. I see you're already running nitrous, if that's the route you plan to stay on, I'd try to get the compression to around 11.5 to 1, and get a good nitrous piston for it and good rods, so you can hit it with more juice then you are now. ET 240c heads would be something I'd look into if you want to reuse your stock rockers and/or already have a fast intake or want to run that intake, or if you're willing to wait a while, look into the L92 heads, there's bound to be an intake that will work for that soon, and those heads with some mild intake and good exhaust port work will make HUGe power #'s.. but this will require all new valvetrain, rather then just pushrods.


A better idea is to figure out what you want for an end result, what is the goal? Then, once that is decided, start talking to sponsors on here and see what they have to say, talk to a few differnet ones, as they all may have a diffenrent path to get you to the same goal... and then look at your budget, see what seems like it will fit what you can spend and get started! 2 things to remember, #1 don't change the goal, once you decide on what it is thatyou want, don't deviate from that, or you'll end up spending triple the amount you planned. #2, all parts must work together! Because of this, I'd reccommend allowing the sponsor or whoever you choose to do the project to take care of getting whatever is needed, this will insure you that what parts you decide to use will work together. One thign is for sure, unless you are racing in a class with a CI limit, go as big on the displacment as you can afford, the more cubes you have, the easier it is to get to whatever power goal you have in mind.

I'm not sure where you are located, but if you are planning another nitrous setup, give eastside a call, they have done alot of solid strong running nitrous setups, from bolton cars like yours to full blown 8 second race cars. They can for sure give you some solid advise to get you to whatever your goals may be, from a street pounder, to a race setup.