I am in the budgeting stage for a kit car build i am seriously considering and as far as the engine i am planning on roughly 600-650 HP at the flywheel, n/a on 93 octane gas. I want the engine to have roughly 8 - 8.5:1 compression so i can possibly add a supercharger later on if i feel the urge to. With that said i would like to stick to an iron block and forged internals to make it reliable as possible.
Basically i have decided to use a LSX block (427 cu inch) for its strength and 6 bolt heads and plenty of cubes. What kind of heads, cam, pistons, and other essential parts would be necessary to reach the goals mentioned above??

Also $$ is not a big concern(but i would like to stay under 18K) and i plan this to be mostly a street car but will see the occasional track.

 

You probably won't be able to make power like that with that SCR. For 18K you could build a boosted and forged motor making even more power.

 

unfortunately i am not sure if i can fit a SC so my goal is to build a N/A engine with somewhat lower compression but in the 600 hp range so that if i cannot fit a SC i am still not disappointed with 600 hp. Also if i went with a high compression engine and then found out i could have fit a SC, then i would be because i would have to rebuild then engine or use 110 octane(which i dont want to do and i am trying to avoid).

So what kind of of set up could i run that would allow me to have approx 600hp but still have the possibility of boosting in the future while having a reliable set up?

 

You are gonna have a really hard time making that power, with that compression, and at that displacement.

You could go up a bit to 10:1 and make decent power. Then if you ever get a supercharger, use a methanol/water injection system to control detonation. Depending on how much boost you plan on making, and what supercharger you use, you may not need it at all.

 

i wouldnt run to much boost 5lbs maybe 10lbs of boost at most. I dont plan on going crazy. How easily can a LS2 or LS3 be modified to achieve 600 hp N/A but keep the compression at about 10:1?

 

I'm not 100% sure. I've seen a lot of L92 headded 408's make around 550hp to the tires, but they usually have slightly higher compression. If you were to run an LSX block you could go larger than 427ci and still have meat left for rebuilds just in case, and make that 600hp mark that much easier. Couple that with some of the really nice 6-bolt heads out there, like all pro or ETP, and I don't see any problems in making 600.

 

Interesting challenge, your looking at some type of solid roller setup up and it wont be cheap. 600 n/a rwhp with a 408 can be done but it has to be the right combination. A 416 would stand a chance I think but again at that low compression your talking about a well matched setup costing a chunk of coin and being a solid roller most likely.

 

l92 block 414ci with afr225 heads will make some excellent power
perhaps 600bhp with aggressive cam, intake headers and calibration

 

I found two engines at http://www.mastmotorsports.com/ called the LS3 427 SS or the LSX 454 HO....

They dont meet the compression requirement but i wouldnt supercharge either as they make plenty of HP and TQ for my application. and 11:1 is perfectly fine for 93 octane. The builds look pretty strong and come with an ECM.

The only question i have is does anyone know what kind of reputation this company has??? do they make good motors?

 

How much power are you wanting to make and what is the budget? You can make a lot more than 600 flywheel if you have the right parts. Over 700 flywheel is doable with a big cube ls7 motor, just have to have the coin.

 

Well, since you're ok now with using 11:1 compression, and no sc'er, a 500 RWHP (~625 FWHP) engine is a piece of cake to build, many different displacements from 408ci-454ci and in many different combinations of bottom end and top end parts.

Just do a cheap 416ci, there's builders all over the place making 530 RWHP and very streetable with 230 sized cams. Thats about 660 FWHP through an A4 (20% DR loss).

You shouldn't use any builders that don't offer at least 12 month/12,000 mile warranty if no power adders are used and THEY tune it. Thats my opinion.

 

Now that may be what I am looking for.

Not necessarily low compression or run on 93, but appropriate compression run 100 octane is just fine, dry sump system.

Not a street or strip engine, but a road race engine, hopefully make one season before rebuild. 16-18 forty min races, plus warm up and qualifing

 

I don't know about their engines, but they seem to be the onyl ones trying to exploit GM's form of variable valve timing. At least they are thinking outside the box.