Silver Rocket

Im looking to take the bare ls3 block I have and put some nice forged internals in there to make a nice n/a motor. Only problem is I do not know much about forged internals, so if someone could point me in the right direction that would be great.

The motor is going to have a set of ls3 heads and a ls3 intake. Down the road I will port the heads and intake but for now they will work. I want a decent size cam in there to make some really nice power down low with some good top end, but not crazy I still want to drive on the street. I would like to see 500-550 hp with the stock heads and intake.

Now what kind of pistons and rods should I go with?

Cold Zero

iTrader: (1)

You can have balanced forged rotating assembly from TSP
http://texas-speed.com/p-1019-tsp-42...-assembly.aspx
I prefer Callies Compstar crankshaft & rods Wiseco pistons .. quality and the cost is really in the range

now when it comes to the heads; and you would like to drive it in the street & looking for some low end HP/TQ and power under the curve .. so cathedral intake port heads is your choice .. TFS 235, PRC 237, AFR 230 .. will give you what you want down low and big power up top

Many people here may agree and disagree about the cathedral heads but all of them will agree that there is a difference in part throttle response and drivability which this cannot be measured on dyno

Silver Rocket

What is the advantage to going with the cali compstar over another? Same for pistons. Are off the shelf going to be ok or should I get customers ones.

The heads I am not worried about for now I will be using stock ls3 heads and intake. But I will keep that in mind.

Were is a good place to have this built at?

Silver Rocket

What is the difference in stroke? 4.1 or 4.125?

IDRIVEAG8GT

Well to figure displacement, the formula is bore x bore x stroke x number of cyl's x .7854

So 4.065 x 4.065 x 4.1 x 8 x .7854= 425.68"

And 4.065 x 4.065 x 4.125 x 8 x .7854= 428.27"

Either way, I personally wouldn't stroke one that far due to piston rock at BDC.

Make yourself a 415 with a 4 inch stroke.

Callies is just about as good as it gets, and Wiseco's are great for the money.

Diamond Pistons aren't bad either. Get hold of Erik at HKE. He's a badass ****, has great prices, and is one of the finest engine builders out there.

allblowdup

Going 4" or 4.1 or 4.125 is a bit of a can of worms on here. In the past I would agree that 4" was the best option due to piston rocking issues. Recently some of the piston manufacturers have 4.1,4.125 specific pistons that eliminate the issues related to the long stroke in the stock block. I have talked to a piston engineer at Wiseco about this and had it reassued that piston rock is not an issue for most applications. However when you see how far it comes out of the hole it still does make you wonder. I am running a 4.070x4.125 in a stock ls3 block with no issues but I would not expect it be a 100,000 mile motor either. If I was doing it again I would probably go a little less stroke just because or get the block sleeved.

bnvus

Agreed. My engine builder had the same recommendation. I wound up going with the Callies dragonslayer crank and Wiseco pistons in my 416 LS3 Goat. The motor makes over 500 to the rear wheels with the stock heads and intake (they have a light port job).

Silver Rocket

What if I wanted to do a small shot of nos? Say 150 at most.

Can I get away with that in a 427 or would a 416 be the better plan?

What kind of hp differences will I see between a 416 and a 427?

IDRIVEAG8GT

My 415 is laying down over 1,000 to the wheels right now with a great deal of boost. There's no reason why you can't run Nitrous.

Silver Rocket

You also have a 415 not a 427, its kinda pushing it and I didn't know if that would be safe

Unertl42

iTrader: (63)

Not trying to hyjack, but I thought measureing displacement was simply
PIE ((3.14)(r^2)) * (stroke) * (# of cylinders)

Unertl42

iTrader: (63)

r is the radius of the bore, or bore divided by 2 for those confused.

I'm not trying to be a dick, just clarifing