Spectre86

iTrader: (42)

Ok basicly I picked up a bare LS2 block for a winter build. Consdering either a 402 or a forged 364.

Im basicly looking for the bore stroke differences between a 402 rotating kit and a stock 364 bottom end.

Most 402 kits range from 1700-2500 depending on options.

but a stock LS2 crank can be had cheap. then with just a forged piston/rod combo, be almost half the price.

So whats the specs on the LS2 with a 402 bottom end and a LS2 with a stock 364 bottom end.

This is what I find most when I search

4.0"-4.030" Bore 4" stroke. 6.125 rod length 402?

4.0"-4.030" Bore, 3.622" stroke 364?

whats the rod length on a 364?

also, difference in cranks?

max bore on ls2 block without resleeving?

sorry for odd questions but I was actually looking for a ls1/ls6 block and got a good deal on a ls2.

ss1

iTrader: (32)

You're pretty much right on with what you've mentioned already.

With the LS2 aluminum block keep the bore size to a minimum. There is no need to go .030" over, just have it honed .005"-.010" to clean & true up the cylinders. The guys going .030" over are usually running iron LQ9 blocks.

Your aftermarket engine kits will typically come with 6.125" rods, and the correct pistons to go with tht stroke of the crank you choose. I believe stock LS1, LS6, & LS2 rods are all 6.098".

A stock LS2 has a 3.622" stroke crank, for 364ci.
A stroked LS2 with a 4.00" stroke crank will be 402ci.

Good choice on going with the LS2 block btw.

BERRY GAY

go here http://www.cdnperf.com/ this will tell you alot.

I would go a 412 or the 415.
but go the the web site it help me out
berry

Spectre86

iTrader: (42)

cool thanks man. so when looking at pistons, I need to find one that says its designed for a 6.125 rod

so what would happened if a 3.622 crank was used with a 6.125 rod and a 4" bore piston? pretty much using a stock crank instead of a 4"

ss1

iTrader: (32)

Unless you're using stock rods, most of what you'll find will be 6.125".

A stock crank with a 6.125" rod and a 4.00" piston will still be a 364. The rod length doesn't change the displacement of the engine.

In short, here's a quick rundown of some things you'll need to figure out...

-Determine whick crank you want to use.

-Determine what length rod you're going to use.

-Decide where you want your compression ratio to be.

-Determine which cylinder heads you're going to use.

-Choose a piston based on everything listed above.

You could also get your pistons before the heads, and then have the heads milled to a desired cc so you hit your target compression ratio. It's really not difficult, just a matter of putting the correct components together.

KCS

iTrader: (20)

There is a spec for the pistons called compression height. It it the distance from the center of the wrist pin to the top of the piston crown. This is what you need to pay attention to when selecting a piston for any given stroke and rod length combo. Half the stroke + rod length + compression height = pretty close to your deck height.

For example, LSx blocks all have right around 9.240" for a deck height. If you had a 4.00" stroke, a 6.125" rod, and a 1.300"CH piston, it wouldn't work:

2" (half stroke) + 6.125" (rod length) + 1.300 (piston CH)= 9.425"

That would basically put the piston .200" out of the hole. Now say you use a stock crank:

1.811" + 6.125" + 1.300" = 9.236"

That is pretty much ideal, since it gives you plenty room to clean up the deck when it gets surfaced. Especially if you use a stock head gasket.

99blancoSS

iTrader: (115)

^^^^

I can set you up with a correct assembly. You want to clean the bore up. .005 on the block first to true it up so you looking at a 4.005 bore with a 4" stroke for a 403.

If your going to build it you might as well drop the coin on a 4" stroke crank, unless your going with a power add. Nothing worse than dropping good coin and amking stock power levels. (for me anyway)

Spectre86

iTrader: (42)

thanks for info man!

interested. No ready to purchase yet as I just bought the 90/90, long tubes and xpipe and the ls2 block. I have to head up to the portland area soon to have wong tune it. full time college and part time work, modding takes a lil longer

where are you located at in oregon? wouldnt mind meeting up to see what you have got. Im still in the research part of my build. im assuming a rotating kit runs between 1600-2500 depending on options and whatnot. seems to be the best bet rather then piecing everything together. wish i had the extra coin right now thought. those ls2 heads you sold were beautiful

99blancoSS

iTrader: (115)

Yeah sorry I couldnt hold the heads for you, had to get them out the door. I can hook you up though when its time with a killer set of heads as well and great deal on them.
I'm in ST Helens Great little town on the way to the coast/Astoria on rt30.

Are you in Corvalis or Eugene?

BTW yes your pricing is right on.

Spectre86

iTrader: (42)

+

what kits do you deal with? eagle?

no worries, based on your specs, they were worked over pretty good. someone got a nice deal.

which ones? AFRs? im partial to them just because a few years ago i got my *** handed to me by a late 80s camaro with a carbed sbc with afr heads. lol.

im just about an hour south of eugene right off I5. was in corvalis and then newport this last weekend.

do you do machine work there?

ssmith512

Go 402. There is no replacement for displacement!

BERRY GAY

I would only buy the go stuff and eagle is not the best. Comstar is one of the best. As heads go trick flow make great power but the down side is you need to do aftermarket rockers. But the AFR you can use the stock lsx rockers!!!!