tirefryin_s10

iTrader: (3)

I am looking for a little input from some of the experienced ls engine builders.

I currently run a stock bottom end 6.0 with twin 70mm turbos and on 14 psi with pump gas it makes somewhere just shy of 800 rwhp and runs 147mph in a 3250 weight fox body but looking to step things up a bit.

I will likely continue running the stock motor to see how far I can go with it while working on this new one.

Here are my thoughts:

Iron 5.3 block (Have all cleaned and mag'd already)
Stock 3.662 stroke crank(possiblybuy a 4" stroke )
Stock main caps pinned and studded
Wiseco 3.800 bore forged pistons
H beam rods
Custom grind comp 242/238 .610/.605 on a 115+3(Have already)
Ported 317 heads(Have already)
yella terra ultralite rocker arms
undecided on which intake manifold yet currently running LS6 with ported 78mm TB.

What I am thinking is this combo only works out to 328 c.i.d so I will be loosing 36 cubic inches but I also plan to spin this one a lot higher so I am hoping spool time etc will not be a big concern.

I am thinking the small bore gives more meat for better head gasket sealing surface and also leaves a LOT of block strength there. Run 20+ lbs and spin to 8k or so.

What do you guys think? This combo work? Looking to do something a little differnt then the standard 370/408 combo.

Thanks

Neil

gnx7

iTrader: (28)

Larger bore so you can run a more common sized piston. I don't think you have anything to worry about with bore integrity since it is iron already. I would get some thick deck cylinder heads to make sure the head gaskets stay sealed if you are going for 1000rwhp+.

tirefryin_s10

iTrader: (3)

I do not like the 5.3 blocks bored to 3.905 and if I want to go bigger I will either need to retire this 6.0 or get another one. I just thought this would be a neat way to build something out of the box.

The pistons are a shelf stock piston from wiseco so they would be no differnt then running a 4.030 bore shelf piston.

I will not be buying heads as the ones I have work great especially right now.

slow67

iTrader: (2)

A stoked 5.3 (4.00") and +.020 would give you 363 cubes.....

tirefryin_s10

iTrader: (3)

I have also considered going this route .... I think it would offer a lot more block rigitity then a standard 6l would and cubes would be the same.

extremetoy

iTrader: (17)

very interested in this as well...but have nothing to add

r.barn

I really dont think you gain that much block rigidity by not boring out a 5.3 iron block
to the LS1's 3.989 bore. The iron itself makes an already strong block design that much stronger.

I would think you would break rods and cranks before you split a factory Gen-III iron block

How do those twin T-70's spool up on your combo ???

They plot out like poop when you run the math on the compressor maps.
Way past the surge line on spool up. Do they act or sound weird on spool up ?

tirefryin_s10

iTrader: (3)

Don't always believe the map LOL .... They work/sound perfect.

http://www.youtube.com/watch?v=gTEWw...eature=channel

The Beast

iTrader: (16)

I guess I'm kinda confused as to why you think a bored 5.3L block is more rigid/has "more meat" compared to a bored 6.0L block. You know they're not the same block, correct? Also, with 317's on a 5.3, I'd think that valve shrouding from the smaller bore would hurt the flow of your heads.