Sneakin Deacon

deciding on what i want to do with my bottom end but i need some help.

i was thinking along the lines of stock displacement, stock crank, forged rods, and blower pistons with a ~9.8:1 CR....also thought about a 355 with same setup.

any suggestions on what type of pistons and rods i should go with? and i have 150k on the stock crank, so thats probably a no go, but what all would you recommend crank wise? im only expecting maybe 400-425rwhp so i dont know if i need a forged crank just yet. all opinions are welcome...prices would be good aswell. TIA

IDOXLR8

I would first do a search. There is alot of info out there that can help you. How much boost are you planning on running? Also what kind of budget are you working with? I would also recommend going with 9.1:1 compression.

Sneakin Deacon

ive tried to do some research, but sometimes id trust someone with experience over what i read on some site.

i know to keep away from kieth black pistons, and i see alot of mixed thoughts on the power capabilities of the stock crank. im only going to be running about 8psi on an S-Trim, as i said, im only lookin for maybe 400 or so to the wheels to keep it somewhat reliable and just do suspension from there on out as i believe it would be well into the 11's with 400 horse.

the budget i am working with is about 1400 dollars, but possibly more depending on an upcoming interview. i know its somewhat a low budget, but if need be ill take the downtime to do things correctly, and have it built right. as far as compression ratio...i wanted something around 9.8:1 static (for 56CC heads) that way i could lower the compression with the heads if need be.

1BadAzzGT

Awesome advice on the 9:1 CR -- more blower friendly.

rskrause

You need pistons that are specifically designed for forced induction use. Givenyour budget, I'd suggest you look at me reasonably priced "blower" pistons too, last time I checked. The Eagle H-beam is a nice moderate price rod, though it is made in China. But for what you have in mind, stock rods may be adequate.

Rich Krause

TimbrSS

Since you will be buying new pistons anyway, I'd go lower compression with the pistons (9:1). Lowering the compression via the heads will just cost you 3x as much, as you'll have to go AFR's (or trick flows) to get much bigger cumbustion chambers.

Since you have an S-trim, it's very likely you'll want more boost/power later on. You might as well save yourself the trouble/cost/time of doing another rebuild. 9:1 will give you some leeway to do this (and still run pump gas). Say someday you get bored with 425rwhp at 8psi... think how nice it will be to just swap out pullies on the SC, retune on the dyno, and have 500rwhp at 12psi. Sounds a lot better than swapping out heads, right? I doubt you could tell much difference driving around between 9.8 or 9:1.

I would rather overbuild a bottom end the first time than to have to do it twice and spend 3x the money.

At the very least, I'd build it like this one from Combination Motorsports

2 bolt main caps with ARP main studs
Stress relieved stock LT1 crank, thoroughly inspected for strength
Eagle 4340 forged H-Beam connecting rods
SRP forged flat top pistons (dished available for low compression applications)
JE Plasma Moly ring set
Clevite 77 race bearings
Fully balanced and blueprinted
Fully assembled short block

If i didn't need a new motor right away, I'd save up for a better crank.

Sneakin Deacon

alright thanks guys...in regards to the rods...i have heard rumors that the 93's have forged rods?! i havent really found a conclusive answer on this...i know 93's got hardened pushrods.

also got in touch with cmotorsports, the block is 4k, which is pretty good, they dont use the LT1 crank anymore, they use a Scat steel crank. they also helped me out with my oil situation...i couldnt be any more happier about that!