partemisio

iTrader: (1)

My lq4 got some bearing knock on the dyno due to low oil pressure so it's time for a rebuild. I am looking for suggestions for what cubes to go with. I was originally going to go with a 408 but I'm wondering if I should go smaller to keep more of the cylinder wall material since I plan on going turbo in the near future. Not sure what else you would need to know other than the fact I plan on turbo. I'm not worried about heads/cam as those will be chosen later. I just want as much longevity as possible with decent street manners. The plan is to have somewhere north of 600rwhp with the turbo but nothing too crazy.

Here's what I currently have:
240sx with lq4 swap
t56
twin disk
80LB injectors
AEM stand alone
TSP cam
317 heads


Here are the things running through my head:
408 stroker kit from TSP
Smaller stroker kit from TSP (not sure what other size I would go with)
Factory cube rebuild with forged rods/pistons if I can salvage the crank
Completely factory rebuild with replacing on what's needed


If you need to know anything else let me know. Thanks in advance for any advice.

That_One_Person

iTrader: (4)

If you "only" want 600 I doubt you'd want to spend the extra coin on 4XX cubes unless you want room to grow. You could do forged rods/pistons and just bore it .030" or .005" over and have yourself a nice 370 or 365. Honestly if it's already coming apart i'd put the stronger forged parts in it. I know budget builds are cool but the added strength will give you a little peace of mind.

redtan

iTrader: (5)

Honed minimally to cleanup the bores and ensure a nice smooth wall then boost the **** out of it. You'll easily get to 600rwhp.

KCS

iTrader: (20)

Just do a 370ci build. 4.030" is not really bad at all for a power added combo; plenty of meat left.

redtan

iTrader: (5)

Definitely, but would 5ci of displacement make that much of a difference in a boosted setup running somewhere in the 10-12 psi range?

My thinking is by doing a minimal hone you can save the meat of the block for further rebuilds if necessary while still staying within a range of good wall thickness and a plethora of available parts.

If you're at 0.030 over and you need a rebuild you're starting to run out of easily available options past that point unless you go to a custom piston or jump up to LS3 size bores which is starting to push the limits of the block as not all of them can go that much over.

A.R. Shale Targa

iTrader: (2)

Just to add to this thought......
The op could just 2 step hone .005" and have decent ring seal for an N/A application, however there is a science to boring say the first .025" with a cutter, then three step honing the remaining .005" out with a final few licks of the flapper wheel on a drill. He did mention boost right ????
Microscopically speaking the cutter forms the base to create what's referred to as the plateau hone finish. When combined with a quality set of Speed Pro Hell Fire rings and Total Seal Quick Seat will help the slug slammin' fury stay on the north side !!!!

partemisio

iTrader: (1)

Thanks for all the suggestions. Sounds like I should go stock displacement if possible. Stock rods and pistons are good for my goal I'm assuming? Are arp main/rod bolts necessary?

Thanks again.