Kk92

so I need some help guys. Trying to plan out an engine build and I'm not sure if it is feasible. So the goal is for a reliable, well mannered, torque monster. What I would like to do is build an lq4 408 stroker bottom end and then mate it to a set of either ported 243's or untouched l92 heads and a minuscule cam. I would like something that idles like an ls6 with only a hair more lope acceptable (I frequently fire up my truck for small trips around the job site and have to meet with customers so something with a decent lope is out of the question) not looking for high horsepower numbers at all and am perfectly happy with between 420-450rwhp. That being said what I am hoping to achieve with the stroker set up instead of just running an lq4 bottom end with the 243 heads and an ls6 cam is an engine that has a very reasonable redline of 5500-6k that idles similar to stock and just has just soul wrenching amounts of torque down low. Would be mated to a 4l80 with a 2k stall and (hopefully) 4.10 rear gear in a single cab short bed 951500. So any criticism of my plan or head/cam suggestions or even if an lq4 is even the best block for this particular project, any and all advice is appreciated.

G Atsma

You would want as much compression as you can get away with, plus as much displacement as possible.
For a cam, look at the truck cams from either(or both) Texas Speed and Performance or Cam Motion. The milder ones will idle smoothly while still building up the torque a good amount.
Stay away from rectangular port heads (L92, LS3, L99, etc.) as the large ports kill off low end torque. Ported 243's or aftermarket cathedral port heads like Air Flow Research will do you a better job with low end torque, and still deliver good power up top.
A stock converter will be fine too. Higher stall speeds make the engine wind up too much.

Darth_V8r

iTrader: (4)

Just to add here....

The 408 will make torque. You can do 243 heads on the cheap if you want. I do lean to aftermarket, but depends on your budget.

A 227/235 cam will work well with about 11.5:1 compression. You'll have plenty of torque.

If you want to rev it, think more 232/240 or similar to help it breathe. Maybe even bigger, honestly. And use the L92 heads instead of 243.

Depends on your goals. Since you stated torque, use the smaller cam

Bspeck82

Your powercurve will be determined by all the parts in combination, it is more complex then just the square vs rectangle vs cathedral debate. The cam and intake manifold play a big part in what your powerband will be obviously. High lift low duration cams with an intake manifold with long narrow runners will build more mid range torque. Proper rectangles have rrspectable port velocity characterisitcs for good mid range torque especially when work is done to them by a professional.

Kk92

So what is a suggested build for my goals?

Kk92

Recently looked into the IV gen blocks for a stroker build just because I was reading he the cylinder wall go further into the block so you don't have the issue that you get with the lq4 blocks of the piston skirts coming out of the bottom of the cylinder and increasing wear

Darth_V8r

iTrader: (4)

LQ9, 4" crank, L92 heads, 227/235-113+4. 0.625/.608 on lift. Ls3 intake, long tube headers, ls3 injectors and fuel rails

Bspeck82

pretty much yup.

Kk92

So the piston skirts coming out of the cylinder at bdc isn't an issue?

Kk92

Also how should that cam act? As muh as I love a big cam in a weekend car this thing is going to be my work truck with daily interactions with customers so it needs to be pretty mellow sounding

93Polo

iTrader: (5)

If you want mellow I would take a look at running a 6.0 with a LSA blower.

Darth_V8r

iTrader: (4)

That cam would be docile in a 408. Displacement absorbs cam big time. Especially stroke absorbs displacement.

Brons2

Money no object? How about a tall block LSX? Max stroke 4.5, max bore 4.250 for 510ci. Hey one can dream right? That would be some serious, serious torque.

https://www.summitracing.com/parts/nal-19260100