LQ4 Stroker
LQ4 Stroker I'm contemplating stroking to 408 my 6.0L LQ4, and just looking for some general advice. It's mainly a street car, with some autocross thrown in.
Current engine specs as follows:
I've calculated static CR at 10.46:1, which would jump to just under 11.5:1 if I were to keep everything and increase stroke to 4.000". Increasing gasket thickness to .060" drops that to 11.26:1, which a little better. Access to 93 octane is few and far between where I'm at, so I want to keep CR in check a bit.
Current engine specs as follows:
- LS3 top end (42 lb injectors)
- As-cast L92 heads milled to 66 cc's
- 4.030" bore
- Stock crankshaft (3.622" stroke)
- Mahle LS3 pistons, 4 cc valve reliefs 1.314" compression height
- Pistons .005" above deck at TDC
- Scat Pro series 6.125" I-beam rods
- LG G6X3 cam (23x/24x @ .050”, 64x/.61x, 111 LSA)
- Comp 921 springs
- Stock rockers
- 7.400" Comp pushrods
- GM 4.080" x .051" head gaskets
- 1 7/8" american racing long tubes with 3" Pypes exhaust
I've calculated static CR at 10.46:1, which would jump to just under 11.5:1 if I were to keep everything and increase stroke to 4.000". Increasing gasket thickness to .060" drops that to 11.26:1, which a little better. Access to 93 octane is few and far between where I'm at, so I want to keep CR in check a bit.
Last edited by hookemdevils22; Apr 10, 2018 at 09:31 PM.
Since I don't see an actual question I'll just go ahead and mention that I'm running 11.5:1 compression on 93 octane. Even on 93 i'm running reduced timing to prevent knock. Its not much bit it is a few degrees. I can't imagine running any less octane with this compression
I’m looking for comments on stroking what I currently have, specifically the CR and perhaps cam. From the sound of it, I’ll want to decrease CR a bit.
I reached out to LG with regard to the G6X3 on a stroker, we’ll see what they say.
I reached out to LG with regard to the G6X3 on a stroker, we’ll see what they say.
Increasing gasket thickness is not a great way to lower compression due to low octane. Quench needs to be around .040” so less milling of the heads is preferred
Shoot for 11.0:1. And your mid 230s IN cam will work nicely
Shoot for 11.0:1. And your mid 230s IN cam will work nicely
Forged 4.00" Crankshaft 1850 BW Hi Hookem, I can supply a 4.00" Forged Crankshaft with 1850 BW. (Scat Plant)
The CHOICE of a RaceTech piston is another item I cam supply.
What are your Rod Weights B/S ?
CORRECT engineering could save costs with respect to engine balance costs.
Your 11.5 CR will be fine as you have REDUCED the R/L, good for knock resistance.
Lance
The CHOICE of a RaceTech piston is another item I cam supply.
What are your Rod Weights B/S ?
CORRECT engineering could save costs with respect to engine balance costs.
Your 11.5 CR will be fine as you have REDUCED the R/L, good for knock resistance.
Lance
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Since you can’t reuse the pistons for the 4” stroke, have you considered a different dish volume?
Pantera, I don't have rod weights on me, but should have them in my folder at home.
ETA
It put down 414/373 through a 4L80e.
yeah, big cam and big exhausts hurt it down low. the T56 keeps it fun, but I'm exploring ways to add to what I have. another guy I know ran an LY6 with a smaller cam, 1 3/4" headers and 2 1/2" exhaust, which made 414/400 but with a nice plateau of a torque curve.
