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How are you at 11:1 compression? Is that calculated SCR with the cam or just a piston/combustion chamber calculation?

 

IIRC, dish in LQ4 pistons are ~6.7cc can anyone confirm please.

 

10.8:1 scr with dished lq4 .060 over pistons and 4cc valve relives
milled 243 heads .030.
4.085 bore .051 compressed gasket
+.015 deck
stock crank,rods, .060 over 8cc dish piston
if i would not have machined in the vr's it would be right at 11:1 even with dished pistons and the milled 243 and .051 gasket.
the piston protrudes .015 out of the bore.
SD tune
mostly weekend and gtg car. i dont dd as much anymore, but i use dd it for about a yr after i built engine. engine has around 40k miles now.
avg. about 23mpg with t56 full weight and 18in wheels

pistons used are Speed Pro part number:
H857CP (8) 99-02 VORTEC 364CI (6.0) 250.00$
1.5/1.5/3.0MM Sealed Power Rings (4.00-4.06) bore 100$
coated skirts, press fit stock rods.

 

does anyone else have any good rods and piston brands to reccomend?

 

i got coated wiseco pistons and compstar rods in my turbo motor, and no problems yet

 

So 11:1 compression on a stock LQ4 would be 59cc chamber heads with a .041 gasket, correct?

 

a stock lq4 is around +.010 deck, a .041 gasket would net .031 quench.
perhaps a bit on the tight side. i try to keep it around .035-.040
u will have to verify ptv for sure with that gasket. even though the spherical dish does allow for some valve clearance,

with a .041 compressed gasket (assuming the bore is around 4.08) and 59cc chamber heads, SCR will be at around 11.31:1 with a lq4

 

and the GM 6.0 MLS gasket is how thick?

 

ls3 is around 4.085 .051 compressed

 

lq4 head gaskets are 4.045 bore compressed .051 compressed thickness

 

i measured them at same bore, but iirc the compressed thickness was .055

 

We also have a 227 runner with a small chamber in the new PRC castings! It's available with small chambers for kicking the compression up!

 

any more info?
chamber bore? cc? valves? flow?

 

great info.
bookmarking for future project.
Thanks,
kory