Quik

iTrader: (7)

what is the given rule for how much CC drop you get for every .010 off a head?

tarinitup

iTrader: (11)

1cc per .006 milled

or

1.667 cc for every .010 mill

Quik

iTrader: (7)

thats what i just found out so .030 off

1.66 x .030 = 4.98 so roughly 5cc off a 69.8cc head = 64.8cc

then .020 more off since stock head gasket is .06
1.66 x .02 = 3.32 so 64.8cc - 3.32 = 61.48cc

is that math right??????

Quik

iTrader: (7)

if thats right then my 408 setup

they say with a 67cc head and my -13cc dish my SCR will be at 10.6...i assume they use a .06 gasket



and if my CC is checking in at 61.48 cc that makes total sense why the motor is pretty resistant turning over by hand even with just one head on the motor

i turned ove my old 11.1 6.0 and it wasnt this resistant.... on Tech they saying im only at 10.85 which cant be right

this 408 has plenty of resistance turning over by hand....i even had someone else back up the same comparison


does all sound correct? if it is then where is my SCR sitting at


i know for a drop from 72cc to 64.5 cc it raises the SCR 1 full point thats a difference of 7.5

my difference is 5.5 so from 10.6 and that much increase should put me close to 11.4 scr

anyone dissagree on these math numbers?

Quik

iTrader: (7)

Engine Assembly Engine Kit For LS1 Includes 4 in. Pro Series Crank. 6.125 in. Pro Billet Connecting Rods. 4.030 Bore –13 cc Rev. Dome Pistons With Rings. King Main And Rod Bearings.
Engine Assembly Engine Kit For LS1 Includes 4 in. Pro Series Crank. 6.125 in. Pro Billet Connecting Rods. 4.030 Bore –13 cc Rev. Dome Pistons With Rings.


Installation Notes
Must Use Chamfered Bearings! Kit Can Must Be Used With 6.0L Truck Block Or C5–R Block. Lunati Recommends To Always Stretch Rod Bolts Using ARP Lube. Note: All Calculated Specs Were Figured Using A .008" Out of Deck, 9.240" Block Height, And 67cc Cylinder Heads. (Stretch Gauge P/N 98401)


Features
4340 Forged Steel Crank
All Rod Pins Drilled To Reduce Rotating Mass
Gun Drilled Mains
4340E Billet Rods
10.6:1 Forged Pistons
Plasma Moly File Fit Rings
Great For Hot Street And Strip
Assemblies Come Balanced And Ready For Installation
Limited Warranty

tdrumm

iTrader: (18)

Using a 4.03" bore, 4.0" stroke, 4.03 X .040 gaskets, 13cc dish, your 67cc heads, and assuming the pistons come .008 out of the block, I get 10.65:1 SCR

I think the mistake you made above was subtracting the gasket volume from the chamber volume.

Quik

iTrader: (7)

but isnt 1.667 off the CC for every .010 off if so then that would be roughtly 5cc off the head which would take the 69.8 cc head down to 64.8 correct?


also when they do the math for head gaskets....why not use the stock spec gaskte of .060??????

i choose the .040 gasket to help aid in dropping the CR since they say you cant take much off the L92s

if i had excell i would do the math myself but i dont

tdrumm

iTrader: (18)

Oops, missed the 64.8cc heads. By my calculator your at 10.9:1

I think that stock gaskets are .054

Quik

iTrader: (7)

i see, but i thought stock was .060 but could be wrong

i knew i was closer to 11.0