2005 Silverado

iTrader: (19)

Stock 6.0 short block. How much can be milled off and be safe?

Dustin

1FastBrick

iTrader: (17)

Are you sure about that head casting??? Sounds like it would Probally be the early Iron 873 Head castings that your refering to. Not sure you can go past around .040 off on any LS1 casting...

2005 Silverado

iTrader: (19)

100% They are Gen IV heads off of the ly6 i bought.



Dustin

1FastBrick

iTrader: (17)

Ok I stand corrected then. I dont have any info on the new Heads yet But I would imagine that you would not be able to go much past .040 and be on the safe side. Maybe some one else knows for sure...

ChevyTruck

iTrader: (39)

PM Richard @ WCCH he would have the answer for you.

1FastBrick

iTrader: (17)

I found some stock flow Numbers for the 823 heads...

Valve Lift -----.100 --.200 --.300 --.400 --.500 --.600 --.650 --.700
Stock Intake --68.8 -134.1 -200.7 -258.4 -294.2 -315.2 -317.1 -316.1
Stock Exhaust -55.6 -116.5 -163.9 -196.1 -213.5 -222.6 -257.7 -227.6

http://www.directmotion.com/dmmotors...products_id=12

2005 Silverado

iTrader: (19)

They seem to flow quite nicely at .600

Dustin

SynergyV8

iTrader: (1)

Intake and exhaust runner size? Intake/exhaust valve size? Combustion chamber volume? Any specs on those?

1FastBrick

iTrader: (17)

Sorry the site i found them on only had stock flow numbers Vs. there cnc ported numbers... and then the specs after they millied, cnc ported them and installed different Valves... I am trying to find out for sure.

Edit: found it on the other side by Richard @ WCCH - https://ls1tech.com/forums/generatio...-l92-info.html

2.160" intake valve
1.590" exhaust valve

Richard

1FastBrick

iTrader: (17)

Richard a WCCH has some info over on the tech side but again not valve size or CC measurements... https://ls1tech.com/forums/6756797-post1.html

Stock head with OEM valves:
Lift____.100”_.150”__.200”_.250”_.300”_.350”_.400” _.450”_.500”_.550”_.600”_.650”
Port 1_ 76.3_113.1_155.7_191.1_225.5_252.5_276.3_296.1_312 .0_322.4_311.9_310.3

I am also Not sure what size bore he tested them on either....

another Edit:

In another thread I found he tested a set of 5364 for some one on the board...

The test head has casting number 5364. Here’s the tale of the tape……..

4.030” test bore
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Int. 74.9 109.4 154.4 193.5 225.3 252.8 274.6 292.7 308.8 321.0 328.7 326.6 310.0 316.6
#1 Exh. 63.6 97.9 126.1 148.7 162.3 178.6 189.6 197.6 205.5 210.7 214.6 217.8 221.2 223.5
The intake was tested with a radius plate and the exhaust was tested with a 2 ½” stub pipe.

4.155” test bore
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Int. 73.8 108.7 153.2 192.6 225.2 253.6 277.0 296.7 313.0 326.0 335.8 326.9 327.3 317.1
#1 Exh.61.1 97.9 125.7 148.1 162.0 179.5 191.8 200.1 205.9 213.3 218.4 220.9 221.9 223.2
The intake was tested with a radius plate and the exhaust was tested with a 2 ½” stub pipe.

Exhaust port tested without pipe (4.155” bore).
Lift ___.100 _.150_.200_.250_.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650_.700_.750
#1 Exh.63.1 94.7 121.1 140.6 156.9 165.8 176.1 182.8 187.9 191.4 193.7 195.6 197.6 199.5

Valve dimensions:
Intake = 2.160” X 4.870” X .314”(8mm)
Exhaust = 1.590” X 4.920” X .314”(8mm)

Seat/throat diameters:
Intake = 1.870”
Exhaust = 1.355”

Volumes:
Intake runner = 260.6cc
Exhaust runner = 90.0cc
Chamber = 69.8cc