this was posted over on LS1Tech by or sponsor Richard from WCCH.
thought you guys might enjoy the data

I recently flow tested a new pair of LS7 heads and intake manifold. I realize LS7 head flow data has been previously posted but I thought I’d add a bit more data to the mix. The heads were casting #8452. The test valves are oem. Apparently the titanium intake valves are on hiatus for a while, but I managed to scare up a couple for testing and mockup. The intake head flow is as follows:

Lift __.100 _.200 _.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650 _.700
#1 Int. 75.5 162.7 245.5 279.1 305.8 326.4 344.5 360.2 370.7 333.7 336.1
#2 Int. 75.3 163.5 244.0 277.0 303.8 323.7 342.2 359.4 370.6 332.3 335.9

The heads were tested on a SF 600 flow bench.
The intake ports were tested with a radius flow plate on a 4.155” test bore.
I then tested the same ports with an LS7 intake manifold bolted in place:

#5 Int. 74.9 157.7 228.2 254.8 276.9 293.9 306.5 317.4 325.4 331.4 302.2
#7 Int. 75.0 158.3 227.6 254.5 276.0 293.7 306.5 316.9 326.0 331.4 304.8

Due to word wrapping I trimmed a couple of lift points off below .300" and above .700".
As you can see the intake manifold extended the flow peak by .050”, though it reduced peak flow by 45cfm. The flow peak is within the designed lift curve. This is very impressive flow under the peak. Great job designing and machine finishing the ports, chambers and seats.
On the exhaust side, the exhaust ports flow is as follows:

Lift ___.100 _.200 _.300 _.350 _.400 _.450 _.500 _.550 _.600 _.650 _.700
#1 Exh. 57.5 118.8 176.7 207.3 221.7 229.7 235.9 240.8 243.9 246.2 247.9
#2 Exh. 26.2 115.4 168.5 194.4 206.2 213.4 218.5 222.9 225.6 227.8 228.9

The #1 exhaust port was tested with a 1.875” dia. Pipe 2.5” long.
The #2 exhaust port was tested with out a test pipe.

The runner volumes are as follows:
#1 intake runner = 259.0cc
#3 intake runner = 259.4cc

#1 exhaust runner volume = 86.4cc
#3 exhaust runner volume = 85.0cc

#1 combustion chamber volume = 70.0cc
#3 combustion chamber volume = 70.4cc

This should go a long way in helping explain why the LS7 is such a great value. The airflow technology in the cylinder heads and intake system alone makes the engine package a hot rodder’s dream. The brain trust that developed the port, seat and chamber profiles deserve wide applause. Congrats on a job well done all.

Richard

 

Holy crap! That is some serious airflow!

 

Which engines will these heads fit?

 

Yeah, those heads flow exceptionally, especially for a stock head.

 

These heads are made by The General for the new C6 ZO6 cars equipped with 427cid engines. They're factory rated at 505fwhp. They're one tough hombre

Richard

 

I would like to have aset of these heads made for a smaller bore(3.905).

 

What size valves do they use? Looks like you need some big cubes to use that much air. Awesome numbers though for a stock head.

 

Thanks Richard. What I was asking was are they usable on other engines. Like a 5.3 or 6.0. But I didn't ask that did I

 

2.20 in /1.61 ex

 

WOW, That is some serious air! This head looks very interesting, I know it has a different port shape. I think it has a 12* valve angle also.