Here’s some results of a recent flow test of a #317 casting. The head looked to be pretty average as far as core shift goes. I tested the two center cylinders. Interesting to note how the second intake port tested flowed extremely well to .450” lift, then settled back down to it’s peak average. The test was performed on a SF600 flow bench.

Lift___Cyl1Int.____Cyl2Int.____Cyl1Exh.____Cyl2Exh .___Cyl2Exh w/out pipe
.100___64.8_______65.9_______56.6_______57.1______ ___53.3
.150___101.7______103.9______92.1_______92.1______ ___87.8
.200___142.1______141.8______113.1______116.1_____ ___111.6
.250___177.7______177.1______133.8______139.4_____ ___131.8
.300___204.3______203.4______152.1______157.8_____ ___146.8
.350___224.3______224.9______159.8______165.8_____ ___157.1
.400___233.5______242.9______171.6______175.8_____ ___164.9
.450___241.4______252.5______181.2______184.8_____ ___166.8
.500___250.0______247.0______190.6______200.4_____ ___174.2
.550___251.2______250.9______197.9______200.1_____ ___181.2
.575___253.0______251.1______199.3______202.1_____ ___183.0
.600___253.0______251.9______200.4______203.0_____ ___184.4
.625___252.2______252.2______200.9______204.1_____ ___184.8
.650___253.1______252.2______201.7______205.2_____ ___185.3

Intake runner volume = 208.5cc
Exhaust runner volume = 77.0cc
Combustion chamber volume = 72.4cc
Test bore dia. = 4.030”
The intake ports were tested with a radius flow plate and cyl. #1&2 exhaust ports were tested with a 2.0” stub pipe.

As soon as I get an intake manifold, I'll edit the post with the results.

Richard

 

Thank you Richard.

 

way to go Richard

Nice to see a company so dedicated to the trucks
we need more like you
Keep up the good work!!

 

Hey Richard,

If you get around to testing out some of these heads
with the truck intake on, let us know. I'm more than
interested in this.

Thanks.

 

Good post Richard. Thanks.

Interesting how the flow basically flattens out at .500 lift for both intake and exhaust. Basically no change in flow all the way through .650 lift.

 

can you put 6.0l heads on the 5.3l?

 

Yes, but it will drop the compression about a point.

 

Great info, thanks again Richard

 

Can the point be regained by shaving the head.... without messing up valve train alingment?

 

It would take a milling of .060" to remove the 10cc necessary to get to the 5.3l chamber volume. That would cause some issues with pushrod length and possible intake manifold fit.

Richard