Repost from Engine section...

This is a Stage 1 head with stock valves.
INTAKE
.100 75.48cfm
.200 133.20cfm
.300 189.20cfm
.400 206.80cfm

EXHAUST
.100 63.64 cfm
.200 113.96cfm
.300 171.60cfm
.400 184.80cfm

Flowed at 28" air temp 96degrees with 60% humidity.

there are still more that can be had without cutting the plenum off and still keep things reliable. I have another head i will be doing over the next little bit so I will try a few more things.

 

Those numbers look about what is typical for a cummins head. Has anyone ever done any flow numbers using pressure (boost) instead of using vaccum? I've noticed that the truck is more responsive with a ported head and cam than when it was stock.

 

Never seen a bench that can deliver pressure. When you say typical, what numbers do you have for comparison, I cant find much. Whats a bit different on the numbers Ive seen is on this head the Intake is outflowing the exhaust, on Piers site the exhaust outflows the intake.... I know the bench is within 2 cfm, as we calibrated it before flowing.

 

On a side note with the head flow gains of 14 lb/min, you have a HX35 (63 lb/min) and you went to a HX40 (74 lb/min) you still wouldnt move as much air as a ported head w/ a HX35. Not to mention the cooler charge from the turbo not having to work as hard.

 

i can't wait to get it on the truck, but first i am going to fix my fuel issues.

 

I think that Piers has inputed the info backwards, as the intake should always out flow the exhaust. I think that there are a couple guys that do the head with pressure instead of vaccuum. You just need a good air compressor do to the test. How much material is left in the bowl? I have a spare 24v, I should try to hog one out for myself. I was lazy and bought my head. You planning on o-ringing the head? Its just extra insurance against head gasket failure. Good head studs is also a good idea. I've ran my truck to 65psi a few times, no issues so far.

 

Funny you mention the numbers are backwards on Piers site. I called them to confirm it and he insisted they are listed correctly, so that is kinda spooky.

Theres enough in the bowl and elsewhere as well as I may do something I thought of before I give the head back to gunracer1, and he is planning on o-ringing it. Im confident in another 8-10 cfm without getting to nutz.

BTW, what did you pay for a head and what all was done to it?