How do my flow numbers look?

[PHANTASM]

i did a port match and bowl clean up.
don't really know if these numbers are any good.
i didn't hog the runners out, just cleaned up the bowls and smoothed the short turns on the intake and exhaust.

stock 8445 heads:

intake (stock valve w/30* backcut)

.100 60cfm
.200 118
.300 149
.400 161
.500 163
.550 163


exhaust (stock valve w/30* backcut)

.100 68cfm
.200 106
.300 137
.400 153
.500 158
.550 161

 

[SHADOWII]

You have...

the #'s moving in the right direction! The stock #'s, if I remember correctly, are around 140's and 120's. Others will jump in w/more definitive #'s.

 

[turbofabricator]

Why not straighten the ports out? You're almost there. Also, remember we dont race flow benches. They are a tool only and they don't always reflect accurate info. Turbochargers cover lots of mistakes in port work. If you were to flow a head at flow levels at 20psi boost, you would need a flow bench capable of 1,000+ inches of depression. Make the intake port volume as big as you can with out killing low lift flow and it will make more power. The valve job will detirmine low lift flow numbers along with a good bowl work.

 

[PHANTASM]

I AM GOING TO WORK THE SHORT SIDE RADIUS SOME MORE IN the intake and exhaust and work the intake a little more in the runner and guide area.
have really touched much in the intake other than the bowl area.

thanks for the feedback. i appreciate it.

 

[PHANTASM]

I flowed another set of ports and am within 5cfm of the other ones.

i also flowed them with stock cut valves and noticed the backcut intakes and exhausts were worth at least 10cfm until the .450 and up mark then not so much.

i opened up the bowls a little more and tried a different valve job with a narrower seat by about .010 less. i will test that and see what happens.

there sure is alot of testing and labor involved porting heads.

 

[bison]

Leave the ex alone. Your 90%there. The intake needs a lot of work. The short turn will increase flow a lot there. You should stall around .500

 

[bison]

Why not straighten the ports out? You're almost there. Also, remember we dont race flow benches. They are a tool only and they don't always reflect accurate info. Turbochargers cover lots of mistakes in port work. If you were to flow a head at flow levels at 20psi boost, you would need a flow bench capable of 1,000+ inches of depression. Make the intake port volume as big as you can with out killing low lift flow and it will make more power. The valve job will detirmine low lift flow numbers along with a good bowl work.

Turbochargers will not cover up poor flowing heads. You can see the difference when you attempt to race someone with a set of properly ported heads and run the same boost levels on an otherwise similar combo. You are also wrong about port flow. There can be 30psi in the runner and it will still flow nearly the same cfm as if it had 2psi in it. The only difference would Be in the overlap period where these engines are typically losing flow because of high residual cylinder pressure as the intake is opening and the ex is closing. Density and flow are two totally separate things. Increasing low lift flow on production style heads will always leave room for extreme power potential.

 

[PHANTASM]

Final numbers

well i think i have done all i want to do to these heads.
the intake picked up some.

final numbers are:

intake

.100 62 cfm
.200 118
.300 156
.400 172
.500 175

exhaust

.100 52
.200 102
.300 135
.400 148
.500 152

not sure why i lost a few cfm on the exhaust. really didn't do much more to it. probably the flow bench?
i wonder if some better valves would benefit me?

hopefully they work out. can't afford to pay someone professionally and champions or gn1's are out of the budget right now.

wish me luck

 

[pajo]

+

good job brother , this should a notecable differance ..

 

[PHANTASM]

thanks. i like to share the info with people hopefully it helps someone.

 

[PHANTASM]

WELL I DID ANOTHER SET OF HEADS. these have a stock valve with a back cut on both intake and exhaust.
there was no exhaust tube used in the testing and no radius to the intake port

FINAL FLOW NUMBERS ARE AS FOLLOWS:

intake

.100 53 cfm
.200 113
.300 151
.400 170
.500 180
.550 185
.600 188


exhaust:

.100 46 cfm
.200 97
.300 125
.400 144
.500 151

anyone think i would gain much by going to a better valve?