Heads Are Ported, Polished and Flowed, and Larger Valves Are In: 324 CFM
#1
04-25-2006, 04:09 AM
Join Date: Jul 2003
Location: Missing in action
Posts: 2,803
Rep Power: 213 
Heads Are Ported, Polished and Flowed, and Larger Valves Are In: 324 CFM
The porting and polishing of my heads and intake manifold is finished and EVOMS is putting my engine back together. Ferrea custom fabricated new, larger valves for me – 39 mm intake and 34 mm exhaust. Technovance fabricated new seats and value guides.
It is amazing how restrictive the stock heads are, and how much excess material can be removed from the heads in order to increase flow. I have posted before and after photos below.
At 500 value lift, using 28 inches of water, my intake flowed 324 cfm, and my exhaust flowed 296 cfm. At 25 inches of water (25 and 28 inches are the most common benchmarks), that translates to 306 and 280 cfm (the conversion multiplier is .945 – here is the conversion table: http://highperformancepontiac.com/tech/0210hpp_flow09_zoom.jpg ; http://www.lindseyracing.com/flowpic...on%20Chart.jpg ). The full print out of my head flow test is set forth below.
I did some research regarding flow rates for other ported/performance heads. It appears that anything over 220 cfm is considered strong for domestic V8s/V10s. For example, ported/upgraded Viper heads from Hennessey and BTR flow 261 cfm (at 500 lift): http://www.btrviper.com/comparison.html . I recognize that flow rates for V10 engines may not be a meaningful reference for comparison purposes, but I nevertheless found the data interesting.
With the additional air flowing through my heads, I now have to upgrade my fuel system yet again (I already have the upgraded fuel system incorporated into EVOMS’ GT800 package). Now, we are going with an external, even stronger fuel pump, an upgraded fuel pressure regulator, larger return lines, and a couple of additional upgrades.
My heads should now flow more air than I need to achieve my performance goals.
Before:
After:
Flow Test Results:
After a short visit to its mother country (Germany), my transmission is back on Amercan soil, and will be delivered to EVOMS on Tuesday. Thus, it appears that my car is close to being finished.
Craig
It is amazing how restrictive the stock heads are, and how much excess material can be removed from the heads in order to increase flow. I have posted before and after photos below.
At 500 value lift, using 28 inches of water, my intake flowed 324 cfm, and my exhaust flowed 296 cfm. At 25 inches of water (25 and 28 inches are the most common benchmarks), that translates to 306 and 280 cfm (the conversion multiplier is .945 – here is the conversion table: http://highperformancepontiac.com/tech/0210hpp_flow09_zoom.jpg ; http://www.lindseyracing.com/flowpic...on%20Chart.jpg ). The full print out of my head flow test is set forth below.
I did some research regarding flow rates for other ported/performance heads. It appears that anything over 220 cfm is considered strong for domestic V8s/V10s. For example, ported/upgraded Viper heads from Hennessey and BTR flow 261 cfm (at 500 lift): http://www.btrviper.com/comparison.html . I recognize that flow rates for V10 engines may not be a meaningful reference for comparison purposes, but I nevertheless found the data interesting.
With the additional air flowing through my heads, I now have to upgrade my fuel system yet again (I already have the upgraded fuel system incorporated into EVOMS’ GT800 package). Now, we are going with an external, even stronger fuel pump, an upgraded fuel pressure regulator, larger return lines, and a couple of additional upgrades.
My heads should now flow more air than I need to achieve my performance goals.
Before:
After:
Flow Test Results:
After a short visit to its mother country (Germany), my transmission is back on Amercan soil, and will be delivered to EVOMS on Tuesday. Thus, it appears that my car is close to being finished.
Craig
#3
04-25-2006, 05:02 AM
Basic Sponsor
good to here.... my stuff is coming along as well.
__________________
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
#5
04-25-2006, 10:02 AM
Originally Posted by Craig
The porting and polishing of my heads and intake manifold is finished and EVOMS is putting my engine back together. Ferrea custom fabricated new, larger valves for me – 39 mm intake and 34 mm exhaust. Technovance fabricated new seats and value guides.
It is amazing how restrictive the stock heads are, and how much excess material can be removed from the heads in order to increase flow. I have posted before and after photos below.
At 500 value lift, using 28 inches of water, my intake flowed 324 cfm, and my exhaust flowed 296 cfm. At 25 inches of water (25 and 28 inches are the most common benchmarks), that translates to 306 and 280 cfm (the conversion multiplier is .945 – here is the conversion table: http://highperformancepontiac.com/tech/0210hpp_flow09_zoom.jpg ; http://www.lindseyracing.com/flowpic...on%20Chart.jpg ). The full print out of my head flow test is set forth below.
I did some research regarding flow rates for other ported/performance heads. It appears that anything over 220 cfm is considered strong for domestic V8s/V10s. For example, ported/upgraded Viper heads from Hennessey and BTR flow 261 cfm (at 500 lift): http://www.btrviper.com/comparison.html . I recognize that flow rates for V10 engines may not be a meaningful reference for comparison purposes, but I nevertheless found the data interesting.
With the additional air flowing through my heads, I now have to upgrade my fuel system yet again (I already have the upgraded fuel system incorporated into EVOMS’ GT800 package). Now, we are going with an external, even stronger fuel pump, an upgraded fuel pressure regulator, larger return lines, and a couple of additional upgrades.
My heads should now flow more air than I need to achieve my performance goals.
Before:
After:
Flow Test Results:
After a short visit to its mother country (Germany), my transmission is back on Amercan soil, and will be delivered to EVOMS on Tuesday. Thus, it appears that my car is close to being finished.
Craig
It is amazing how restrictive the stock heads are, and how much excess material can be removed from the heads in order to increase flow. I have posted before and after photos below.
At 500 value lift, using 28 inches of water, my intake flowed 324 cfm, and my exhaust flowed 296 cfm. At 25 inches of water (25 and 28 inches are the most common benchmarks), that translates to 306 and 280 cfm (the conversion multiplier is .945 – here is the conversion table: http://highperformancepontiac.com/tech/0210hpp_flow09_zoom.jpg ; http://www.lindseyracing.com/flowpic...on%20Chart.jpg ). The full print out of my head flow test is set forth below.
I did some research regarding flow rates for other ported/performance heads. It appears that anything over 220 cfm is considered strong for domestic V8s/V10s. For example, ported/upgraded Viper heads from Hennessey and BTR flow 261 cfm (at 500 lift): http://www.btrviper.com/comparison.html . I recognize that flow rates for V10 engines may not be a meaningful reference for comparison purposes, but I nevertheless found the data interesting.
With the additional air flowing through my heads, I now have to upgrade my fuel system yet again (I already have the upgraded fuel system incorporated into EVOMS’ GT800 package). Now, we are going with an external, even stronger fuel pump, an upgraded fuel pressure regulator, larger return lines, and a couple of additional upgrades.
My heads should now flow more air than I need to achieve my performance goals.
Before:
After:
Flow Test Results:
After a short visit to its mother country (Germany), my transmission is back on Amercan soil, and will be delivered to EVOMS on Tuesday. Thus, it appears that my car is close to being finished.
Craig
Thanks for the information. Here is something to compare with.
Flowed at 25” water. Inlet bell and Exhaust outlet used.
lift 0.050”, intake 52.3 cfm, exhaust 40.9 cfm
lift 0.100", intake 97.5 cfm, exhaust 92.2 cfm
lift 0.150", intake 144.0 cfm, exhaust 144.7 cfm
lift 0.200", intake 194.0 cfm, exhaust 179.2 cfm
lift 0.250", intake 237.6 cfm, exhaust 204.8 cfm
lift 0.300", intake 272.8 cfm, exhaust 225.3 cfm
lift 0.350", intake 297.3 cfm, exhaust 238.7 cfm
lift 0.400", intake 310.7 cfm, exhaust 250.9 cfm
lift 0.450", intake 320.9 cfm, exhaust 259.2 cfm
lift 0.500", intake 324.5 cfm, exhaust 266.2 cfm
lift 0.550", intake 327.2 cfm, exhaust 272.0 cfm
The figures you show are for 28". Can you post the ones for 25". I don't have 28" information for my heads.
I guess the question now is what cams are you using? Especially important is the intake lift. S Car Go Racing now has special intake and exhaust cams for these cars which will really make use these heads.Our studies showed a 10 hp increase for every additional 10 thousands lift up to a certain lift at which point no additional gains were realized.
Last edited by cjv; 04-25-2006 at 10:14 AM.
#6
04-25-2006, 10:15 AM
Registered User
Join Date: Dec 2005
Location: Huntington Beach - CA
Age: 61
Posts: 1,200
Rep Power: 90
#7
04-25-2006, 11:20 AM
Basic Sponsor
On stock cams I believe u will still be under 8k rpms.... CJV, what will u be hitting up on top?
__________________
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
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I thought I said something unkind lol...
#14
04-25-2006, 01:59 PM
Registered User
Join Date: Oct 2004
Location: Richmond, VA
Age: 39
Posts: 715
Rep Power: 60
Craig, Now that the head is done, and the Transmission is back (did you end up using Renntech afterall?) when do you expect the tuning, etc, to be finished and to have the car back in your hands?
#15
04-25-2006, 02:21 PM
Join Date: Jul 2003
Location: Missing in action
Posts: 2,803
Rep Power: 213
Originally Posted by MARKSKI
On stock cams I believe u will still be under 8k rpms.... CJV, what will u be hitting up on top?
Craig