08-02-2017, 10:58 AM | #1 |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
GM CNC heads Flow Tested.
I got my hands on a set of GMPP CNC ported heads today and I am going to flow them against my heads later today when I get home.
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
Last edited by PRAY; 08-03-2017 at 04:47 AM. |
08-02-2017, 11:48 AM | #2 |
|
Wow, thank you for doing this!
__________________
It's been fun, done with GM.
2018 Camaro ZL1 (SOLD) - Blown Airbags 2017 Camaro SS F1FTY Member Journal (SOLD) - Bad Motor |
08-02-2017, 02:35 PM | #3 |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
Okay, as usual, back to back unbiased results. I pulled the GM head off and put my head on. It is hot as hell in my garage and I had just about every outlet running so I couldn't get a whole lot of depression out of my bench today. This was also a stock valve to stock valve test as well. So this is simply a runner contest. My custom cut intake valves are worth about 10cfm on my bench. I simply don't have any cut valves on hand for this test.
This test was done on my SF-110 flow bench, not a SF-600. So the flow numbers are going to seem low. I will label each head and runner and the depression each was flowed at. The SF-110 favors velocity over force to get around the valves. So runner size / shape and short turn become critical. At 28" you can get away with ALOT of errors in your sizing and velocity. I usually gain about 30cfm on a SF-600 flow bench at 28". This is how the flow bench data turned out. I did not CC the GM runner. If I get time I will see if I can get it poured. Test was done on a 4" bore with a clay radius inlet and a 2"x4" exhaust extension. ...................PRAY Int......GM Int..../...................PRAY Exh......GM Exh Dep....Lift..................................../.Dep....Lift................................... 12"....300"...........214..........204.../.15"....300"............180...........165 8"......400"...........273..........264.../.12"....400"............228...........225 7"......500"...........320..........306.../.10"....500"............251...........249 5"......600"...........350..........328.../.10"....600"............258...........258 I have to eat some crow on the GM exhaust port. It did suck at .300 and it was turbulent as crap at .400 so I had to get a best case bump for it's number. I couldn't get it to settle at all. But at .500 and .600 it was moving some air. I would like to see how it does at 28". I think it would be limited by size once the volume picks up. I am going to mess with the throat diameter of my exhaust seat/bowl to see if I can gain another 10-12cfm up top. I keep it really small and radiused to pump up my .100-.300 numbers. I have to find a happy medium.
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
|
08-02-2017, 03:30 PM | #4 |
Drives: Garnet Red - 20 ZLE Join Date: Jun 2016
Location: Southern California
Posts: 1,010
|
Once again, proves to myself I made the right decision. Thanks for the data.
|
08-02-2017, 03:36 PM | #5 |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
Once your heads had the valves done they flowed a bit better. These heads will too when I am done with them. I worked over some ports on the heads you sent back to compare to the GM head.
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
Last edited by PRAY; 08-03-2017 at 04:51 AM. |
08-02-2017, 03:44 PM | #6 | |
Drives: Garnet Red - 20 ZLE Join Date: Jun 2016
Location: Southern California
Posts: 1,010
|
Quote:
|
|
08-02-2017, 03:48 PM | #7 |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
I have them off of my bench. They are +/- 3cfm or so from my heads. I work my ass off to maintain consistency from set to set. If you are going to post numbers somewhere just use the 28" numbers I posted from my heads.
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
|
08-02-2017, 03:51 PM | #8 |
Hot Dog
Drives: '17 1SS 1LE Join Date: Feb 2016
Location: Metro Detroit
Posts: 1,937
|
PRAY delivers yet again on the Datagazm, thank you!
It's really great to see some back-to-back data. It for sure proves you not only know what you're talking about, but that you're humble enough to admit when you see room for improvement too. Two big thumbs up. I really look forward to when you're back in the game, because now I more than ever want some PRAY-ported heads on my 1LE.
__________________
2017 "M1SS1LE" in Hyper Blue w/PDR
|
08-02-2017, 03:59 PM | #9 | |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
Quote:
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
|
|
08-02-2017, 09:13 PM | #10 |
Drives: Camaro Join Date: Apr 2009
Location: Texas
Posts: 1,669
|
The gm heads are nothing to do with PRC. Just send a email or call and ask. No need to spread false rumors!
|
08-03-2017, 11:16 AM | #11 |
Drives: '16 2SS / '05 SRT10 Ram / '65 bu Join Date: Dec 2015
Location: Philthy
Posts: 978
|
Appreciate you putting in all the work homie. Knowledge is power....well, in our case horsepower...hmmm maybe that was the original saying (begins to ponder origins). Anyways, your posts don't go unnoticed bro so keep 'em coming.
I did inquire about a set of heads in the spring and I am still interested, I was just hoping to get my diff swap results next month, and a 10 second slip, before I crack the motor open. Consider me still in line.
__________________
H/C SBE 9.80@140 powered by Texas Speed
|
08-03-2017, 02:08 PM | #12 | |
Drives: 2016 2SS Join Date: Jul 2016
Location: Sanford NC
Posts: 2,766
|
Quote:
__________________
2016 2SS. H/C SBE 1.37 60ft, 6.36@109.49, 9.97@136+. Nuff Said.
|
|
|
|
Post Reply
|
|
|