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#1
04-18-2011, 02:23 AM
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Guessing game... M/T hemi flow-test
To further our knowledge-base of port flow of various Pontiac heads, Jim Robertson of R.A.C.E. has generously volunteered to put my spare M/T hemi head onto his SuperFlow bench. The delay has been at my end, since the head was only partially machined and it has taken me awhile to do some machining, install guides and seats, etc., but the head will finally arrive at the R.A.C.E. shop this week.
So- let's have fun trying to estimate (or guess!) what sort of flow numbers we'll see.  I won't bore you with all the details, but valve sizes are 2.00" INT and 1.94" EXH. One as-cast intake port will be flowed, and one intake that I've named "M/T hemi wide-port" (see photo). Exhaust is pretty much as-cast, with just bowl blending and guide massaging. At my request, Jim will get data on a 4.020" bore fixture, but will also do some testing on a larger bore. Due to hemi valve-collision considerations, flow beyond about .700" lift is not of interest. No guesses from me... my limited exposure to flow-testing has taught me just one thing- that I can't tell by eyeballing an item whether it's any good or not!
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Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) |
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#2
04-18-2011, 02:34 AM
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Very cool! I look forward to the results.
I'll guess 370cfm at .700"
__________________
James 1970 Trans Am Spotts Built 484" IA2, Highports, EFI Northwind Terminator X sequential EFI fabrication and suspension by https://www.funkhouserracecars.com/ |
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#3
04-18-2011, 08:29 AM
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Ought to be interesting Jack !! Looks like a very short straight shot to valve opening ....
A wide port huh ??  Thanks for lending your MT head...Hope to see ya at Norwalk Jack...
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 ECM member. 2008 Outlaw Pontiac Drag Series Champion MANDRA Do it now fool! Life is short. 69 Grand Prix/3163lbs / IAII 535 w/ Tiger heads by Gaydosh....9.35@ 144 so far.. through mufflers. 1.26 60'. Going back to track with pump gas engine.... My 60 Ventura retired to street/strip duty.. |
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#4
04-18-2011, 08:42 AM
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Looking forward to working with Jack on this one as well as holding a piece of Pontiac racing history. It will without a doubt be interesting.
Cool. |
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#5
04-18-2011, 09:09 AM
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382 cfm stock and 410 cfm modded at 28" of water (Large Bore)
(Forgot to add that, 4.020" bore will choke up head). Tom Vaught
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. Last edited by Tom Vaught; 04-18-2011 at 10:04 AM. |
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#6
04-18-2011, 10:01 AM
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330 and 360 intakes and 280 exhaust
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#7
04-18-2011, 01:12 PM
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No guesses from me Jack, like you, I can't tell by looking. Even as cast the ports look plenty big for a 2" valve. Of course I don't think anyone would use these heads without a blower. Is there a way to check boosted flow?
Rob...
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" Darksiders Rule "
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#8
04-18-2011, 02:42 PM
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Quote:
ENGINES MAKE POWER BASED ON MASS FLOW which is why the density of the air makes a difference on a NA engine. Tom Vaught
__________________
"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
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#9
04-18-2011, 04:05 PM
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What's the Flow with the Intake Valve installed upside down (just-a-stem = removed)?
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#10
04-18-2011, 07:00 PM
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I will take a stab at the Intake flow volume and say 312 CFM @28".
An I am assuming the valve stem on that 2.00" Intake is 11/32". With out looking at the exh port in person I dare not even guess!
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#11
04-19-2011, 12:39 AM
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Valves are 3/8" stem (no undercut) from Ferrea.
Tom V- chambers are machined to 4" diameter. J.C.- if the EXH flows in the neighborhood of 280 CFM @ 28 in. water-  But I promised to not guess...
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Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) Last edited by Jack Gifford; 04-19-2011 at 12:57 AM. |
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#12
04-20-2011, 01:27 AM
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the winner...the one that guesses closest wins the head?
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#13
04-21-2011, 11:54 PM
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Head and parts arrived today. This is a neat piece and holds a special place in Pontiac history. Thanks Jack, for sharing this with the racers.
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#14
04-22-2011, 08:05 AM
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[QUOTE=pontiac jack;
J.C.- if the EXH flows in the neighborhood of 280 CFM @ 28 in. water- But I promised to not guess...[/QUOTE]put me in at 300 if the exhaust has been worked on, if as as cast, still 280... |
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#15
04-22-2011, 11:07 PM
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Jack, Do you have an as cast pic of the intake and exhaust that you could post?
Has anyone ever raced with these N/A?
__________________
66 Gto 65 Gto |
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#16
04-23-2011, 01:52 AM
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I have no knowledge of any N/A M/T hemi ever being run. I'm not saying there weren't any- Mickey made (and presumably sold) at least a couple of sets of port injectors for the hemi heads. And maybe a couple of dual-quad manifolds, I can't remember for sure.
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Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) Last edited by Jack Gifford; 04-23-2011 at 02:07 AM. |
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#17
04-23-2011, 01:56 AM
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Quote:
__________________
Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) |
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#18
04-23-2011, 02:03 AM
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I don't have much for pictures. Here's a view looking into an as-cast exhaust port (merely bowl-blended to the throat).
__________________
Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) |
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#19
04-23-2011, 12:10 PM
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If Jack says Go...I will start posting some pics as we capture them and work our way around these.
Jack, Do you have any pics of the rockers you use on yours? The more pics the better... Who made yours? |
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#20
04-23-2011, 12:28 PM
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Interesting. I am curious why you have not digitized a head and started widdling them out? Eventually casting and selling?
Having M/T designed Hemi head available I am sure would bring interest.
__________________
68 Firebird Are you running with the wind or breaking it? |
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