|
Guessing game... M/T hemi flow-test
1 Attachment(s)
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! |
Very cool! I look forward to the results.
I'll guess 370cfm at .700" |
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... |
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. |
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 |
330 and 360 intakes and 280 exhaust
|
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... |
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 |
What's the Flow with the Intake Valve installed upside down (just-a-stem = removed)?
|
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! |
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- :eek: But I promised to not guess... |
the winner...the one that guesses closest wins the head?
|
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.
|
[QUOTE=pontiac jack;
J.C.- if the EXH flows in the neighborhood of 280 CFM @ 28 in. water- :eek: 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... |
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? |
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.
|
Quote:
|
1 Attachment(s)
I don't have much for pictures. Here's a view looking into an as-cast exhaust port (merely bowl-blended to the throat).
|
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? |
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. |
| All times are GMT -4. The time now is 12:34 AM. |