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Head flow

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purple72Gremlin View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: May/08/2010 at 11:10am
Originally posted by trrowe trrowe wrote:

You don't have that much flow because Dean Turk didn't do your port work. When Don Garlits came out of retirement to attempt to break the 300 mph barrier he chose Dean Turk to do all the port work on his cylinder heads and manifolds. Thats how good he is. He has turned away work for years because he's always swamped with work. He will only do port work for true enthusiasts and always achieves the best flow numbers. Dean has been retired for many years, but still does the best port work in the country for a select few. He was a pioneer and early dominating force in the early 60's, First in a Pontiac powered Fuel dragster and later with a Crysler Hemi Fuel dragster.If you don't know of Dean, then you missed out on a truly fine human being that would be just as excited as you are to see you (and help with the best possible porting) tweak as much performance as possible out of your AMC.
 I'll never forget hearing a deafening roar from my shop, and running outside to see Dean smiling and tuning Eddy Hill's Top Fuel dragster right before Eddy retired.
 No finer cylinder head, intake manifold porting guru has ever lived. He always did extra work for the regular "Joe." especially if you wanted performance from a platform that wasn't the typical "performance" vehicle.
Thanks, Dean, Ed, Bill, Jerry.....
Did Mr Turk ever do an AMC??
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SuperStockAMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SuperStockAMX Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 1:22am
This "luxurywheel" that places Dean Turks ads recently had a pair of "Dean Turk NASCAR AMC NASCAR heads" on ebay. Super rare part, super expensive (I think it was $2500 starting bid) blah, blah, blah. They were standard passenger car heads (291 or 993 as I recall). I sent an email to luxowheel and politely mentioned I had a set of AMC Trapezoid NASCAR heads that look quite a bit different than what he was offering and if Dean wanted to drive north about 30 minutes he could take a look-see. I was told "that's what Dean said, he's the best, etc., etc."  
So maybe at one time they were bolted on a NASCAR AMC but I think most would agree there is a difference between the two. 
My -291's flow 303 CFM and I know Barry Allen and A.H. Adkins can come up at least the same if not better numbers (I assume better) but they're using larger valves than my 2.02" / 1.68" which are required in my class. I also have to maintain 175cc intake runners and 75cc exhaust runners per the class rules. The SS/B through SS/D 390 cross ram SS engine has larger valves and ports volume specs.  
Since my SS engine (1970 390 w/ Autolite carb) was built, NHRA has been more generous in what is acceptable with valve jobs. We'll be trying new valve angles and the numbers may improve. Probably only slightly, hopefully not worse! 
My machinist is Bud Yancer of MACH Development. That's Manifold and Cylinder Head Development. And while he has built some competitive Jeep off-road SCORE engines in the past, my heads are the most serious drag race factory AMC heads he has ever done. To suggest one has to be an AMC "guru" on anything related to the engine is nonsense in my opinion. Adkins did provide me with a 5 word clue that was really helpful so I'm glad we can all work together. 
So I would say based on what has been mentioned here, along with my own results and what I have spoken to with Adkins and Allen, it would appear low 300 CFM range is credible. 

What I would really like to know is some serious reporting on Trapezoid heads as they are a factory (although over the counter) cast iron cylinder head. I have the last design with the raised / large runner intake and trapezoid exhaust ports. I'd like info on runner volumes, valve sizes, chamber volumes and of course CFM ratings. I'd like to know what the numbers are on relatively stock or "as delivered" (or at least assembled without extensive work) vs. "built to kill". 
Some other day I will have a use for them. But not today. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hurst390 Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 8:19am
trap heads flow about 340 with a 2.08 valve...bigger valves 360cfm.....not bad for 35+ year old iron heads?
Ken Parkman made a port mold off mine a couple years ago in stock form...maybe he will chime in and share the pics compared to other runners he has molded?

Edited by Hurst390 - May/10/2010 at 8:47am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken_Parkman Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 10:05pm
Unfortunately we took that mold out too early so it lost some of it's shape. But it's still enough to show the trap head is big time different than a stock iron casting. The csa through the center where you can't make the stock head big enough has been fixed in the trap head - and how! It's way huge where it needs to be to properly feed a bigger valve. The volume is much larger than a stock head.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote beepbeep Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 10:48pm
Mr Ken Parkman, You've done a bunch of flowing on AMC heads. Whats your opinion concerning some of the CFM claims from AMC heads? Over the years we've heard some pretty big numbers but have never seen an actual flow test to back the numbers up. BB
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SuperStockAMX Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 11:21pm
Ken's opinion will be appreciated but if I may interject, CFM = HP, HP = MPH, numbers don't lie. You can't take one factor out of the equation and get the same results. This is of course relevant to a naturally aspirated engine. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote beepbeep Quote  Post ReplyReply Direct Link To This Post Posted: May/10/2010 at 11:49pm
What numbers are you suggesting don'nt lie?   
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SuperStockAMX Quote  Post ReplyReply Direct Link To This Post Posted: May/11/2010 at 1:14am
Using my own examples, my stock eliminator -291 heads (no porting allowed and I had 270 CFM intake flow with 165 cc intake runners against a 175cc spec) made 534 HP which runs in line with the 125 MPH runs I made @ 3160 #'s. 
Took another set of -291's for Superstock (porting allowed but stock valve sizes and 175cc runner volume spec) which are 303 CFM and the engine makes 635 HP and runs 132 MPH @ same weight. 
Ken can chime in with CFM to HP formulas but the bottom line is with no airflow you have no HP. With no HP you have no MPH. You can reverse formulate the probable flow of a set of heads if you know the MPH & distance. Math takes all the BS out of the bench talk. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote SKeown Quote  Post ReplyReply Direct Link To This Post Posted: May/11/2010 at 4:21am
 
 So, if I run 128 MPH @ 3150 #'s, I've probably wrung out the HP potential of 280 CFM heads? The thing that's confusing, Jim (Hurst390) claims his heads flow 290 something, but look at how fast he runs? Besides he's feeding more inches and isn't taking it easy on it either.
 
 SKeown  
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Hurst390 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Hurst390 Quote  Post ReplyReply Direct Link To This Post Posted: May/11/2010 at 7:52am
superstock do the math for us...2950# 145.11 mph 1320 ft....how many cfm?
Ken post those pics if you get a chance and don't mind...
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