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Stock Hemi head flow...I had no idea how good #750272
07/17/10 09:52 AM
07/17/10 09:52 AM
Joined: Jan 2003
Posts: 3,103
Phila Pa
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scatpacktom Offline OP
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scatpacktom  Offline OP
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Joined: Jan 2003
Posts: 3,103
Phila Pa
Recently I was able to buy some Hemi parts from a friend of a friend. The guy is a early B body/Max Wedge fan that along the way had picked up some Hemi parts with the intent of building a 64 Hemi Plymouth clone.

So Joe had some later 66 and up stuff too. Joe tells me his buddy had a machine shop and his buddy retired. In the shop there he had some 1966 Hemi cylinder heads that a customer dropped off 30 years ago and never came back for. Joe bought them from his buddy. Joe realized he wasn't going to be building any Hemis so I got a call.

One of the heads has had guide liners and a valve job, the other is a virgin original head. As in Chrysler valve and valve job never monkied with AND in good condition. I passed these heads off to Dwayne Porter in the spring to be freshened up. The other day he had them on the flow bench. At .470 valve lift they flow 280 cfm with the stock valve job and valve. That is as good as my best ported wedge head at .600 lift. At .600 lift the Hemi heads flow 299 cfm. The low lifts crush the wedge heads too.

You would always hear rumors about some guy back in the day that would throw some 4.88s,headers,rat roaster,3/4 race cam and some big slicks and go out and run in the tens with a otherwise stock Hemi. With heads that flow like that I believe it! Some bad ass stuff for 1960s technology.

I don't have the heart to mess with them. I'm not going to deck'em or port them for the sake of it. I think I'd have a hard time coming up with a nicer set at any cost. Dwayne told me about when the Mopar Performance heads came out all the stocker guys were upset that they weren't as good as the originals. At the time he thought it was BS. Now we have the hard facts as he has had some MP heads across the bench. In some lifts they are 20 cfm down from the original castings!

I realize to most of you guys out in the internet land these numbers are just numbers,keep in mind that I have had multiple sets of cylinder heads done and flowed by Dwayne. So to me I can compare the numbers of my other heads to these.

I thought it was intresting is all.

Re: Stock Hemi head flow...I had no idea how good [Re: scatpacktom] #750273
07/17/10 09:56 AM
07/17/10 09:56 AM
Joined: Jul 2010
Posts: 1,491
Oologah, Oklahoma
Big Squeeze Offline
pro stock
Big Squeeze  Offline
pro stock

Joined: Jul 2010
Posts: 1,491
Oologah, Oklahoma
Thanks, for sharing Tommy......That's cool info.......


If you can't handle the truth, you're living a lie.......
Re: Stock Hemi head flow...I had no idea how good [Re: Big Squeeze] #750274
07/17/10 10:11 AM
07/17/10 10:11 AM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline
I Live Here
Dragula  Offline
I Live Here

Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
I have run iron heads that looked nearly stock and flowed more than my current Indy 426-1 heads....It takes a bit to beat those old numbers with factory heads from that era, but now a days, a small block phord head will just about flow what the newer hemi heads will. Just scary.

Currently, mine flow right about 395cfm and it comes on real quick...just not exactly where I wanted to be, a little disapointing, but I am not paying huge $$$ to have someone else work on them for now.

Last edited by Dragula; 07/17/10 10:12 AM.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Stock Hemi head flow...I had no idea how good [Re: Dragula] #750275
07/17/10 10:33 AM
07/17/10 10:33 AM
Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
HEMIFRED Offline
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HEMIFRED  Offline
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Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
back in the day a simple 5 angle valve job done as per direct connection info would keep you competitve in any class. very little if any other work was allowed in stock or super stock back then.


home of the
Sox and Martin Hemi Duster


Re: Stock Hemi head flow...I had no idea how good [Re: HEMIFRED] #750276
07/17/10 12:23 PM
07/17/10 12:23 PM
Joined: Sep 2008
Posts: 2,840
Flint, Michigan
B1Fish540 Offline
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B1Fish540  Offline
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Joined: Sep 2008
Posts: 2,840
Flint, Michigan
I think thats how the old saying started, "If a hemi gets in front of you the race is over.." or something to that effect. They just keep pulling. The new 3rd gen hemis flow great out of the box too.

Re: Stock Hemi head flow...I had no idea how good [Re: scatpacktom] #750277
07/17/10 12:30 PM
07/17/10 12:30 PM
Joined: May 2005
Posts: 6,446
NJ-USA
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HPMike Offline
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HPMike  Offline
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Joined: May 2005
Posts: 6,446
NJ-USA
Quote:

You would always hear rumors about some guy back in the day that would throw some 4.88s,headers,rat roaster,3/4 race cam and some big slicks and go out and run in the tens with a otherwise stock Hemi. With heads that flow like that I believe it! Some bad ass stuff for 1960s technology.

I




That was exactly how my 71 Challenger was set up. Stock stroke. 4.88's. Unported heads. Racer Brown cam, Tank heavy slipper skirt pistons. Synchronized tranny with super shifter setup. Mildly modded RR intake and Comp series carbs. Hookers, slicks, etc. Untouched body.

Ran best 10.40's

MB

Re: Stock Hemi head flow...I had no idea how good [Re: HPMike] #750278
07/17/10 01:30 PM
07/17/10 01:30 PM
Joined: Jul 2006
Posts: 4,177
California
mickm Offline
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mickm  Offline
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Joined: Jul 2006
Posts: 4,177
California
these are my numbers. they are mopar aluminum heads, probably purchased in 2005 or something like that, so not the new edelbrock castings.

before:

In Ex
.300 213 198
.400 254 205
.500 276 205
.600 287 205
.700 290 205

after a mild port job:

In Ex
.300 235 225
.400 284 229
.500 317 232
.600 329 234
.700 337 236

pretty easy to see that these heads flow similar or worse than stock heads. hard to imagine they would put all the effort into casting a head, and not even improve the one critical issue: flow.

anyway, just for comparison.







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