Flow on 392 stock heads?

Discussion of the 331-354-392 HEMIs.

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Flow on 392 stock heads?

Postby Moparlee » Wed Feb 16, 2005 7:50 am

I can't remember if I've asked this or not. Has anybody had their heads flowed. I would like to know if the 392 heads can achieve 285 CFM once ported? Thanks for your time.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
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Postby firepower354 » Fri Mar 11, 2005 11:15 pm

Not very likely, even with big valves, necked down stems, trimmed guides and ports hogged just shy of water. The ports just aren't big enough. I'm sure there are racers getting close with 555's maxed out, but I doubt much over 260 for a full on 392.
Crank up the boost till you run over the crank!
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Postby Moparlee » Fri Mar 18, 2005 12:59 pm

That doesn't seem like much. You compare them to a sb mopar cylinder head and the ports are huge. Here are some flow numbers from http://www.shadydellspeedshop.com/jhead.htm
FLOW #’s

LIFT------ASCAST---------PORTED
.100”----62.1/46.6---------62.1/51.8
.200”----112.1/99.4-------135.2/103.5
.300”----156.6/128.3-----198.7/135.2
.400”----193.2/137.3-----239.8/158.7
.450”----200.1/138.3-----253.9/169.7
.500”----200.1/139.7-----258.4/182.9
.550”----200.1/140.8-----264.9/186.3
.600”----200.8/141.5-----254.6/186.3

All #’s at 28” of Water
2.02”/1.60” MP Stainless valves

This what Hot Heads has on there website:
Valve Lift (Which heads I'm not sure cause it doesn't say? Like are the 555 or the 392?)
(Intake) .200 .300 .400 .500 .600
Stock: 121 178 212 225 233

Valve Lift
(Exhaust) .200 .300 .400 .500 .600
Stock: 97 128 145 159 160

If I'm not mistaken then they flow what a big block mopar head flows, not ported.
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
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Postby firepower354 » Fri Mar 18, 2005 7:08 pm

233@ .500 from a stocker is a far cry from 285. The hemi ports are large at the entrance but the floors rise up to make the ports almost square near the turn. The total area of the restricted portion is smaller than the ported "J" heads in the link. Adding the bigger valve probably hurt their as-cast Js, making the porting look even better. Without the proper relationship of valve head to bowl diameter, flow suffers. The hemi is unlikely to pick up as much as the later wedges due to the smaller bowls and the port area. I put 2.08 valves and a pretty serious port job on a set of 354 heads when I was at Batten and they never approached 285. They are cool engines but the early hemi isn't optimized for airflow.
Crank up the boost till you run over the crank!
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Postby Moparlee » Mon Mar 21, 2005 8:23 am

Well, thanks for your time, Firepower354.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
Moparlee
 
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need more info

Postby johnny5 » Wed Dec 07, 2005 10:55 pm

It would be nice to see some recent flow numbers on stock and ported heads. The wizardry of building a big hp early hemi hasn't been documented very well over the years. Nobody has numbers to back up their claims. I doubt there's much (if any) difference betwen a 1955 triple-nickel head and a 1956 354.
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Postby Moparlee » Fri Dec 09, 2005 1:34 pm

I would like some updated flow numbers also. I think when I get the money to build the 392 that I will send them to Shady Dell to have Ryan port them for me. He ported my sb eddy's for my 340.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
Moparlee
 
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truck heads?

Postby johnny5 » Sat Dec 31, 2005 8:11 am

I've got a 331 truck motor with the 'big pig' heads with the stupid water x-over in the middle. They're suppopsed to be a little thicker and stronger than car heads but the water port forces you to use the Weiand 2x4 intake or weld up the x-over ports. I haven't decided on the intake situation yet, but if I can find a shop with a flow bench around here I might just do a before and after comparison of the numbers.

Chrysler powertrain engineers have always been kinda lazy when it comes to changing internal designs. The outside casting may look different, but I bet the ports are exactly the same as a 1954 331 hemi head that the 1955 head was based on. The only difference between 1954 & 1955 331 car heads is the water passages cast in the ends.

I've owned all of the different styles of low-deck 331/354's at one time or another. They all looked virtually identical when it came down to the ports. The nostalgia guys didn't really seem to prefer one over the other either. I'll post this when I get it done but cash is tight until I sell my 438 stroker motor (383 bored to 4.31 w/440 steel crank, aluminum heads, fully streetable, done to the 9's). It's $5650 sacrifice price if anyone out there's looking.
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Postby firepower354 » Sat Dec 31, 2005 8:33 am

The truck heads I've seen have insert seats and an ugly ridge in the short turn. I plan to use them anyway, after a few hours under the carbides of course.
Crank up the boost till you run over the crank!
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Postby johnny5 » Sat Dec 31, 2005 11:17 am

What do you plan on using for an intake? Another idea I've been kicking around is to use a Hot Head 4bbl and weld the tabs on the face to cover the x-over ports. At the same time I'de probably fab up a t-stat housing to make it fit like a stocker.
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Postby Bailiesdad » Mon Jan 09, 2006 6:56 pm

johnny5 wrote:What do you plan on using for an intake? Another idea I've been kicking around is to use a Hot Head 4bbl and weld the tabs on the face to cover the x-over ports. At the same time I'de probably fab up a t-stat housing to make it fit like a stocker.


Go with a Hilborn Injector and forget about carbs... :D
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Postby johnny5 » Wed Jan 11, 2006 10:15 am

Very cool, but it still doesn't cover the truck head water port. I had an Enderle setup a few years back that didn't have the extra hump in the middle. Is the Hilborn the same?
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flow numbers on early heads

Postby budmspeeco » Sun Jul 09, 2006 2:05 am

Look at what D>A>D> is saying they are getting from the littlest heads hemis had on auction# 140002455609 . Impressive or blowing smoke to sell an inferior product, a head no one wants to use. Any comments?
'48 anglia
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Postby johnny5 » Sun Jul 09, 2006 6:11 am

I saw those too. They didn't post any flow nubmers so I have to call BS. They were very nicely done though. 345 cfm is what pro stock heads like the Big Cheif and modified pro stock hemi hemi flow. I don't think the technology and port design of the day would allow for this.
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Postby Bailiesdad » Sun Jul 09, 2006 6:44 am

Ladds Porting Service probably can give you flow numbers on any hemi head. 410-799-1763
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Postby firepower354 » Sun Jul 09, 2006 2:38 pm

By BullS*$t, I mean it's not real likely. Not at 28 inches of water anyway. At 38 maybe. Just tweak the calibration adjusters to read what you want. It's what we call a "knob-job" in the airflow development industry. I can unscrew the adjuster on my bathroom scale far enough to say I still weigh the 215 I wrestled at in college despite the doc telling me I can play teeter totter with Warren Sapp. There isn't enough port area in a hemi, no matter who's spinning the carbides. PS truck smallblocks went over 400cfm(I personnaly saw Lingenfelters on our bench), BB's way more, but that's apples vs. aardvarks.
Crank up the boost till you run over the crank!
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torque of a hemi

Postby johnny5 » Sun Jul 09, 2006 2:51 pm

So, what you're saying is you need the power of a hemi more than most of us? (LOL)
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Postby firepower354 » Sun Jul 09, 2006 3:06 pm

Heck yeah! Power's good stuff. Half of the power to weight ratio equation is weight. I shave my head, dump the change from my pockets, I don't even wear socks. Fortunately my roadster's light enough I can roll it around like a rickshaw by grabbing the front frame horns(minus hemi, of course).
Crank up the boost till you run over the crank!
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Postby johnny5 » Sun Jul 09, 2006 4:48 pm

too funny :lol:
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flow numbers

Postby johnny5 » Sun Jul 09, 2006 5:38 pm

Back to the original topic, I found a 1955 331 to use as my stroker project so I sold the truck motor (sorry bud, I saw you were high bidder but someone came by with cash). I'll do a real, un-biased flow test on the heads. I don't know why they're called 555/triple nickel. The 5's are out of sequence :-?
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Postby Moparlee » Mon Jul 10, 2006 5:59 am

It would be cool to compare those tripple nickle heads to set of 392's. I know from hear say are books that they supposedly flow more than the 392's. I would like to know how much though, if any?

Lee
Last edited by Moparlee on Tue Jul 11, 2006 7:42 am, edited 1 time in total.
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
Moparlee
 
Posts: 144
Joined: Thu Jul 22, 2004 6:38 am
Location: Carthage, MO

Postby speedicusmaximus » Mon Jul 10, 2006 7:24 am

Hi,
The figures quoted earlier by "Moparlee" on from Hot Heads website are also in Tex Smith's Hemi book. The book doesn't state which (Hemi) heads the figures were obtained from in the book either. It does give comparison figures for "stock" (unported), and "street-ported" Hot Heads alluminum Hemi-heads, and quotes a figure of 416 cfm @ 0.700" lift, on 28" of water for "race-ported" H-H Hemi-heads.
Mike :-?
Beep ! Beep !
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Flow on 392 stock heads?

Postby budmspeeco » Mon Jul 10, 2006 8:05 pm

Maybe some of the advantage the old guys thought they saw in the 555 heads was not so much that the heads flowed better ,just that the chambers were 10 ccs smaller & they got a little umph from more compression by bolting them on 392s. Buddy
'48 anglia
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Postby Moparlee » Tue Jul 11, 2006 7:43 am

I wouldn't doubt that a bit. 10cc's is quite a bit.

Lee
392 Hemi
354 cracked and needs a sleeve
241 or 270 the only running one I have
340/E-brock heads/six-pack/4-speed/mini tubed/spool-64 Valiant
Moparlee
 
Posts: 144
Joined: Thu Jul 22, 2004 6:38 am
Location: Carthage, MO

Postby Bailiesdad » Thu Jul 13, 2006 7:13 am

If you place a 392 head, a 331 1556157 head, and 354 1619823 head side by side you can see the changes in the port that will allow more air flow.
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