Re: Hemi "nail head" valves?
[Re: INTMD8]
#2786822
06/18/20 02:03 PM
06/18/20 02:03 PM
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Joined: Oct 2007
Posts: 4,209 New York
polyspheric
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master
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New York
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IFAIK, this originally referred to the small head diameter valve used in 1953-66 Buick V8 engines. They may be referring to the head shape, or rather the stem-to-head radius, in which the head fits the stem like a "penny on a stick" or letter "T". This is the opposite of what hemi engines commonly use, the "tulip" valve with a big convex bell instead of a radius.
Boffin Emeritus
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Re: Hemi "nail head" valves?
[Re: INTMD8]
#2786888
06/18/20 04:28 PM
06/18/20 04:28 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
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I Live Here
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So. Burlington, Vt.
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I’m sure the blank they’re using for their 5/16” stem BBC valves could be made at the correct Hemi length if one really wanted to try it
Of course, for flow testing the length wouldn’t matter. Just buy the appropriate BBC valve and see how it works.
I had some old Top Alcohol style Hemi heads here a couple years ago. Some variation of the castings made by Stage V.
2.400 intake valves iirc........ and a normal looking non-tulip design.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Hemi "nail head" valves?
[Re: tubtar]
#2786916
06/18/20 06:35 PM
06/18/20 06:35 PM
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Joined: Jan 2003
Posts: 3,505 DFW
mr_340
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I tried a Manley BBC 2.25" intake valve in my MCH ported bracket heads. I lost flow from .100" on up with the BBC valve.
Lift Manley 12850 BBC MP Intake Valve 0.050 34.30 32.63 0.100 64.84 72.37 0.150 95.38 114.62 0.200 133.03 146.00 0.250 167.33 180.72 0.300 203.31 219.20 0.350 238.87 256.02 0.400 277.49 297.30 0.450 311.57 332.25 0.500 347.93 362.21 0.550 369.65 387.22 0.600 384.86 403.09 0.650 397.97 406.98 0.700 399.91 417.61 0.750 406.40 419.97 0.800 411.12 423.20 0.850 412.29 428.24
Floyd Lippencott IV
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Re: Hemi "nail head" valves?
[Re: mr_340]
#2786917
06/18/20 06:39 PM
06/18/20 06:39 PM
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Joined: Jan 2003
Posts: 14,506 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
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So. Burlington, Vt.
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Those are some noticeable losses in flow.
It seems as though if it were the hot ticket, you’d hear more about it.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: Hemi "nail head" valves?
[Re: mr_340]
#2786961
06/18/20 09:13 PM
06/18/20 09:13 PM
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Joined: May 2019
Posts: 713 Lake Villa Il
INTMD8
OP
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OP
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Lake Villa Il
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Great info mr_340
Thanks for the responses guys. Sounds like tulip is the way to go.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Hemi "nail head" valves?
[Re: INTMD8]
#2787612
06/21/20 12:04 AM
06/21/20 12:04 AM
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Joined: Jan 2003
Posts: 7,495 Minnesota
Hemi_Joel
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After Lofgren won the Royal purple Hemi challenge, he parted out the engine and I bought the heads. I put them on my red F.A.S.T. GTX. The intake valves are very flat on the backside. The late Glen Knowlton did all of the head work on them, he was a genius. They flowed around 420ish, but according to Glen the more important thing was the outstanding flow at lower valve lift numbers. The exhaust side flowed 315. I still have those heads laying around here somewhere.
Regarding that contest, according to Chuck the rules were very clear about displacement. When so many of the entries were found to be cheating on the displacement, or else they never read the rules, the organizers just let them all run anyway. Chuck was not happy about that. Then they made up some crap for the article about a misunderstanding of the rules.I'm so glad that Chuck won it because he was about the only one that was legal. You can probably reach him at KTRE. Knowlton's thunderheads racing engines.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
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Re: Hemi "nail head" valves?
[Re: Hemi_Joel]
#2787696
06/21/20 10:51 AM
06/21/20 10:51 AM
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Joined: Oct 2007
Posts: 4,209 New York
polyspheric
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master
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New York
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outstanding flow at lower valve lift numbers The tulip shape masks the port at low lift
Boffin Emeritus
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Re: Hemi "nail head" valves?
[Re: INTMD8]
#2788009
06/22/20 09:57 AM
06/22/20 09:57 AM
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Joined: Oct 2007
Posts: 4,209 New York
polyspheric
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master
Joined: Oct 2007
Posts: 4,209
New York
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Anything that significantly affects low lift flow also affect the best choice of LSA and overlap. Less flow needs more OL, narrower LSA. If it's faster with more low lift flow, maybe the cam was too small?
Boffin Emeritus
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Re: Hemi "nail head" valves?
[Re: polyspheric]
#2788039
06/22/20 11:25 AM
06/22/20 11:25 AM
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Joined: May 2019
Posts: 713 Lake Villa Il
INTMD8
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Hemi Joel, neat that you own those heads I could see how if it's faster with optimizing low lift flow maybe it just needed more cam. What are we talking when we say low lift? I'm planning on keeping lift low (sub .640) as I'm running stock rockers.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
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Re: Hemi "nail head" valves?
[Re: dthemi]
#2788042
06/22/20 11:50 AM
06/22/20 11:50 AM
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Joined: Mar 2018
Posts: 117 NW Indiana
powertrip
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member
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An asymmetrical valve job goes a long way to help the short radius problem too, and helps every hemi I've ever touched, I have started the turn for the short side right under the 45* seat angle in some applications, is this similar to what you do?
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