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Re: How much power can a 426 Hemi make?
[Re: RUNCHARGER]
#338495
02/08/11 02:06 PM
02/08/11 02:06 PM
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Joined: Dec 2005
Posts: 4,252
State of retirement
52savoy
master
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master
Joined: Dec 2005
Posts: 4,252
State of retirement
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Quote:
Just for fun how about a 70's street machine formula. Stock 426 including pistons, heads etc. Now bolt on a set of headers, tunnel ram with twin 660's or 750 doubles and a 650 lift solid cam. Something like that ran deep into the 11's. Guys did it all the time.
Tuning the carbs on a tunnel, no different than a 440, setting timing on the Hemi, no different than a 440, setting the valves on a Hemi, no different than a 440. Oh wait, install new plugs on the Hemi, hey thats a lot better than burning your hands on those 440 headers at the track between rounds...
Sheldon
also..why is it fun beating another mopar? I always got off on beating up on chebbys. They were terrified of my Hemi. 
In 1979, my '68 roadrunner 426 street Hemi had stock bore and stroke(and cr) , stock heads with back cut valves with a Vanke intake, jetted stock AFB carbs, Crane R-290(.690 lift). It made between 625 and 650 hp. Shelby Starkey.. of Starkey and Christian super stock fame helped me set it up and was very surprised how fast it ran with used parts. I ran just as fast as their '67 WO car..10.60s. 
if I'm not mistaken all Racer Brown STX series cams were flat tappet. STR's were rollers. I ran a STX33 in the Hemi but wiped it. It was my fault because I wanted to drive the car in the winter(blizzard) of '78 
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Re: How much power can a 426 Hemi make?
[Re: 52savoy]
#338496
02/08/11 04:37 PM
02/08/11 04:37 PM
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Joined: Jan 2003
Posts: 2,763
Walton's Mountain, Pa
Steve1118
master
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master
Joined: Jan 2003
Posts: 2,763
Walton's Mountain, Pa
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Some of the STX cams were mushroom tappet. A pain, but they worked.
Jim, I think that the rule is just now being enforced, and the angle milling the head is what they do. I was told by a well known AH builder that they have "evolved", though, where the valve angle is not quite as critical.
Michael, the charge passing through the chamber on the overlap cycle has always been a problem at high rpm, simply due to the location of the valves opposing each other. They have seemed to alleviated that somewhat. The new rocker gear and related geometry has certainly helped, but it was not the complete answer.
All this work was at Barnett's shop in Georgia, back when we are all young and virile, Michael, and I don't recall your being there. We ran the Barnett's ex Pro Stock Arrow in IHRA T/S in the mid eighties. Even messed with nitrous in the early days, but that's another story.....
"Old age and treachery trumps youth and enthusiasm, every time!" East Central Director / Chrysler Power Magazine www.reasbeckracing.webs.com
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Re: How much power can a 426 Hemi make?
[Re: Pale_Roader]
#338498
02/08/11 08:04 PM
02/08/11 08:04 PM
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Joined: Dec 2006
Posts: 2,115
Byron, NY
W.I.N. Racing
top fuel
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top fuel
Joined: Dec 2006
Posts: 2,115
Byron, NY
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Here's a combo I ran in the late 80's early 90's
+070, Venolia pistons-13:1, stock steel rods, stock(valves,ports and combustion chambers)Heads, Weiand tunnel ram w/pr 660's, Crane R290, 2.125 27" long headers. In a 2950 lbs truck went 9.70's at 145 (5.13's and 33"rear tires)
Using a calculator come to 822 Hp at the flywheel.
All parts were available in the '70's
'01 P1500, Blown/Inj BAE,/Veney ,Bruno/CS2,Dana 60
'01 Dodge 3500 S Cummins Auto, Fresh air kit, 4" Exhaust,
'05 Dodge Magnum R/T - Too Much to list
'60 Willys CJ5
'01 International LPX - Project,DT466, Allison
'64 Plymouth Valiant, Inj 528 Hemi, 2spd
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Re: How much power can a 426 Hemi make?
[Re: RUNCHARGER]
#338499
02/09/11 10:46 AM
02/09/11 10:46 AM
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Joined: Jan 2005
Posts: 4,862
the frozen wastes...
Pale_Roader
OP
Swears too much
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OP
Swears too much
Joined: Jan 2005
Posts: 4,862
the frozen wastes...
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Quote:
Just for fun how about a 70's street machine formula. Stock 426 including pistons, heads etc. Now bolt on a set of headers, tunnel ram with twin 660's or 750 doubles and a 650 lift solid cam. Something like that ran deep into the 11's. Guys did it all the time.
Tuning the carbs on a tunnel, no different than a 440, setting timing on the Hemi, no different than a 440, setting the valves on a Hemi, no different than a 440. Oh wait, install new plugs on the Hemi, hey thats a lot better than burning your hands on those 440 headers at the track between rounds...
Sheldon
Sheldon, i dont want to scare you, but we do think alike sometimes...
I was thinking used hemi block, 440 crank, new (longer) rods and pistons, which would help with the bobweight issue, big lumpy solid cam. I'd want aluminum heads, if just for weight reduction reasons. Tunnel ram and 660's, good headers, stick... a nice old school powertrain (though hopefully with a 5 or 6 speed stick...) for an old-school looking hotrod. W'unt that be nice...
I should have bought a block and heads while i still had the money for those conversion heads i couldn't find...
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Re: How much power can a 426 Hemi make?
[Re: RUNCHARGER]
#338501
02/10/11 09:56 AM
02/10/11 09:56 AM
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Joined: Jan 2005
Posts: 4,862
the frozen wastes...
Pale_Roader
OP
Swears too much
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OP
Swears too much
Joined: Jan 2005
Posts: 4,862
the frozen wastes...
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I wont even start thinking about this until i can find some used hemi parts... block, alum heads, rockers. Everything else is either already sitting in my shop, or simple swap meet fare. The new stuff like rods and pistons, etc can be bought as i go along, as the budget allows. Just gotta get the hard parts first...
I keep thinking about a 383 in my Challenger, not sure why i like that idea so much more than a 440, or stroker, but i do. Or perhaps the modern route, but which way to go? Either way, it wont be done until there is a stock stroke 426 hemi sitting in front ov the stick in that car.
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Re: How much power can a 426 Hemi make?
[Re: mr_340]
#338503
02/10/11 02:52 PM
02/10/11 02:52 PM
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Joined: Jan 2003
Posts: 2,763
Walton's Mountain, Pa
Steve1118
master
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master
Joined: Jan 2003
Posts: 2,763
Walton's Mountain, Pa
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Jim, you are indeed correct. I know for a fact that straightening the valve angles was the hot setup for a while to alleviate that, however shady way it was being done. However, a well known AH builder told me recently that they've since gotten away from that, to some extent. The advancement in camshaft profiles seem to make sense.
To a ham and egg racer, like most of us are, though, it doesn't make much of a difference.
"Old age and treachery trumps youth and enthusiasm, every time!" East Central Director / Chrysler Power Magazine www.reasbeckracing.webs.com
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Re: How much power can a 426 Hemi make?
[Re: mr_340]
#338504
02/11/11 08:07 AM
02/11/11 08:07 AM
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Joined: Feb 2007
Posts: 970
Backwater, PA
bwdst6
Bob George Racing #1 Fan
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Bob George Racing #1 Fan
Joined: Feb 2007
Posts: 970
Backwater, PA
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Quote:
The cams have changed a lot since then. It seemed the old cams were 292-296 duration and 106 LSA and the newer cams are in the high 270-low 280 duration and wider LSAs like 110-112 (as far as I know). This gives a lot less overlap for the intake charge to blow out the exhaust. This might be several years old by now.
You calculate overlap by adding the intake duration and the exhaust duration, dividing that by two and then subtracting twice the lobe separation angle. For example, a comp cams 317SSR-8 grind solid roller, for a hemi has duration of 294, 285 with LSA of 108. This gives an overlap of 73.5 degrees.
Last edited by bwdst6; 02/11/11 09:00 AM.
This post is available in double vision where drunk.
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