sbc 421 dyno results
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sbc 421 dyno results
Finally got my sbc 421 together and put it on the dyno
Here are the specs:
4.155 bore x 3.875 stroke, 421sbc nitrous motor
12-1 compression, 5.6 dome
Jones cam (lift.699 int, .659 ext) (dur @seat 316int 320ext) (LS112)
AFR245 unported heads with LGM shaft mounts (1.7 int, 1.65 ext rockers)
Edelbrock 2970 ported
Mark Whitner 1050 dominator
Used 1 3/4 dyno headers
With 110 octane fuel made 586 TQ @ 5200 and 686 HP @ 7200 with 34 degrees timing
https://ibb.co/nBMmpc
https://ibb.co/m2Kgpc
With 94 octane pump gas made 567 TQ @ 5400 and 657 HP @ 6500 with 30 degree timing
https://ibb.co/e3A1Nx
Overall really happy!
https://ibb.co/csTP9c
https://ibb.co/eQPLhx
Can't wait to spray a 300hp shot to the engine
I have to install my powerglide 1st before I spray, no way my th350 I have now will hold the power
Here are the specs:
4.155 bore x 3.875 stroke, 421sbc nitrous motor
12-1 compression, 5.6 dome
Jones cam (lift.699 int, .659 ext) (dur @seat 316int 320ext) (LS112)
AFR245 unported heads with LGM shaft mounts (1.7 int, 1.65 ext rockers)
Edelbrock 2970 ported
Mark Whitner 1050 dominator
Used 1 3/4 dyno headers
With 110 octane fuel made 586 TQ @ 5200 and 686 HP @ 7200 with 34 degrees timing
https://ibb.co/nBMmpc
https://ibb.co/m2Kgpc
With 94 octane pump gas made 567 TQ @ 5400 and 657 HP @ 6500 with 30 degree timing
https://ibb.co/e3A1Nx
Overall really happy!
https://ibb.co/csTP9c
https://ibb.co/eQPLhx
Can't wait to spray a 300hp shot to the engine
I have to install my powerglide 1st before I spray, no way my th350 I have now will hold the power
Re: sbc 421 dyno results
Looks like a legitimate number. Should be fun. Those heads are fast and respond well to increased cross section. And short turn work.
Mark builds some great carbs
Mark builds some great carbs
Re: sbc 421 dyno results
why 112lsa?
also why such a small header?
My 420 picked up 1.5mph by changing from a 1 3/4" to a 1 7/8" (per pipemax)
also why such a small header?
My 420 picked up 1.5mph by changing from a 1 3/4" to a 1 7/8" (per pipemax)
67 camaro
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
Re: sbc 421 dyno results
Probably this.
Can't wait to spray a 300hp shot to the engine
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: sbc 421 dyno results
They were dyno headers, likely his car headers wouldn't fit on the dyno hopefully he will enlighten us.
Re: sbc 421 dyno results
Not the headers. The LSA.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Re: sbc 421 dyno results
BTW, that 112 LSA is misleading. The distance from max lift on the exhaust lobe, to max lift on the intake lobe is 108 degrees.
Mike Jones
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Jones Cam Designs
Denver, NC
jonescams@bellsouth.net
http://www.jonescams.com
Jones Cam Designs' HotPass Vendors Forum: viewforum.php?f=44
(704)489-2449
Re: sbc 421 dyno results
Yes, the dyno headers were 1 3/4. That's the biggest he had.
I have 1 7/8 on my car. Probably need to go to a step header when I spray a bigger shot
Yes, this engine is made for nitrous.
I have 1 7/8 on my car. Probably need to go to a step header when I spray a bigger shot
Yes, this engine is made for nitrous.
Re: sbc 421 dyno results
Good question, the consensus was always bigger but others question that due to the increase in cylinder pressure. I had a long conversation with Calvin about that, maybe he will chime in and share his thoughts.
There is a lot of thought out there on nitrous engines, cams, pressure differential across the valves but I don't know many that have done back to back testing with the different theory's.
The one nitrous engine I dynoed was an 11.1 357 SBC that made 530 on motor, 710 on a 150 shot and 820 on a 300 shot with an 1 3/4 dyno header because that's what he had.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: sbc 421 dyno results
I built a 304CI 2V Ford Mod Motor that runs 8.80's @ 155 on a 300 shot @ 3150 lbs and we had a set of off the shelf Edelbrock Victor series headers 1 5/8 to 1 3/4 stepped with a Merge Collector and I thought once we put a set of 1 7/8's headers on it we would gain alot but it only picked up marginal amount.
Funny stuff happens sometimes, you never know until you test
Funny stuff happens sometimes, you never know until you test
Re: sbc 421 dyno results
Just curious, what makes a 108 cam a 112 on paper?
The little bit of track testing I did back in the day with a wide lsa "nitrous cam" advertised of course never seemed to make a noticeable difference, if anything it hurt 60' and et on straight motor.
One of the fastest guys back then, mid 2000 ran a 421 SBC, Chevy II on drag radials with a moderate sized herbert cam on a 106 lsa, the car would run 5.50's on a 78 pill and a 5.30 on a 102 pill... really made me question the "nitrous cam" theory.
His engine dynoed 675 horse.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
Re: sbc 421 dyno results
I hope when Mike explains this, he recalls what a CJ it turned into a few years back when the discussion of how LSA/LCA should be specified became heated...
Felix, qui potuit rerum cognscere causas.
Happy is he who can discover the cause of things.
Happy is he who can discover the cause of things.
Re: sbc 421 dyno results
Yeah, I don't want to see that, I am guessing it has to do with asymmetric verses symmetric lobes...I hope thats the correct term but probably over simplified.
Maybe best to avoid it all together.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: sbc 421 dyno results
The lift peak does not necessarily fall at the central point between valve open and close.
So it may be 108 between lift peaks and 112 between the open/close center points.
OR , this cam is made from an advanced rubberized billet that self alters its advertised and dynamic LSA's, possibly marketed as the "lift n' twist" billet! ah now I've done it!!
So it may be 108 between lift peaks and 112 between the open/close center points.
OR , this cam is made from an advanced rubberized billet that self alters its advertised and dynamic LSA's, possibly marketed as the "lift n' twist" billet! ah now I've done it!!
Craig.