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#1
05-08-2015, 12:18 PM
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Re: Two 427s
Mark get up. It's Friday already, go hit the dyno. lol
John
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'58 Apache pick up restomodding with twin turbo 522 '78 Z28 4sp being restored '70 W30 convert TRIBUTE '70 CANADIAN Nova SS396 L78 Pro Street '69 CANADIAN Nova SS 396/350 hp '67 CANADIAN Nova SS 427 10 sec. driver '66 CANADIAN Nova SS Race Car '69 FIREBIRD Tubbed Racecar '31 ALL STEEL Chevy P.U. GONE (EX-WIFES NOW) '61 CANADIAN Pontiac Bubble top 409+/4sp (SOLD) '78 Z28 32,000 survivor, Og Yellow paint, AC. (SOLD) 
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#2
05-08-2015, 06:16 AM
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Re: Two 427s
Just run a step test or tweak the vapor pressure a little! LOL.
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Remember the days of carburetors,chrome,and leaded gasoline? 1969 Nova SS L78 4-speed
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#3
05-09-2015, 12:51 AM
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Re: Two 427s
John, engine number 2 made 608 HP @ 6500 RPM, I made some mistakes on this build, and would like to try it again some time.
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#4
05-09-2015, 02:19 PM
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Re: Two 427s
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Vortecpro</div><div class="ubbcode-body">
John, engine number 2 made 608 HP @ 6500 RPM, I made some mistakes on this build, and would like to try it again some time. </div></div> Ya Mark, your right. It's down a tad from where I thought it would be, 620/630 range, RPM is right though lol. We have found that in some cases, the light weight "rotating assembly" can actually HURT a cars performance. More in these heavy streetcar type of deals. We believe the especially on the street when you not fully into it, the heavy rotating help on shift recovery??? Inertia???? i don't know for sure, but found on cars that are 3700+ this seems to happen, yet track ET's seems consistent within less then a tenth? Funny, guys are looking at motor 2, but overlooking the fact that a stock style L72 in motor 1 made 570??????? I see a few places on that build as we know and you could easily be 630Hp, just not sure exactly how the motor went together. Mark, good work as always.
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'58 Apache pick up restomodding with twin turbo 522 '78 Z28 4sp being restored '70 W30 convert TRIBUTE '70 CANADIAN Nova SS396 L78 Pro Street '69 CANADIAN Nova SS 396/350 hp '67 CANADIAN Nova SS 427 10 sec. driver '66 CANADIAN Nova SS Race Car '69 FIREBIRD Tubbed Racecar '31 ALL STEEL Chevy P.U. GONE (EX-WIFES NOW) '61 CANADIAN Pontiac Bubble top 409+/4sp (SOLD) '78 Z28 32,000 survivor, Og Yellow paint, AC. (SOLD)
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#5
05-09-2015, 01:49 AM
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Re: Two 427s
Aside from the heavy pistons & rings, what else do you think held it back?
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#6
05-09-2015, 02:16 AM
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Re: Two 427s
Interesting question Eric. I've been told you don't usually see gains from lightweight cranks, rods and pistons on the dyno. They do help acceleration, but are just hard to measure on the dyno. My gut feeling is there should be some freed up hp, but I don't have much experience with dynos.
My Dad's 302 sure did well with a good set of rings- so i trust there could be a couple percent gain right there. I look forward to the evaluations. Thanks for sharing!
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Paul III 
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#7
05-09-2015, 02:43 AM
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Re: Two 427s
I have seen nothing on the Dyno with light parts. But they do help in the car. They rev faster between gear changes. I think your numbers sound right. Both Very strong engines. Great job on both!
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#8
08-06-2015, 04:36 PM
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Re: Two 427s
Here you go Mark:
 MJ horsepower with a Vintage carb, not a bad combination. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]
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#10
08-07-2015, 03:37 AM
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Re: Two 427s
Thanks Mark. [img]<<GRAEMLIN_URL>>/beers.gif[/img]
I heard a little hiccup at the hit to WOT, might need a little heavier secondary spring. Test, tweak, test again, tweak some more...all in a days work. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]
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