Go Back   The Supercar Registry > General Discussion > Technical & Restoration


Reply
 
Thread Tools Display Modes
  #21  
Old 05-08-2015, 11:51 PM
Vortecpro Vortecpro is offline
Yenko Contributing Member
 
Join Date: Apr 2011
Location: Thousand Oaks Ca/Colorado Springs Colorado
Posts: 168
Thanks: 5
Thanked 54 Times in 34 Posts
Default 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.
Reply With Quote
  #22  
Old 05-09-2015, 12:49 AM
VintageMusclecar's Avatar
VintageMusclecar VintageMusclecar is offline
Senior Member
 
Join Date: Jul 2003
Posts: 3,366
Thanks: 158
Thanked 161 Times in 46 Posts
Default Re: Two 427s

Aside from the heavy pistons & rings, what else do you think held it back?
Reply With Quote
  #23  
Old 05-09-2015, 01:16 AM
PxTx's Avatar
PxTx PxTx is offline
Yenko Contributing Member
 
Join Date: May 2001
Location: Glenside, PA 19038
Posts: 2,632
Thanks: 30
Thanked 52 Times in 37 Posts
Default 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!
__________________
Paul III
Reply With Quote
  #24  
Old 05-09-2015, 01:43 AM
KenMaisano's Avatar
KenMaisano KenMaisano is offline
Senior Member
 
Join Date: Jun 2013
Location: So .Cal.
Posts: 446
Thanks: 0
Thanked 165 Times in 81 Posts
Default 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!
Reply With Quote
  #25  
Old 05-09-2015, 05:55 AM
RST's Avatar
RST RST is offline
Yenko Contributing Member
 
Join Date: Jan 2014
Posts: 596
Thanks: 119
Thanked 102 Times in 47 Posts
Default Re: Two 427s

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KenMaisano</div><div class="ubbcode-body">Engine#2

Well the 870 Square port has two points more compression could add about 30HP.
The 781 Oval port has 20 degrees more duration could add about 30HP. But the oil pan is +10HP
If the 781 larger valves were machined correct. about 1.900 Bowl area and chambers deshrouded.
The Oval port Engine should take the win by about 30+ HP.

I built a 049 Oval port 454 8.5to1 compression Q jet Super Stock engine in the early 1990s and it make 660HP. The Ovals can really work, these were 2.08 1.7 255ccs.

</div></div>

Looks like you called it Kenny, although you were off by 3 HP [img]<<GRAEMLIN_URL>>/smile.gif[/img]
__________________
1968 1/2 Cougar 428 R Code, Cobra Jet, 4 SPD, Red Interior in restoration at MASCAR to be unveiled by Kevin Marti at the MCACN 2020

1970 Top Secret Very Special Muscle Car in restoration by MASCAR to be unveiled at MCACN 2020

Reply With Quote
  #26  
Old 05-09-2015, 01:19 PM
EZ Nova EZ Nova is offline
Senior Member
 
Join Date: Mar 2004
Location: Ontario, Canada
Posts: 982
Thanks: 26
Thanked 211 Times in 126 Posts
Default 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 &quot;rotating assembly&quot; 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.
__________________
'58 Apache pick up
'78 Z28 4sp being restored
'70 W30 convert TRIBUTE
'78 Z28 32,000 survivor, Og Yellow paint, AC.
'69 CANADIAN Nova SS 396/350 hp
'67 CANADIAN Nova SS 427 10 sec. driver
'66 CANADIAN Nova SS Race Car
'61 CANADIAN Pontiac Bubble top 409+/4sp (SOLD)
'31 ALL STEEL Chevy P.U. GONE (EX-WIFES NOW)
Reply With Quote
  #27  
Old 08-06-2015, 03:36 PM
VintageMusclecar's Avatar
VintageMusclecar VintageMusclecar is offline
Senior Member
 
Join Date: Jul 2003
Posts: 3,366
Thanks: 158
Thanked 161 Times in 46 Posts
Default Re: Two 427s

Here you go Mark:



MJ horsepower with a Vintage carb, not a bad combination. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]
Reply With Quote
  #28  
Old 08-07-2015, 02:21 AM
Vortecpro Vortecpro is offline
Yenko Contributing Member
 
Join Date: Apr 2011
Location: Thousand Oaks Ca/Colorado Springs Colorado
Posts: 168
Thanks: 5
Thanked 54 Times in 34 Posts
Default Re: Two 427s

Thanks Eric, thats some kind of carb!
Reply With Quote
  #29  
Old 08-07-2015, 02:37 AM
VintageMusclecar's Avatar
VintageMusclecar VintageMusclecar is offline
Senior Member
 
Join Date: Jul 2003
Posts: 3,366
Thanks: 158
Thanked 161 Times in 46 Posts
Default 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]
Reply With Quote
  #30  
Old 08-11-2015, 03:19 AM
firstgenaddict's Avatar
firstgenaddict firstgenaddict is offline
Yenko Contributing Member
 
Join Date: Jul 2001
Location: Greenville, South Carolina
Posts: 5,596
Thanks: 161
Thanked 942 Times in 457 Posts
Default Re: Two 427s

`wdj<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: VintageMusclecar</div><div class="ubbcode-body">

Like I told him over on the Chevelle forum--if I owned my own dyno, you'd likely never get me away from the damned thing. </div></div>
I can't dream up a better circumstance... well if you want to throw in even a 1/4 scale Wind tunnel I'd take that as well. [img]<<GRAEMLIN_URL>>/[/img]
__________________
~JAG~
NCRS#65120
68 GTO HO 4 spd Alpine Blue /Parchment 2 owner car
#21783 71 Corvette LT1 45k miles Orig paint - Brandshatch Green - National Top Flight - last known 71 LT1 built.
71 Corvette LT1 42k miles Original paint - Black - black leather - only black LT1 known to exist.
NUMEROUS Lemans blue Camaros,
Monza Red and Daytona Yellow Corvettes
& a Chevelle or two...
Survivors, restored cars, &amp; other photos
https://picasaweb.google.com/lh/myphotos
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:00 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.

O Garage vBulletin Plugins by Drive Thru Online, Inc.