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.

Re: Two 427s
 

Aside from the heavy pistons & rings, what else do you think held it back?

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!

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!

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]

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.

Re: Two 427s
 

Here you go Mark:

http://i33.photobucket.com/albums/d7...ps3jlipnog.jpg

MJ horsepower with a Vintage carb, not a bad combination. [img]<<GRAEMLIN_URL>>/biggthumpup.gif[/img]

Re: Two 427s
 

Thanks Eric, thats some kind of carb!

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]

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>>/3gears.gif[/img]