pelle

New engine dynoed on tuesday, and the results are;

445hp@4600rpm - 447hp@5500rpm,
544ft/lbs@3500rpm w/over 500ft/lbs
from 2500rpm-4500rpm,

Very pleased to the results, considering, that cam
is very small; crane´s 278/290 0.529"/0.525".
Dyno run was made w/BG 750dp on RPM Q-jet manifold,
32` total advance at 3750rpm w/24´T-Bolt ignition box.
Question is; should I run w/750, or 850 carb, as it seems
that engine might use some more cfm`s,as the power
stays flat for almost 1000 rpm`s?

750 or 850?

Payton

The 365hp 454 mag came stock with 750 cfm. I would say go with the 850

dyno

800 that comes on the 500 hp's works great I have them, 505 hp at 5700...Merlin heads are a big help!

fred

What bore and compression are you at........Fred

rmbuilder

Pelle,
Reference your dyno sheet. If your manifold vacuum is greater than 1.0 IN/HG between 4800-5500 RPM it's a good indicator of an induction restriction. Make sure it was measured between the carburetor and the back of the intake valve.
Bob

pelle

Spec`s are;

Blueprinted 454/330hp, now w/Eagle rotating kit, cast crank, I-beam rods, KB pistons, 9:1 CR, bore 4.280, Merlin 269cc heads w/2.30"&1.88"valves. Exhaust is Stainless Marine w/long SS risers. Rmbuilder, thank you for the tip

KH0302

RPM times cubic inches divided by 3456 = CFM. My motor is a 454 .030 over so it's 460 inches, it make its best power at 5000rpm, so 460 times 5000 = 2300000 divided by 3456 = 665.5 CFM at 100% volumetric efficiency. The 850 can't help you. My question is, is the carb a Qjet base like the RPM intake or is it square bore? If you have a square bor on an adapter on a Qjet intake, that's not good for volumetric efficiency.
Check out the Holley page link below...

http://www.holley.com/HiOctn/ProdLin...FMSC/FMSC.html

Griff

The 750 is plenty of carb. The power is more than likely flattening out because of the limitations of the cam.

PatriYacht

It sounds like you have a smooth running, strong engine. If you want more power a larger cam and a x pattern intake would be on my list. However, that will make your engine a little more tempermental.

pelle

Test run results

w/23"Mirage;58mph/5000rpm
w/24"Powertech 4-blade;61mph/4700rpm
w/26"Bravo One 4-blade;62,5mph/4700rpm
vs./stock 330 w/23"Mirage;53mph/4700rpm

So, it seems that it`s running right where it
should, with the power that it has?
445hp vs. 330hp? Test was run w/Garmin182GPS.
Suggestions to get 1-2mph more?

Pelle