gripit

[QUOTE=Griff]The Merlin is not a "Dart" intake. Darts are made by Dart and Merlins are made by World products. The Dart is what came originally on your 420.


Why did the 420 HP originally come with the Dart Intake?

mrhorsepower1

John,
If your spinning the engine 5500-6000 @ WOT I would go with a Dart single plane oval port intake on your square port heads. Great way to increase velocity on mid range rpm engines and torque. I will port match the intake so the manifold is still oval and lines up with the roof of the heads. It wouldn't hurt to mill the heads a bit to get your compression up to 9.5:1-9.75:1 even 10.0:1 you are safe on 89 octane with 36-38 degrees timing.Hope this is of some help to you.

SB

iTrader: (1)

I did a wet dyno comparison on 502 w/ milder cam, same type low compression (just under 9:1), and the Canfield 310 heads w/cnc chambers. No other port work done.

Believe it or not the Brodix/HV 2000 single plane (pretty big intake) outmuscled the dual planes, even with a typical single plane torque dip. This was pretty much everywhere and dyno testes started at 2800rpm.



Did not test a Dart, although should have, but 3 intakes where enough for my pocket.

Was a weird one, didn't really believe it at first, but after tons of tests, the #'s fell where they where.

Just an experience by a lone guy (actually, two of us) that felt the need to dyno test for months on end. DOh !!!!

JohnSchiavarelli

Mrhourse,
The best I spin this is around 5500, maybe 5600.
I decided to keep the comp at 9.2:1 because I was worried about detonation.
Last summer I detonated a 496, so, did not want to go through that again.
I had the intake (current) matched to the heads already..

I am having some oil leaking issues on the front and back rails, so since I needed to fix this, I figured it might be a good time to replace the intake.

Not sure if it is really worth the extra coin. The motor makes aprox 620hp right now.. which is basically where I want to be.. might just fix the leak and forget it.

AIR TIME

I got a Q WHATS BETTER DART OR MERLIN OR BRODIX FOR A 510 WITH A NICKERSON 1050, RUNNING 5400TO 5800RPM RIGHT NOW WITHA DART 4150 WITH SPACER FOR THE 4500. This winter should I go to a 4500 intake and which one.? or stay with what I have.

mrhorsepower1

If your right where you want to be then save your money.

mrhorsepower1

What heads are you running? I have done a ton of R&D with 510 9.5:1 1X4 carbed legal B class offshore engines. We had about 8 boats running my power back then and won alot of races. With a highly modified Merlin Oval port head the Brodix intake made 15 more horsepower fully ported next to a fully ported Dart 4500 intake. We ran tricked out Dominator carbs which we built in house. Also have run Brasswell carbs with great results.

gripit

Mrhorsepower1,

Why do you think the 420 HP originally came with the Dart single plane Intake?

SB

iTrader: (1)

mrhorsepower1 - did you have an exhibit at PRI last Dec ?

JohnSchiavarelli

Any thoughts on what to use/do for the front and back rails leaking?
When I put the intake on last time, I did not use the rubber gaskets..Should I?? What sealant???
Also, should I put on some sort of PCV??? right now, I just have breathers on the valve covers..