FWK

A friend has a Baja 212 with a 454/310hp and the carb is going bad. The question is should he just replace the carb or while he is at it will he gain any performance by adding a intake. What intake if a change is recommended. Also, what carb the Edelbrock or a Holley and what size? He is adding a K&N flame arrestor no matter what he does. Thanks in advance, Forrest

mcollinstn

700 to 750 Holley Marine carb would be my choice, but he's fine with any marinized (U-tubes and fuel pump vent tap) 700-750 carb out there. He's currently got a Rochester on it.

What do you mean by going bad? A rebuild kit is under $20.

A 310horse motor will wake up a bit with an Edelbrock Performer intake and a cam swap, but he won't see a lot with just a carb and intake.

K&N won't help much either, but they look nice.

KCHOTBOAT

on my 7.4 with a procharger I got zero gain from adding a performer intake. It did look better than the stock intake.

Truckin

If you remove the intake manifold and look at the size of the ports you will see that the stock cast iron marine intake manifold has large oval ports and the cylinder heads have small round ports. This is a mismatch but doesn't seem to hurt anything. The Edelbrock Performer 2-0 is a manifold that has ports that match the small round port heads. Installing the Edelbrock Performer 2-0 manifold will match the head ports to the manifold ports but will give you an intake manifold with small ports and not increase your horsepower. Either stick with the stock marine intake manifold or install the large oval port Edelbrock Performer RPM 2-0 Q-Jet (and live with a port mismatch).
You can't do any better than a stock Quadrajet for your application, any carb rebuilder can rebuild a Quadrajet to work like new (for cheap).
Dennis Moore

1Boatnut

If your looking I have a Quadrajet and intake manifold in perfect condition that I changed from my 502...Bolt on and go!

FWK

It has the weber carb on it and it lets the fuel leak off into the manifold. This is why the question is being asked. I was shown some plugs under the carb that I was told always leak. Thank you Forrest

Sonic30ss

Dennis,
Just a thought here. Wouldn't the smaller correctly matched intake help with the low speed throttle response, and help to prevent any fuel from dropping out of atomization at those low speeds, do to the mixture hitting the obstruction caused by the head? While not hurting the top end since it has a small cam and low hp/ci? Might even help build torque down low do to increased port velocity.

Truckin

For low speed torque and fuel economy I think a correctly sized intake manifold would be better. At high speed I think he would be disappointed though. I have looked at the Big Block Edelbrock Performer intake many times and see a poor design. Don't get me wrong, I think they make great manifolds, but I think THIS PARTICULAR manifold is simply a large port intake manifold with the runners narrowed down where they meet the heads. It really isn't a low rpm style intake manifold but a high rpm intake manifold for a small port head.
Sincerely
Dennis Moore

Sonic30ss

Dennis ,
I've never seen this intake, but if it as you say necked down at the intake port, would'nt that be the best of both worlds?
Wouldn't you pick up velocity, as the mixture is forced through a smaller cross section, which is equall to the port size anyway. Theoreticly you aren't going to move any more air than the port will allow,. however if you can increase the velocity won't that help VE kind of like a tunnel ram? Not trying to doubt you, just find intake science, and air flow very interesting.
P.S. Have you seen any of Allen Lockeeds' work?

MACDAD260

If you want to change carbs, the stock manifold is made for a Rochester spreadbore carb. They just use an adapter plate for the stock squarebore Weber. A Holley is also a squarebore.