Intake and Carb. upgrade?

[YmeHP]

Hello, i'm looking to update the intake and carb. on my stock 89' SBC OMC Cobra 350. What is my best bang for the buck; Edelbrock, Weiand, or Holley intake? Would you recommend the Edelbrock or Holley 600 cfm carb?

 

[danond]

Re: Intake and Carb. upgrade?

Why are you doing this?

 

[YmeHP]

Re: Intake and Carb. upgrade?

Why are you doing this?

Really, just to update the stock carb. rather than rebuilding and just had the thought of updating the intake just because I guess. I only run the boat in fresh water and will I have any noticeable gains in either HP or fuel economy?

 

[Mkos1980]

Re: Intake and Carb. upgrade?

If just freshwater, I'd run a Edelbrock RPM intake for 87-95 heads and a Edelbrock 600 Carb. The RPM intake is the same height and RPM range as the Cast iron Bowtie intake that the MerCruiser Magnums ran. Regular performer is not a very good improvment over what you have and in the Marine performance handbook I got its noted that the Performer should just be used on 305's

 

[Mkos1980]

Re: Intake and Carb. upgrade?

You are going to spend a lot of money and work for very little gain. My bet, less than 2 MPH on the top end.

Gotta start somewhere. Yet people will drop 3-5K more on motor upgrades from like a 250HP Merc to the 350 Mag for what? A few more MPH?

 

[danond]

Re: Intake and Carb. upgrade?

YmeHP: you're going to spend big $ and gain next to nothing. Rebuild the original carb, your checkbook will thank you!

Mkos1980: You're invalidating your own argument, as I agree with you. Changing the engine (or adding horsepower 50-100 HP at a time) is really the best way to get noticeable performance gains in a boat, not piecing things together on your factory engine.

Increasing performance in a boat should be a FAQ item. This has been rehashed so many times it's crazy. A boat is not a car. You simply will not get anywhere near the same performance gains in a boat that you do part-for-part in a car. Physics says so.

 

[John_S]

Re: Intake and Carb. upgrade?

If the 2brl carb is beyond simple rebuild (shafts worn, warped body, etc) the intake/4brl will be much more cost effective. The new 2brl carbs can be expensive.

Gain is about 30hp, and will pick-up a few wot mphs.

If it is worth it or not, is up to the individual boater.

 

[danond]

Re: Intake and Carb. upgrade?

A new 500cfm Holley 2bbl marine is $375, the most I could find on eBay, anyway. There were Rochesters and other brands for less. Significantly less than a new intake and 4 barrel marine carb setup, unless you find one used, which puts you back in the same boat. Pun intended.

Regardless, any 4bbl, even a mechanical one like an Edelbrock, won't do much for the engine until it reaches WOT or close to it, so keep in mind that this is the only place you'll see gains, and they'll be minimal. An engine swap or a stroker kit is a better choice if you want "seat of the pants" type gains. Otherwise, the 500cfm Holley marine is a great carb and is tune-able to a fault.