2barrel to a 4 barrel

[Grooter]

Ok I have a 1990 Donzi 210 dl with a 302 ford and looking to switch carbs.... Any input on this would be great

[Pat McPherson]

http://www.donzi.net/forums/showthread.php?70818-Replacement-marine-carb

[MOP]

My 91 16 had a 302 it came with a 350cfm 2b Holley, I bought a 4B manifold but ended not using it. I ended up putting a 500cfm Holley 2b on it that a buddy had. It ran about 2 mph faster, was a 20-30 minute swap.

[mattyboy]

fresh or salt?

[Grooter]

Fresh water ... Lake Ontario Sodus bay ny. Boat lacks top end performance..... Not interested in doing a full motor swap but that might end up happening... 35 mph isn't setting the world on fire.....

[mattyboy]

a 2 to 4 is not going to gain you a hole lot of gains in MPH but adding HP and loosing weight is usually the way to get there on the right prop

what rpm are you turning at 35 mph WOT what drive ratio?

[joseph m. hahnl]

Check the clearance under the motor cover. If adequate try to find a duel plane high rise manifold or use a thermal spacer. Edelbrock's are usually plug and play. in the event it needs jetting the meter rods make them easy to jet with out the need to take off, open the carb up, or replace the jets. a 600 to a 650 would be a good choice for a 302:kingme:

[tmdog]

Lets be realistic. Top speed 35 mph. That tells the whole story. You don't need a 4 b carb or a fancy intake, waste of money. Take a compression and leakdown test and more than likely indicate a worn out engine. Save your money for a rebuild. Better yet, more cubes, always better.

[MOP]

tmdog +1 35 says you have other things slowing you down, my 302 16 with the 500 cfm 2B would hit 49n in salt!

What is your WOT RPM, should be right at 5k, under that something is not right.

[joseph m. hahnl]

I chalk the 35 mph to being 210 DL we're not talking about a Classic .21 feet @ 2850 lbs with a 205 HP 302. 35 mph isn't to shabby. I think a duel plain high rise manifold and a 4 barrel is a good start and should bump it up to 235HP. It is also interchangeable with a 351W should he choose to upgrade to more CID's and again interchangeable with a longer duration camshaft for the 302. It is first and foremost the best bolt on mod for a gain of 30 HP out of the box and essential for any other modification.:kingme:


I highly doubt the engine is tired and needs a rebuild but a compression check is always a good choice to determine a problem with compression. Most top end problems can be attributed to faulty ignition components.