Motor upgrades

[MR nova @#25]

What kind of HP can I realistically expect, From a Ford 302 block with 351 heads? Weiand Warrior High rise dual plane intake manifold, topped off with a Edelbrock 1409 600CFM performance marine carb?

 

[Bt Doctur]

About 100 over stock I`d imagine

 

[achris]

What kind of HP can I realistically expect, From a Ford 302 block with 351 heads? Weiand Warrior High rise dual plane intake manifold, topped off with a Edelbrock 1409 600CFM performance marine carb?

What are you looking to do with the boat? More top end horsepower may not necessarily be the right thing unless you're planning on going real quick most of the time.

If you're going to be just cruising or pulling skiers/tubers around, then forget 'more horsepower' and look for more torque in the mid range...

Chris......

 

[Scott Danforth]

it helps to know what you are starting with. many Dorf 302 marine motors had GT 40 heads and ran the same marine cam as the 351. so in that case, about 230hp at the prop.

the added plenum volume helps a bit with torque.

or go with a stroker crank and get the cubes up to 347 and be running around 250hp at the prop.

at that point, maybe abandon the 302 and go with the 351 block

remember, its a boat, so with wet exhaust, your cam is limited. nothing wild or you suffer reversion.

 

[udoittwo]

Does it run great and you are just asking what it might have in HP? Is it something that you know nothing about but it's in a boat that you're interested in? Are the cam, crank and pistons stock? Was it originally a HiPo 302 or truck motor?
If you've run it and it runs well, it could be 50HP or more. An increase of 50HP is a lot for bolt on parts and a 600 carb is small for much more than 50HP. If it's slapped together and has a truck cam or something stock in there and stock pistons, it might be worse than stock. Mostly it's about matching the cam to the rest of the parts. To get more HP. everything has to be correctly mated or you might just have a gas hog with less power.You might be dumping in fuel that the motor can't handle.
I've bolted a high rise and 600 on a stock motor. There was very little noticeable performance gain but it did use more fuel. Which 351 heads are they? The big valve heads[I think the were "Cleveland" heads?] or the smaller 351 heads["Winsor" I think?] it's been a while. The smaller ones heads may give some increase but not a lot over the stock 302 heads. Don't know Ford heads but I'm sure you can google how to ID them as there should be some stamp on them to tell you what they are.

 

[MR nova @#25]

The boats a total rebuild that I started 6yrs ago, My work( Army) kept getting in the way. Now retired. I'm ready to get her in the water and start on my next boat. She came with pair of rusted out 302's. I purchased motors from 2 different sellers. one had 351 heads the other 302 heads. When the motors were sent out to get rebuilt, the guy matched the motors with 351 heads. I'm not looking for anything specific as far as performance. It's a Fishing boat that will spend most of its time on the Chesapeake If she tops out at 40Mph I'm cool if she tops out at 50 Mph im cool either way. I was just looking for info.

 

[Scott Danforth]

make sure they both have the same combustion mix....... from combustion chamber, thru intake manifold to cam and carburetor.

doubt you will get 50mph, stock 302 was probally 190hp range, so the most you should expect to see is about 250-260hp at the crank, or 220-230 range at the prop. adding plenum volume will increase mid-range