383 with 2bl carb
#42
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I know this, because of I have done this live more than a dozen times. IE: People that tell me secondaries don't open until a higher rpm. I disconnect the secondaries and the boat won't plane. Yup, even 20ft and under boats with very little weight.
The primaries are just to small.
Also, as i referred to...the secondaries do open at planing rpm. Again, if they don't, the boat will not plane.
The load - boat/gear/fuel/etc,etc - is responsible for how much hp you need for X mph. HP used determines how much fuel you use.
#43
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Location: Spicewood, Texas USA
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For what it's worth, Volvo sells a 5.7 rated at 250HP. It has a 4bbl intake with an adapter and 2bbl holley carb. That same engine with TBI on the same intake is rated at 320 HP. I have converted several from the 2bbl carb to a 4bbl carb. They all picked up a noticeable amount of performance and every owner said the economy improved.
The reason Volvo and Merc offer these packages is strictly price point, not performance or economy. Basically they are detuning the 350 Mag, because the engines are identical other than the fuel system.
The reason Volvo and Merc offer these packages is strictly price point, not performance or economy. Basically they are detuning the 350 Mag, because the engines are identical other than the fuel system.
Last edited by bobl; 04-08-2014 at 01:11 PM.
#44
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For what it's worth, Volvo sells a 5.7 rated at 250HP. It has a 4bbl intake with an adapter and 2bbl holley carb. That same engine with TBI on the same intake is rated at 320 HP. I have converted several from the 2bbl carb to a 4bbl carb. They all picked up a noticeable amount of performance and every owner said the economy improved.
The reason Volvo and Merc offer these packages is strictly price point, not performance or economy. Basically they are detuning the 350 Mag, because the engines are identical other than the fuel system.
The reason Volvo and Merc offer these packages is strictly price point, not performance or economy. Basically they are detuning the 350 Mag, because the engines are identical other than the fuel system.
The Volvo package was good...to up the HP over the Merc set-up.
It used a bigger 2bbl than merc does, but more importantly, as you said, it used an adapter on a 4bbl intake. The adapter and intake both increase airflow a good amt.
I've done a bunch of 2bbl to 4bbl too.........and it's a crazy good upgrade.
The 2bbl stuff, just like when Chevy and other companies did it on V8's, is exactly what you said ....was strictly price point.
Want more power ? Give us extra money.
#46
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This is the engine I am planning on putting the 2 bbl on. I am going to have them put a smaller cam in it for smoother idle and I really don't need all that power. So its not like I am putting a 10k motor in the boat and slapping on the 2 bbl. This is just a budget build using take off parts from my 305.
http://pmcmachine.com/index.php?main...arine&x=58&y=1
Chris
http://pmcmachine.com/index.php?main...arine&x=58&y=1
Chris
#47
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This is the engine I am planning on putting the 2 bbl on. I am going to have them put a smaller cam in it for smoother idle and I really don't need all that power. So its not like I am putting a 10k motor in the boat and slapping on the 2 bbl. This is just a budget build using take off parts from my 305.
http://pmcmachine.com/index.php?main...arine&x=58&y=1
Chris
http://pmcmachine.com/index.php?main...arine&x=58&y=1
Chris
Last edited by phragle; 04-08-2014 at 07:37 PM.
#48
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Phragle, lay it out brother, tell us how you really feel. LOL.
Sounds like a pass to this company, Time to find another.
Sounds like a pass to this company, Time to find another.
#50
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Don't let us stop you.