7.4I magnum
Can anyone tell me the difference between the 7.4 and 7.4I magnum? Would the 7.4I magnum be enough to power a 32 Envision? I'm looking at this boat hard, but don't want to get it if it is underpowered from the get go.
thanx |
Originally Posted by bert4332
(Post 2239595)
Can anyone tell me the difference between the 7.4 and 7.4I magnum? Would the 7.4I magnum be enough to power a 32 Envision? I'm looking at this boat hard, but don't want to get it if it is underpowered from the get go.
thanx Assuming that they are EFI engines, the 7.4 is 330 HP, at a max RPM of 4600. The 454 Mag is 385 HP at a max RPM of 5000. The 454 Mag has all the good forged parts in it, while the 7.4 was not really intended to be a high performance engine. |
Like Duke said, the 454MAG is a much better package. Especially if you plan on any performance upgrades.
Darrell. |
Either way, if its a single in a 32 Envision, its way underpowered. That boat needs twins.
|
Depends on what yr the motor is.... if its a mark IV mid to late 80's then MERC labeled 330 hp oval port head 454's with the MAGNUM cuz it was pushin an alpha I 1.32 ratio.
A non mag 454 can be built for performance use. Your building all your HP at a relatively low RPM. 4800 to 5500. No problem for a pro built BBC. Would be nice if it did have the big rods, forged crank and forged pistions BUT Rectangular Port heads are not any better building torque/hp at boating RPM's I would look at how well the boat was maintained. HP is like Hamburger.. You can buy as much as you want. good luck with the purchase :cool-smiley-011: |
1 Attachment(s)
The boat is a 1995 Envision Intruder combo, see attached pic of motor.
|
As it says its a 454 mag and 385hp. Still way underpowered for a 32' boat. It would probably run 50mph on its best day.
|
Is there a formula to use to establish how much more HP an engine will need to get me to a certain speed? Mid 60s is where I want to be.
|
Originally Posted by bert4332
(Post 2241797)
Is there a formula to use to establish how much more HP an engine will need to get me to a certain speed? Mid 60s is where I want to be.
|
I've been looking for the formula for that insurance brokers use. I used to find easily and now I'm drawing a blank on how I searched for last time.
|
All times are GMT -5. The time now is 06:55 PM. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.