Big block mercruiser 454

[Brow72]

I have a 1990 24ft cuddy cab with a mercruiser 454 with a bravo one outdrive. When I got the boat, the previous owner has put a in line electric fuel pump on it.
Questions:
1- is that better or worse than the original manual fuel pump?
2- what is the ideal fuel pressure for most power and performance? ( I’m not sure what this electric one is making)
3- what should the max speed be and at what rpm’s? ( I just feel the boat should be faster for having a big block in it )
4- any ideas of how to get more power and performance out of it without breaking the bank..
thanks for any and all help

 

[tpenfield]

Carbureted 454??? . Do you know if it is the regular 7.4/454 or the 454 ‘Magnum’ version.

the regular 454 is about 330 hp in that year, the Magnum was 365 hp.

fuel pump should be fine either type. The carb will take what it needs

my 24 foot cuddy with 454/Bravo 1 would do 48 mph ( 24 degree deep V) at about 4400 rpm. The rpm is rated 4600 max (5000 for the Magnum). It had a 21” pitch prop. The boat had a dry weight of 4700 lbs.

the engines are designed to have good low-end torque and a decent top end. The regular 454 has the oval port heads and the Magnum has the rectangular port heads. Thru-hull exhaust might get you a bit more top end. Otherwise it can get pricey.

what brand/model boat is it? What is your speed and rpm

 

[Bondo]

Ayuh,.... Welcome Aboard,..... Electric, or mechanical don't matter,....
Though, an electric pump must be wired through an oil pressure switch, to kill it if the motor ain't runnin',....

Carbs need 4 to 6 psi,.....

You should prop it for a max rpms of 'bout 4800 rpms,.... the speed will be whatever it is,.....

A compression test will reveal the over all general health of the motor,.....