has anybody ever converted a 454 to a 525sc? is this possible, i think the 454 is the base of the 525.

chris

The first question is which 454 is currently in the boat. I'm not a mechanic, but what I understand is if it is a 365, 370, or 420 horsepower motor, it has all the good forged internals, good heads and valves, and can be built to a 525SC.

If it is a plain 454, plan to start from scratch.

sorry, didn´t mention: carburated 454 mag

I did it last winter. Gained 9-10mph on a twin engine 30' boat. I am very please with the result.

What blower did you use? I have heard Wieand 177 and 250 both called the 525sc blowers. Also did you lower you comp. ratio any? I have heard it's lower in the 525sc than any of the others mentioned.

I thought 525 were a different block and you couldent bore a 454 any more than 060 over and a 4.25 crank thats only a 496ci ? A blower doesent add ci

525sc is a 454 with 7.5 to 1 compression. It uses a weiand 177 blower, a 1050 dominator carb, and CMI etop headers. I have 2 and they are great motors.

OK they must be 525 hp not ci ,I was confussed . are they 4.281 bor and 4.00 stroke ?

The firt post reflecks 454 ci and then refers to 525 hp

HP525SC Specifications

Propshaft Horsepower: 490 (365 kw)
Displacement (Liter/CID): 7.4/454
Cylinders: V-8
Bore (in/mm): 4.25/108
Stroke (in/mm): 4.00/102
Compression Ratio: 7.5:1
Fuel Requirements: 92 Posted Octane (R+M)/2
Full Throttle RPM Range: 4800-5200
Ignition Type: Thunderbolt V
Alternator (amps/watts): 55/776
Length (in/mm): 47.625/1210
Width (in/mm): 32.75/832
Height (in/mm): 28/711
Weight (lbs/kg): 1470/667

They make 525 at the motor and 490 at the prop if running a bravo style drive.