Originally Posted by blue thunder (Post 2796523)

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

Originally Posted by OkieTunnel (Post 2796827)

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.

Originally Posted by chris-jack (Post 2796913)

Do you have closed fresh water cooling? It could be an place-issue with the SC.
Who did the conversion?
Or where did you buy the parts?
How much did you pay?
Did you chance the prop?

If i am happy with the hull, i should do a transformation with my next reconditioning. :drink:

Originally Posted by blue thunder (Post 2796919)

>Yes I run close cooling.
>My compression is 9.5:1. That is a better fit with this relatively small blower on a bbc
>I did the conversion.
>I bought these as takeoffs from a 525sc from a forum member
>$3300 for almost everything needed
> I went from 28p bravo 1 props to 32p b1s.

Originally Posted by jeff1000man (Post 2797137)

I have this entire blower set up as a freshwter take off if you are interested.

Intake, Blower, Belt, Pulleys. $1500 plus shipping. Don't know how many hours it had on it, but it turns over smooth, and feels like it should. I was going to do this also, but my interests have changed.

Originally Posted by blue thunder (Post 2797128)

If you go to boatfreaks.org look in the general discussion area, there are pics of the engines on stands. I am rebuilding them this winter and adding HR cams. Thread is Blue Thunder gets a face lift. I don't have any pics handly of the heat exchanger mounting. That was not part of my 525sc upgrade, these engines were already after market closed cooled. The heat exchangers sit right in front of the engines on a weldment frame bolted to the stringers.

BT :cool:

Originally Posted by chris-jack (Post 2797210)

Yes, it looks very good to me. but i cannot locate the thermostat housing!!