557 vs big cubic inches
 

I realize that 557 ci isn't a small displacement, but compared to what is being built out there -- 705 etc--- it is on the modest side.
So why is it that the bigger builders like merc, sterling and others have been using the 557 platform for so many of the big hp builds?
is it the fact that they can spin them faster to make the hp and still stay together? i can see this as a major plus with the cats...
If someone wanted to build some 1100 - 1200 hp engines for a 12,000lb boat what would be the best cubes to start with?
This would be a pleasure V/ poker runner, top speed would be great around 100mph, cruise at around 65 mph.

Any input is welcome.

Thanks, Dave

I could be mistaken, but I think 557 is about as big as you want to go with standard 9.8 deck height.

1100+ hp gets difficult on pump gas on a standard 572. I imagine 632's with 1671 or whipple 5.0's should get the job done reliably.

565 is about the best combination I'm told by 3 of the big name race engine builders(sonny's, reher/morrison, shafroff) using a short deck...the real long stroge big cube engines are hard on cranks...even the high $$$$ ones

i've already got the tall decks -- can still make a smaller ci with tall deck -- and utilize longer rods to help rod geometry.

So it is more of the tall deck vs standard deck issue is what i'm hearing?

Most of the top builders use the tall deck 10.200 for the 557ci.

Delsol, what were your motors originally? BTW, beautiful boat! I remember seeing it at loto some time back.

Bore, Stroke, Rod length for that combination?

4.5inch bore , 4.375 stroke, 6.535 rod length, tall deck block

+1 you will want to start with one of these!

Attachment 492836

Thank You