My brother is putting together a pair of 572 cui BBCs for his 30’ Scarab. The long block specs are:
Cam ≈.632 lift, 112 LSA, Roller (edit:I/E @.050 256/264)
Planned Max RPM 5800
1050 Dominator, (2 circuit)
WP Merlin Marine single plane intake
CMI exhaust headers
Planned Compression Ratio 9.25:1 (based on stock Gen V 118cc heads) (He wants to run on Premium from the pumps.)
30’ Scarab, twin TRS outdrives
He runs in the James River, Hopewell, VA so he is in brackish water and but will likely run down to salt water in the Chesapeake Bay occasionally. The boat needs to stay family friendly. So considering the corrosion issue and all the performance tradeoffs, offer your opinions on the following:
Should he run Cast Iron or Aluminum heads?
What runner size?
What Valve size?
What brand has the best head for this application?
There is a budget for the project, but his wife is not looking too close.
Other cool engine info:
Dart Big M block
Diamond custom pistons, ceramic coated
If ya want/need more info, let me know and I will ask my brother.