Thread:

How big C.I. BBC

If you keep the stroke to no more then 4.375" and do the rest with bore this will enhance the longevity of the engine due to the fact the piston speed and windage issues will not require exotic parts to build longevity. IMO anything over this stroke in a BBC needs to be a drysump in a boat, especially if she is going to be run quite a bit.

Keep an eye on BoostPower's new proprietary CNC block. 800 cubes.

With standard bore spacing and a tall deck, 632 is about it. Lots of people say the long stroke/"bad" rod angle don't work but you sure see a lot of them in asphalt drag racing. I've never run over a 4.5" stroke, so I can't say from personal experience. Now a days, there are a lot of options on bore spacing, deck height and heads, the only real limit seems to be one's check book. Not hard to use up most of $100k on a new 5" BS based big inch motor. At the same time, when is it no longer a "BBC"!!
I've done a few 4.5" stroke motors and they work well. However, based on my experience for my use (lower $$, conventional head lake/bracket boat), I'm a big fan of a 565 (4.25 stroke x4.6" bore, preferably tall deck). Seems the best all around compromise for mostly off the shelf parts to run pretty good. Again, $$ and application defintely drive a lot of ones decision...

Oh snap, I misread the OP and made my reply too general. For a max RPM of 5800, I wouldn't hesitate to use a 4.5" stroke (598 with a 4.6" bore). Not to disagree with Chris but it's only another 1/16" per side more stroke and will generally be easier to build from off the shelf parts (cheaper). My current motor is a pump gas 580" deal in a flat. We spin it a bit higher (7200 or so) and use it similar to you. After a season of beating on it in a lake application, it still looks like new inside. Plumbed it for NOS this winter and plan on racing it a few time next season...