Hey guys, I’d like your advice on a cam and Carb for a project. I have just purchased a used Innovation Marine Donovan 11.100 Aluminum engine built for the Navy. Crower Billet 5.1” Crank & Crower Billet Rods. Dart 360’s ported out to something even larger. Hydraulic Roller lifters. Pretty nice stuff. Originally built at 647 cid. Bores will clean up and yield 650cid. Coated Pistons. Coated bearings.
Compression was 8:1 and we will mill heads for a 9:1 CR. It will run through a Huber 72C Borg Warner.
For good longevity & reliability with a 5.1” stroke, what max rpm should we use? Is 5000 too high? What cam specs would you guys suggest for that RPM? Single 950 Holley, or Dominator Carb?? Thinking Keith Eikert Exhausts or DanaMarine. How much horsepower?? Would 750 be easy at 5000??
Thanks, Mark

Man,do they have anymore of those things laying around ? With that stroke it otta put out 1000 lt/lbs of torque at 5000 rpm.

Well, the Navy in all their infinite wisdom never sells them complete or assembled. They tear them apart and throw them out in a field for a few months to let them rust. Then they auction them off in “parts form” Sometimes the steel billet main bearing caps are missing! Seems the Navy doesn’t want any liability for an engine not running… and they also don’t want to compete with the “private sector”. So after looking and asking for three years, I finally found one that is complete enough to rebuild. I would guess the torque to be in the low 800’s.
How high can you rev a 5.1 inch stroke?? -Mark