I am sill in the planning stage but after many months of going back and forth on what engine components, blower, and induction system I am getting close. My goal is two have the best running, idling, docking manners, reliability and still the highest MPH. I need to represent my marina properly. The only thing I will leave to chance for now is the drive. It is an IMCO extreme -3 setup. I expect if I get to top speed easily the lower may last 50 hours. Then I will replace the upper and lower with the new IMCO SCX. But for now I will dedicate my effort to the engine. The highest top speed I have heard of is 108 MPH.
I will update this as soon as I make the final decision on parts. Then the build and fun will begin.

throw a whipple on there!

Get a good look..ha ha ha Just busting your balls. Holden said he had 800hp in it to get to 108. But remember this boat is basically stripped down and light. With what you have planned you shouldn't have a problem taking the title.

I'm a Procharger Dealer.. So to let a little out of the bag it will have a M-5 on it
I also want to build something cost effective, to do a Whipple 4 Liter EFI it would cost another 5K. Not worth that little bit of efficiency. I will make very close to the same power but may loose some MPG over the Whipple due to the Whipple taking less HP to make the same boost (the Whipple being a little more efficient). I hope not to upset the Whipple people out there but I feel this is a fact. I may need to throw another # of boost at the motor to make the same HP as the Whipple.
Looks like I let the EFI out of the bag also. So far M-5 Procharger with Accel EFI. I am on the fence with the block and components.But am very close to nailing that down. I am debating solid or hyd right now. My 509 is solid and I love it, it works for me my guys can adj the valves a few times in the summer and in the winter we can replace the lifters. But thinking from a cost standpoint the Hyd lifters would be the way to go as far as maintenance (yearly lifter changes), and I could build some more cubes. So in brief that is my issue.. And I am very close to an answer that will work for my project. I am thinking from a standpoint if I see a customer out. I can tell them I tear it down every 250-300 hours to be safe or do I tell them I have to adjust the valves a few times a summer and replace the lifters yearly? Constant maintenance to some people looks like you made bad choices all though we know better.

It sounds like a sweet project you have planned. I cant wait to see a 120mph speedo pegged

All you guys are planning bigger and faster and more powerful, and here I am planning to build mine down a bit.

Keep us updated for sure Don

When I Had Mine It Ran 104///106 Any Day Of The Week,,,,,Full Cabin,,,

Let her rip Don!

II finally made up my mind, I was struggling between a smaller CI motor and some RPM's and a Large motor and not so many RPM's the issue was in maintenance which really is not all that much of an issue (solid Vs Hyd cam), and which size prop I could use. I didn't want to go to 1.25 gears and didn't want to swing a monster prop on a single engine smaller boat. I wanted the boat to have more of an influence of where we were going than the prop..
So I decided to settle in the middle and order a Merlin III tall deck. It will be a 572ci with a 4.375 stroke and 4.560 bore. I expect to spin it around 6000-6100. I will boost and cam for that. That gives me a few hundred RPM's of safety margin for a pleasure boat,
That's all for now. 572, M-5 Procharger, Accel DFI. Next is to pick the heads.. I have been going around for a few months on everything so far, so a few more weeks wont hurt. Leaning toward the AFR 357's.

Procharger is building my system. They do much more R&D on the auto side. They have a new design they just came up with and tested that they are going to put in my M-5SC. They make there impellers and in fact there systems all in house. They are going to apply the new technology to my M-5 impeller. It will come on sooner, not surge, and make more HP for the same boost due to a more efficient design. They scheduled to start building my system this Thursday. I ordered a pulley to make 10psi @ 6200 RPMs. That should get me started. Procharger has a 540 with 8 to 1 compression and the same AFR 357 heads as a test mule that makes 1100hp with 10psi boost on pump gas.. My 572 should make a few more HP. I think that should get the job done. Any guess to how long my IMCO Extreme SC drive is going to last, lol
I have a post in Do it yourself Boating on a Budget, lol
572 DFI Procharger build
I will post here my progress.

Cool