I like the sleeper idea. I did it :)

Though with my boat, there was no resale value to kill and the base motor was all there.

92' 221 Four Winns Liberator
The stock 502 built to fairly mild specs, converted to roller, Madera cam, good exhaust, blah blah blah. Dynoed 539, runs low seventies ALL day and ran about 62 when it was stock. I'm sure it's seen higher than this GPS in a mild chop and just me, but I don't carry my GPS very often. ~10mph gain over the base 420hp 502. It will catch a lot of unsuspecting mid-level performance boats off-guard. Cruise 3200-3300rpm ~43-44 mph and off the secondaries.

http://i1268.photobucket.com/albums/...ps95144561.jpg

http://i1268.photobucket.com/albums/...psfc25a60b.jpg

http://i1268.photobucket.com/albums/...ps14ca0aae.jpg


http://i1268.photobucket.com/albums/...psxttkurou.jpg

Papa, just to give you a little encouragement, a buddy has an 89 Baja Force 235, which is an even older hull design than yours, and was seeing low 80's with a B&M 250 charged 502. Boat was getting a little squirrelly at those speeds, but was fine at 75 and below. For the most part the boat was turn-key reliable. He ran the bag out of it and put hundreds of hours on it before a connecting rod finally gave up. He ran an XZ drive on it that was also pretty reliable, but we mostly run on lakes and rivers around here so no real big water. He is now running around 70 with an HP500 clone. I think you will hit your goal easily with Mark building you a 700HP motor.

Love this build. Keep us posted on progress!

What prop you running? I'm running a 23 mirage seeing 69/70 mph. Just curious.

That last pic is the money shot! Thats what lake boating is all about! Sorta fast boats, and happy drunk women on your boat!

You can follow the build on my FB page, under Eric Stevenson or Formula owners of the Carolinas FB
Mark is posting pics up as the build progresses and its kinda of fun to share

Speaking of props........................

Boat weighs 4525 lbs dry, 88 gallons of fuel capacity, will have 700 plus HP. Bravo1 geared 1:50

Was thinking Bravo 1 BBlade Labed 30P

Thoughts?

Keep plugging, it will make you happy when you are done and that's what matters!

That's probably too much pitch. What maximum rpm are you planning to turn with the new engine?

BAM has a speed calculator http://www.go-fast.com/boat_speed_predictions.htm and prop slip calculator http://www.go-fast.com/Prop_Slip_Calculator.htm.

Running your numbers and assuming 5500 lbs loaded, 650 HP at the prop shaft and a 225 constant, it comes to 77 mph. Assuming you turn 5200 rpm and have 16% slip, a 28P prop puts you at 77 mph.

Not 100% sure, but I think Mark is setting up engine to max out around 5600 Sent him a text, so will let you know for sure. I know Bblades has a demo program, and I have a business UPS account, so I may demo a 28 and a 30 and see what works best
Thanks for your interest and help. We want to spend a week at Lake of Ozarks one summer. Seems like that place is Formula heaven!