FIXX

iTrader: (2)

ok if you can get a 502 block that would be better for you,,thias way you can either keep your 330 and stick it in the corner and save it for when you sell the boat to just stick it back in..you will need a torque monster to get that thing to 60..get the 502 and put the 4.250 stroke in it..with 4.500 bore and that crank you will have a 540..if you stick with a 575 lift cam and around .226 .236 E @ .050 that rite their will put well over 60..but like mentioned your drive will take a beating..if you can find like qa 1.62 bIII that would be better and you may not have to change props..

oregondunes

iTrader: (3)

so when you do a .25 stroked crank, what length rod do you use and do you have to then run a specific piston with either a raised or lowered pin height ?

are their also any clearance issues with the block that need to be dealt with ?

what about the counter weights on the crank ?

With the cam spec's you mentioned, I assume you would use a 1.7:1 ratio rocker ??

The B3 drive is supposed to be able to handle 500hp. Ive heard that the XR stuff will go in it and make it a bit stronger. It's not like Im gonna be doing WFO everywhere, kids cant hang on that well.

Griff

You would be lucky to to hit 55mph with 500hp in the boat you have.
You would be money ahead just buying a Merc 500HP and selling your 330.
Have some $$ set aside for outdrive repairs.

oregondunes

iTrader: (3)

My feeling is Id need to have a bottom end that can handle the blower and thats what Im building first.

I like the looks of the side mount whipples but fear the reduction in economy

picklenjim

You can use stock length rods or go longer.

You will need pistons to match stroke and rod length and give you compression ratio you desire.

No big deal on block clearance with 4.25" stroke. Maybe a little grinding.

Crank counterwieghts no problem except may turn into an expensive balance job.

FIXX

iTrader: (2)

with a 4.250 crank it would be best if you went with the 6.385 rod legnth, with that combo it puts less stress on the cylinder's side walls..yes you would also need the relocated piston pins...if you plan on supercharging this engine you will want to step up on the rispins to make them a little thicker to support the boost..you will have to notch the oil pan area for connecting rod clearance..simple job with a carbide bit and a air wizzard...you need about .100 of clearance..i like to go a little more if you can get away with it..

Knot 4 Me

Have you weighed the boat/trailer and then just the trailer to get an accurate "wet" boat weight? I think you will be surprised just how heavy that boat is with gear/batteries/fluids. My 260 Chaparral tips the scales at over 6K and your Mariah is a much bigger boat. I can only run 53 MPH GPS with a 496 MAG/Bravo III with a 26" BBlades tuned prop set. IMO, you are heading down a very expensive and frustrating road trying to turn your family truckster into a performance boat. If you like the size and layout of your boat but would like 60 + MPH performance, I would look to get out of your current ride and look for a MCOB with twin small-blocks. For example, a 32 Sunsation MCOB with twin 6.2's will run 68 - 70 MPH GPS depending on load/conditions and will knock down better cruise GPH numbers than your Mariah does stock. This is just one example. There are several boats out there that have more performance-oriented hulls that will achieve the speeds you are looking for much more efficiently. Something to consider.

oregondunes

iTrader: (3)

book says 5850 lbs. anything close to 55 would be great compared to the 42 I get now. just frustrates me when wake board boats pass me and their fat sacks are full.

Knot 4 Me

My book says 5,400 on my boat. My 6K Poly Lift could barely lift it out of the water full of fuel. The book doesn't take into account gear, batteries, water, fuel, etc. Plus production boats can have quite a variance in weight. A buddy of mine used to be a Merc tech at the local Rinker dealership. I was shooting the bull with him one day while he was installing thru-hull exhaust on a 232 Rinker. He showed me the cutout on each side of the hull and I about shat. The thicknesses were way off side to side. He then grabbed a handful of cutouts from other boats and not one was the same thickness. The thickest was more than twice as thick as the thinnest piece. So unless you hit a CAT scale you will never know exactly where you are at. I bring this up as I know a guy that had a 22' Crowinline with a 502MAG that put on a side-mount Whipple. I can't remember if the upper gear or the verticle shaft went bye bye quickly in the drive. That is in a much, much lighter boat than your Mariah. I think you could sell your boat and pick up a boat that will meet all your boating criteria (and be more reliable and efficient) for about the same money you will end up spending on motor/drive upgrades. Maybe less.

oregondunes

iTrader: (3)

all great info, thanks. it wont be til late spring before I splash it again. when I do, I will get a weight