smokediver
07-31-2005, 06:34 PM
I was finally able to take my boat up to full throttle for the first time today !! Not for any length of time , but enough to throw out some numbers . as many know , i have a 16 that had a 4.3 and i switched it over to a remanned 5.7 from mercruiser . the engine was setup for a bravo drive so the shifter and ecm had to be changed . the coupler is a bravo coupler but a alpha drive hooks right up to it with no modifications . the engine was bored .040 according to the tag on the side . i changed the upper part of the outdrive as i had a 1.81 ratio and changed to a 1.62 .. it was cheaper to buy the whole assembled upper than to get gears and have it switched over .. i paid 595.00 for it and got a 2 year warranty . i paid 4000 for the engine , turn key drop it in and go . I switched the cast iron manifolds and risers and replaced them with a glm aluminium set . I am running 4 inch straight exhaust . OK, now the good stuff ... turning a 25 pitch laser 2 at 4800 rpm gave me 62.5 mph on gps . I picked up a solid 5 mph over the 4.3 ... My next plan is to get more time on the engine , and when i feel it is going to be good to go , i am changing the intake to an aluminium 4 bbl .. Trailer Boat mag did this upgrade and gained 6.1 mph on a 21 foot rinker ...
I can honestly say that while there is only a 5 mph difference in the 2 engines , the acceleration is night and day ! the exhaust sound alone was worth all the long hours !!! I wish I would have compared the different manifolds and risers but my back thanks me for not doing so ! Thanks alot for all the answers that i was looking for .. I am noticing as the engine is getting broke in , it is running cooler ... around 160 - 170 ...
I can honestly say that while there is only a 5 mph difference in the 2 engines , the acceleration is night and day ! the exhaust sound alone was worth all the long hours !!! I wish I would have compared the different manifolds and risers but my back thanks me for not doing so ! Thanks alot for all the answers that i was looking for .. I am noticing as the engine is getting broke in , it is running cooler ... around 160 - 170 ...