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Upgrading twin 4.3 to 5.7 suggestions.

Pzilly

New member
Hey there follow bankers, oh I mean boaters, sorry humor is all I have left at this point LOL.

So this summer has been exceptionally hard on my wallet and mind with boating, already in progress on replacing the 2012 x45 master crafts very expensive ilmor motor, outdrive on the ol reliable 4 winns is in the shop, and now found a crack in one of my 4.3 motors inside the cylinder in my 2760 Regal Cruiser. At this point I think I might go back to instructing skydiving in the summer, that actually pays me, and if it goes wrong nothing to fix anyway plus its awesome... LOL

So being that it's end of season I'm going to pull the boat out in two weeks, ive already got the heads off and found my crack, I'm going to pull the rest of the engine soon then over the winter I need to decide what to do, I know there is room in this boat for twin v8s it is a Regal 2760/2860 with twin 4.3 that was also offered with a single big block engine I'm looking for help with setup for installing twin 5.7 V8s in this boat.

Have any of you done something similar? I figure I will need to move motor mounts about 4" which is no big deal, and I'm sure I'll have to re gear the alpha drives and being this boat had the dreaded 1 piece ex manifolds I am guessing reusing my existing Y pipe might be an issue since I had to buy adaptors when I recently switched one to 2 piece hoping that was the water in oil issue.

my 4.3's are EFI and i know the TB is same for 4.3 and 5.7 of those years, I also see they are no longer supported, so trying to find the most cost effective way to do this upgrade, boat is mint, and although I wouldn't say it's under powered for the average boater, for us and all our stuff, towing seadoos, and being a former super charged Baja owner I am seriouly considering this because what caused my issue was 2 cooling ports full of rust which blocked the RV antifreeze from getting into the top part of the block, so chances are the other motor is probably similar, so if I'm switch one, might as well sell a kidney (some one else not mine LOL) and go big. I would seriously have eaten off these two motors, but 18 years seems to have taken a toll on the internal cooling system, and because all cylinder were at 150 psi except the bad one which was still 138 psi, test actually convinced me problem was the 1 piece manifolds at first,me they are still good running...


any input is appreciated, any good jokes to keep my sanity is welcome, donations gladly accepted....

Thanks in advance, and hope your season went better then ours LOL...
 
As you have noted, the cost is going to be very high to replace the engines with something different. I think you should repair what's there or sell the boat off and get one with the power you want.
 
boat is mint,.................. I am seriously considering this

any input is appreciated, any good jokes to keep my sanity is welcome, donations gladly accepted....


Let the Nay-Sayers say what they want to.
If you like the boat, if it's in great condition and if you have the budget for this........ go for it!


Oh.... here's my donation.


 
If you like the boat, if it's in great condition and if you have the budget for this........ go for it!
[Begins long winded narrative on quench-effect pistons]

I say in for a penny, in for a pound (even if Brexit fears have hammered the GBP lately, you get the idea) and get a quote for the entire package of two new engines and drives. See if they'll take any of your old stuff in trade-in value and you may be pleasantly surprised at the total. With long term financing you shouldn't be too much out of pocket up front.
 
With long term financing you shouldn't be too much out of pocket up front.

I think that financing a pleasure boat, or pleasure boat parts, is like tossing common sense into the wind!
These are toys, not essentials!
 
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