6.2 internals in a 5.7 ?

[rider01]

Hello all, new to boats as well as this forum.
I recently acquired an 01 Baja 212 Islander, with a cracked block and 100hrs on the meter. I'm wondering if I can replace the block with a vortec 5.7 block, I looked and the part numbers are the same for the pistons and rods for the 5.7 as they are for the 6.2. But, the mail bearings show different part numbers. Does anyone know what the difference is, I know the crank has more stroke, but are the mains a different size?
Thanks in advance for all the help.

 

[Bondo]

Re: 6.2 internals in a 5.7 ?

Does anyone know what the difference is, I know the crank has more stroke, but are the mains a different size?

Ayuh,... They're Bigger....

It ain't Just swappin' the internals,...
There's Machine work involved...

 

[rider01]

Re: 6.2 internals in a 5.7 ?

Thanks bond-o, that's kinda what I thought, but finding any info on this motor is like searching for a needle in a haystack. So I could have my block line bored to allow for the bigger mains, or turn the cranks mains down to work in the 5.7 block.
Is there somewhere where I could just buy a new block?

 

[Bondo]

Re: 6.2 internals in a 5.7 ?

Thanks bond-o, that's kinda what I thought, but finding any info on this motor is like searching for a needle in a haystack. So I could have my block line bored to allow for the bigger mains, or turn the cranks mains down to work in the 5.7 block.
Is there somewhere where I could just buy a new block?

Ayuh,.... Google up Buildin' a Chevy Stroker motor, or 383 Chevy...

It's done everyday, All day long...

 

[rider01]

Re: 6.2 internals in a 5.7 ?

I'm very familiar with the small block chevy, I built a 383 stroker years ago for my 69 Camaro. The thing that was throwing me off was the 377ci, it finally dawned on me that a standard bore would be 377, not 383, duh! But when I built my 383, it didn't require any special main bearings, the crank main bearing journal was cut down to the size of a 350. Now you can buy an aftermarket crank with the right sized mains, no machining.
Again, thanks for the help, I look forward to learning alot from this sight.

 

[alilley]

Re: 6.2 internals in a 5.7 ?

this is just a spin on your 377 thought and this is coming form the dirt track guys..... 383 is a 350 with a longer stroke (usually a crank out of a 400 or a kit) a 377 is a 400 that has been de stroked with a 350 crank in it.....it all depends where you want your power curve to be as a 383 will have a low rpm power curve and a 377 will have a higher one.....

 

[TilliamWe]

Re: 6.2 internals in a 5.7 ?

...383 is a 350 with a longer stroke (usually a crank out of a 400 or a kit) a 377 is a 400 that has been de stroked with a 350 crank in it........

Not in the world of math and not in the world of Mercruiser. A 400 (4.125" bore) witha 350 crank (3.48") would result in 372 cid. To make their 6.2LX and their 377 Scorpion motors, Mercruiser takes delivery of brand new 5.7s from GM and modifies them. The 383MAG MPI that Mercruiser offers is a factory remanufactured engine, again from 5.7s they take on trade or they used in testing. Quite simply a 377 is a 4.00 bore with a 3.75" stroke. A 383 is a 4.03" bore and a 3.75" stroke.
rider, if you are going to build a boat motor for power, don't build it like you would a car engine. You can't get the lift/duration too high or you will have exhaust water reversion issues. And of course, as with any SBC, you don't NEED a lot of carburetion. So leave the Holley 750 double pumpers on the Summit shelf! Dennis Moore wrote a book about building small block Chevies in boats, it's worth time/trouble/expense to find it and read it.

 

[rider01]

Re: 6.2 internals in a 5.7 ?

Thanks for the reply Tilliam
I don't plan on trying to build a bunch of horsepower. The 320 that's advertized will be plenty. I plan on using all the internals from my engine, cam, pistons, crank, etc. My motor only has 100 hrs on it.
alilly, when I heard this engine was a 377, that's the first thing I thought, was they de-stroked a 400, but if you look at the specs of the engine it is indeed a 4inch bore and a 3 & 3/4 inch stroke.
Thanks to all