Burned Piston- new block?

[ProdriveMS]

Hello new member here. I got a great deal on a 97 Sea Rayder Jet Boat with a bad engine. The previous owner took the engine apart and it looks like it had horrible detonation. There is aluminum slag on top of all the pistons. The number 2 piston completely melted, fell apart and as pieces of it and the rod went through the engine, it cracked the block and broke the sleeve. Now I work at a machine shop and worst case I could weld up the block, resleeve the cylinder, and machine everything back to stock but it will be a ton of work. The better option might be to find a rebuildable block.

My question is, what blocks and years would interchange. The powerhead is a 97 mercury 2.5L 175hp v6. Would a 200hp powerhead fit? Can it be a pre 1997 model? What are my options? I'm trying to do this as inexpensively as possible, but I have all winter and access to a machine shop. Also, what should I look for that caused this to happen? Thanks

Al

[JR IN JAX]

If it is worth the money you can get a new or rebuit Mercury Marine powerhead. I got my best price from Jacosmarine.com.

[rock]

I have a couple fresh 175 xri rotating assemblies. Block, cover, crank, rods, pistons with new rings. 1 of them is standard bore and one has a couple oversize holes.
Rock

BTW......Welcome to the site.

[Riverratt]

I think the motors are the same but the crank has different splines in the sport jet motors.

[Markus]

I think the motors are the same but the crank has different splines in the sport jet motors.

Yes, that's my memory as well.

[rock]

If that's the case, and I don't doubt it is, these motos will do you no good.
Rock

[ProdriveMS]

Can I take my SJ crank then and drop it into any 175 or 200hp block?

Al

[Riverratt]

I am under the impression yes but I am not positive. I am pretty sure the only difference was the driveshaft splines in the crank. I think Raceman on here knows the answer for sure.

[ProdriveMS]

What about the older pre-1997 blocks. I think they were 2.4L. Can the rotating assembly be swappen into those? They are much easier/cheaper to com across.

Al

[beamrverbeek]

the crank spline is different on the sj cranks. and 2.4litre stopped in 91 with a 2.5 block that had 2.4 sleeves in it, it was called a fat block by many people. if your crank is good then you can put it in any 2.5 that has the same size bearing on the top. you can even put a 2.4 crank in a 2.5 as long as its a matching bearing diam.