Can I up engine size?

[Biggins1225]

Well want to say this site has been great help for me on my 94 1800 sr2. I am still haveing issues with my engine spinning the same main bearing even after new crank and bearings with new caps all the way threw the bottom. Think I am going to look for another engine instead of rebuilding this one for the 3rd time this year. So I was wondering While I was shopping for engine if I found a bigger engine than my 4.3lx like say 5.0 or 5.7 for little more what would I have to change to make it work? Or would it be better to go back with the 4.3 agean.

[shrew]

Hi Biggins. You might have to change the motor mounts and pipes from the risers to they Y IF you can squeeze a V8 in the space. I'm sure someone with much more knowledge will pipe in. I'd go with another 4.3.

[ss3964spd]

Spinning the same main after installing a new crank, bearings, and main bearing caps? Can be the following:

Bent crank (just because it's new doesn't mean it's straight)
Crank journal size is wrong (just because it's new doesn't mean the journals are correct)
Bearing size is wrong
Oil feed to that main is restricted somehow
When the main caps are replaced the block MUST be line-honed

Stepping up to a V8 in place of the V6 can probably be done but it will definitely be more costly. In addition to the engine, pan to carb, you'll need new exhaust manifolds and risers at the very least, and you might have issues using the accessories from the V6 (power steering pump, alt, etc) because the V8 is longer than the V6 so the hoses and wiring may not be long enough. And of course, you'd have to find out if the boat was designed to accommodate a V8.

Dan

[GlennW]

Depending on your drive you may also need to change gear ratio.
I would go with a new long block 4.3.

[deanries]

Hi Biggins-

I know on the transom on my '92 1800SR it is printed what the max hp allowed. I would be sure to check that out first. No need to lose the whole boat just to have a V8. Get a warranty on any engine you buy plus stay with the 4.3 if it were mine. Good luck getting her back on the water!

Dean (deanries)

[Biggins1225]

K thanks guys, I was just checking on the v8 becouse local shop said they would have one in few weeks. They have a long block 4.3 but dont know what model it is and it's been in storage for two years for $600. They said it was good engine when they put it up.