1989 celebrity 268SE 5.0L spun bearing, repair or swap

[jdknech]

last weekend one of my 5.0L's lost oil pressure and (I'm guessing from what it sounded like) spun a bearing or 2, my debate at the moment is-
1.rebuild the 5.0L that I have and re-install, (has side bolt valve covers and a mec. fuel pump SN# B481950 230HP) or,
2. buy a used 96+ vortec engine and rebuild using a carb intake and install in place of the 5.0.

this is a twin engine boat, so I know I would have to swap both engines, but how much of a direct swap is this? can I use the bellhousing and coupler and flywheel from the 5.0? or is all that stuff different? what about the front accessories, can they be swapped? can I use the 5.0 dist. and coil?
I know I would have to use a electric fuel pump with the vortec, is that the only major difference?
I can do the rebuild on either engine fairly easy and cheap with marine parts, I just don't want to run into compatibility issues doing the swap.. I'm kinda on a budget of sorts lol

any help is appreciated! I do have experience rebuilding engines (I do 1-2 car/truck engines a month for extra side money) but this is my first experience with a boat engine.. this is my personal boat, not a customers, so I don't mind trying out of the norm stuff with it.
thanks-

 

[Fishermark]

Going from a two piece rear main to a one piece is the bigger issue. Not not a big problem. I believe you will have to change out the coupler.

If you are going to go through the trouble of changing out both engines, it is a good idea to go with the 5.7 liter vortec - not the 5 liter.

 

[jdknech]

Going from a two piece rear main to a one piece is the bigger issue. Not not a big problem. I believe you will have to change out the coupler.

If you are going to go through the trouble of changing out both engines, it is a good idea to go with the 5.7 liter vortec - not the 5 liter.

sorry, I should have put that in there, if I do the swap, I would DEFINITELY use a 5.7.. I already have a line on 2 rebuildable 5.7's for $150 each.

On the coupler, is it just a standard coupler for a 350 vortec marine engine, or a special conversion coupler?
thanks- Josh

 

[Fishermark]

It is not a special conversion coupler - you simply need the correct flywheel and coupler for the engine as they are different.

By the way - if you do need to use the electric fuel pump, be sure to include an oil pressure switch that you will need to wire it through.

 

[Scott Danforth]

Or build a motor from a post 1988, pre 1993 block with vortec heads. This would give you a mechanical fuel pump block. Got to love the Mr potato head SBC

 

[jdknech]

Or build a motor from a post 1988, pre 1993 block with vortec heads. This would give you a mechanical fuel pump block. Got to love the Mr potato head SBC

this is a good thought... I might look into this.. how much of a difference do you think I would notice going from a 305 to a 350 with vortec heads? or even a non-vortec 350?

 

[Silvertip]

Lost oil pressure is a rod/main bearing issue but that alone does not mean the engine needs to be dumped in the bin. If it had not been using oil and was otherwise performing ok, why not pull the engine, pull the crank, have it machined if the shop says its ok, install new undersize bearings, reinstall the engine and go boating. You wouldn't even have to pull the rocker covers unless you wanted to re-seal them. You end up spending a lot less money than rebuilding two engines of questionable quality as well as spending additional money on conversion parts and dealing with the headaches involved with not one but two engine swaps. If the current engines both have high hours then perhaps fresh 5.7's are the way to go. Don't forget that new props would likely be in order as well with the engine swap.

 

[Scott Danforth]

this is a good thought... I might look into this.. how much of a difference do you think I would notice going from a 305 to a 350 with vortec heads? or even a non-vortec 350?

going from a 305 to a vortec headed 350 would add about 70hp to the crank from a 305 to a non-vortec 350 is about 40hp

 

[jdknech]

Lost oil pressure is a rod/main bearing issue but that alone does not mean the engine needs to be dumped in the bin. If it had not been using oil and was otherwise performing ok, why not pull the engine, pull the crank, have it machined if the shop says its ok, install new undersize bearings, reinstall the engine and go boating. You wouldn't even have to pull the rocker covers unless you wanted to re-seal them. You end up spending a lot less money than rebuilding two engines of questionable quality as well as spending additional money on conversion parts and dealing with the headaches involved with not one but two engine swaps. If the current engines both have high hours then perhaps fresh 5.7's are the way to go. Don't forget that new props would likely be in order as well with the engine swap.

the voice of reason has spoken! I will most likely do this, but for my piece of mind, the whole engine will get resealed... I have the engine out, and there is very little oil in it, so it was burning oil pretty good apparently.. the engines have just a shade under 700 hours on them... is that high hours for a boat?

 

[jdknech]

going from a 305 to a vortec headed 350 would add about 70hp to the crank from a 305 to a non-vortec 350 is about 40hp

very good info to have! thank you sir!

 

[Silvertip]

Very little oil in it???? How often do you pull the dip sticks and check the oil? I hope your answer is before every trip. If not, then grasp your right hand index finger with your left hand and point that finger back at yourself as the cause of bearing failure. 700 hours is not a lot of run time but that depends on the amount of abuse, operating conditions and preventive maintenance the engine has seen.

 

[jdknech]

Very little oil in it???? How often do you pull the dip sticks and check the oil? I hope your answer is before every trip. If not, then grasp your right hand index finger with your left hand and point that finger back at yourself as the cause of bearing failure. 700 hours is not a lot of run time but that depends on the amount of abuse, operating conditions and preventive maintenance the engine has seen.

This was the only time out without checking the oil, BUT it wasn't lack of oil that caused the failure, it appears that it was a improperly installed rod bearing.. The reason it didn't have oil was because when it threw the rod, it punched a good sized hole in the pan and dumped it all in the bilge.. I found all this after pulling and disassembly of the engine

I ended up buying a 1984 2 piece rear main 350 4bolt main, and its currently at the shop getting cleaned, bored, and the crank turned.. And the heads gone through.. I should only be in 1000-1200 after its all said and done hopefully.. Then I'll find another 350 to build up for the other 305 and swap it out at the end of season.,
It'll be interesting to see what effects it'll have with a 305 and a 350 in it lol

 

[redmen62]

It's different but manageable... A dockmate of our ran a 89 350 (260hp) and brand new 350 mag (300hp) when he lost his port engine. Which engine are you swapping to start? If it's the starboard, you'll really notice it because your lower units both spin the same direction (clockwise), so when you maneuver with your engines you'll really got some torque steer and notice your stern drift

 

[jdknech]

It's different but manageable... A dockmate of our ran a 89 350 (260hp) and brand new 350 mag (300hp) when he lost his port engine. Which engine are you swapping to start? If it's the starboard, you'll really notice it because your lower units both spin the same direction (clockwise), so when you maneuver with your engines you'll really got some torque steer and notice your stern drift

the starboard is the engine that's getting swapped out, I guess we will see what it does...

the engine is getting bored .30
a performance Marine cam (unsure of specs or brand yet)
a FULL master rebuild kit, only original parts are the crank and rods
crank will have to be turned unfortunately, but not a big deal

I am planning to bolt up the 2bbl intake from the 305 and run the same carb, will it need to be rejetted, adjusted, or can I leave it be?

 

[redmen62]

It'll for sure need to be adjusted.. I'd be interested in what kind of performance you'll get out of the 2bbl carb. I don't think I've ever seen a 2bbl on a 350 in a marine application

 

[harleyman1975]

We had twin 350 2bbls our '96' 290 Chappy. She did 47 gps

 

[jdknech]

It'll for sure need to be adjusted.. I'd be interested in what kind of performance you'll get out of the 2bbl carb. I don't think I've ever seen a 2bbl on a 350 in a marine application

I guess we will see, I'm hoping it restricts it a bit to closer match the 305 on the port side.. when I change out the other 305, they will both be getting new intakes and 4bbl carbs. I should hopefully be getting the engine back from the shop this week!

 

[jdknech]

We had twin 350 2bbls our '96' 290 Chappy. She did 47 gps

good to know.. I was getting 44-45mph (GPS) on the 305's so maybe the twin 350's get me closer to 50-55mph