Replace/Repower 1984 Mercruiser 260 Freshwater cooled

[ddclapp]

Good morning, I need some expert advice on re-powering my 1984 Tiara Pursuit which has a original 1984 Mercruiser 260 with fresh water cooling. After evaluation of rebuilding and fixing the existing I have decide I would rather repower and go with some newer technology. What engine is the appropriate replacement for this old model? I am seeing 5.7 liter MIE online for 7K or so, but not sure what technology I should be looking for and asking for.

Any advise is greatly appreciated. Exact models to look at, estimated cost of swapping out, any hidden costs that can be thought of?

 

[Bondo]

Exact models to look at, estimated cost of swapping out, any hidden costs that can be thought of?

Ayuh,..... So yer lookin' to buy a brand new Merc fully dressed, Bobtail crate motor,..??

Or are ya lookin' for a Reman, fully dressed Bobtail crate motor,..??

What exactly is the diagnosis of the current motor,..??

Are ya lookin' to stay with a Carb, or go Efi,..?? Mpi,..??

 

[alldodge]

As Bondo mentioned, it would be good to know which way your leaning, but without that I'll say:

I would suggest, replacing with a newer 5.7 vortex motor, 1996 or newer model. If your in salt water, suggest going full closed cooling, replace the transom assembly and go with a Bravo 1 if not a 3 drive

Change that, you said fresh water. Would still suggest the B1 or 3 drive

 

[flipbro]

5.7 vortec carbed would be a nice engine in that boat.

 

[NHGuy]

The EFI engines run best, but the carb engines are easier to service.

 

[ddclapp]

Thank you all for your feedback/advice.
Bondo - remember you are talking to a "Cadet" here! I am considering both a new motor and a re-manufactured. Please advise on "Bobtail Crate", I am assuming you mean a drop in shipped to you motor? What is "mpi"?

My goal here is to get several years of low maintenance boating. My schedule does not allow me to properly take care of the old motor with continual parts replacements and troubleshooting. I want to go boating more and repairing less! Right now I am looking at several thousand to get up and running after a few years off.

When I said fresh water cooled, I meant I have closed cooling system (not raw, salt water). I do want to stick with this.
I have got a quote from a reputable company, for a Mercruiser 356, 275 HP, for 7K, with an additional 2K for the closed water cooling. This seems be going price with searches on google. How would this compare with the 5.7L Vortec? They say they would install this in the boat for 1500.00 for a total package replacement cost in 10.5-11K range.

Also, I failed to mention, I have a Sterndrive Engineering Alpha One, Gen II sterndrive that is only 5 years old, I would like to stick with. Is the Vortec 5.7 compatible with this setup, as you mention the Bravo with this AllDodge?

Carb, EMI or Mpi. Because I am only used to the Carb, I have not experience with the others. Does the EMI give better efficiency? What is Mpi? What about cost difference, and longer term maintenance?

Thanks again to all.

 

[alldodge]

The 356 with 275hp is a remanufactured 5.7 motor, bored .030 over. The reman should be vortex and just make sure it is a 1996 or newer block. Vortex or non-vortex is the same block, everything fits, the vortex is the type of heads on the motor.

Can get a new 377 with 340hp, all EFI, smartcraft but much higher. The best way would probably be to stick with the reman and newer then 1996. Understand you want to stick with closed cooling, but closed cooling won't be that much of added value for fresh water, other then ease of winterization. My 94 Rinker has not been touched and is all original.

EFI is electronic fuel injection, and there are two types. TBI Throttle Body Injection and MPI Multiport Injection. The EFI motors start quicker, no pumping of the throttle and throttle response is smoother. But for simplicity, carb is still a very good setup and if taken care of will last a long time. If there are problems with a carb motor, there is not much need for special instruments, but EFI models most need a scanner to read codes

 

[redmen62]

I just helped a guy I boat with drop in a carb'ed 357 last winter... mounted right up (after alignment) to his alpha one. He just had it shipped to him, and we installed it in 1 day, and got the carb and everything 85% tuned and dialed in the next (as best we could not being in the water... January in WI isn't very boating friendly!). As long as you're diligent about labeling things when you take the old one out, it goes in really easily.

I would consider sticking with a carb if that's what you know

We did his port engine last year, and are planning the starboard next winter

 

[ddclapp]

As you all figured out I meant "Mercruiser 357", not "356".

OK, I think it I'm narrowing it down - Mercruiser 357 Vortex 5.7L, 275 HP, Carb, closed cooling.

So now specifics: It seems that the standard Mercruiser cooling package is $2K, and is only a 1/2 system (uses Alpha One pump) and only cools block. Currently, my system has a raw water pump under the engine, and must be classified as a "full" system (block and manifolds). Which do I need on the new. Seems like the aftermarket 1/2 system is 1K but will void warrantee from Mercruiser?

I talked with Doug Russel Marine in MA, and also Michagan Moterz, and seems like no good answer from them...Any other reputable places to check prices?

 

[alldodge]

Merc warrants the motor, if you have a half system or full system, they are warranting the motor. If the cooling system is also theirs, they warrant that also.

If your going to use a belt driven water pump then you should have a Bravo drive.

The ones you mentioned and good folks. It doesn't matter where you buy the Merc reman, you get the same warranty, price is the only difference. Now if your going to have a dealer put it in, then this could be an issue, check before buying. As for warranty work, any and all dealers do warranty work. I picked up my last new Merc purchase from Gavin Marine out of Iowa.

 

[ddclapp]

AllDodge, can you explain your reasoning why I would need a Bravo outdrive for using a belt driven pump? I would rather not use a belt driven pump if I do not need it - I would rather just use the Alpha drive impeller. My questions was really: Do I NEED a belt driven pump and full closed circuit (block and manifolds). Or will I be fine with a 1/2 just cooling the block, on the Alpha intake?

 

[alldodge]

Guess my misunderstanding of your comment of the belt driven pump, thought you already had one. You don't have to convert if you want to stick with the alpha. If you increase in HP your going to need the belt drive pump, alpha does not move enough water