Swap Mercruiser 3.0L with 4.3L

[Baler]

I just bought a 2000 Bayliner 2050LX that has a bad motor. The motor did not get winterized and now has a cracked head. I am looking into replacing the current 3.0 with a 4.3 Mercruiser. I am wondering which additional parts I will need to purchase to do the swap or if I will have everything if I buy a complete engine? Is it reccomended to upgrade to the 4.3L? Is it worth the extra money? Where do you suggest buying the motor? Thanks.

 

[Bondo]

Re: Swap Mercruiser 3.0L with 4.3L

Ayuh,... You'll need a Complete motor, with All it's accessories, a Y-pipe, 'n a different drive...

Is it worth it,..?? Probably Not...

 

[Howard Sterndrive]

Re: Swap Mercruiser 3.0L with 4.3L

Not sure what you're budgeting or planning.
For what a new repower would cost from Merc, you could get a nice garage kept, well maintained boat on a nice trailer cheaper.

I did a V6 swap into my 1992 Bayliner 1851. pulled the 3.0. It was a lot of work, but I do enjoy the end result.

I basically bought a Y pipe, manifolds, and then bought a trashed V6 for all the peripherals. Then I used a new crate block I had and swapped in marine cam and brass core plugs. I fabricated my own front mounting pods to attach to the stringers. Had to buy a couple of weird things e.g. the shift interrupt switch and bracket (The 3.0 had it on the valve cover)

It made sense for me because
a) wrenching on boats is my hobby
b) I have lots of summer holiday time
c) I sold the 3.0 and used 1.98 ratio drive for same $ as I paid for the boat
d) my hull and interior are MINT.

Without those 4 factors, I wouldn't have bothered.

p.s. for a 2050, if I was to bother to upgrade at all, I would go V8, or 4.3 MPI but the latter is huge $

 

[Hogger]

Re: Swap Mercruiser 3.0L with 4.3L

Welcome to iBoats.
I don't know why anyone would put such a small engine in a boat that size to begin with.
I would definitely go straight for the V8 since you would have to swap the outdrive anyways. Then you could forget about dealing with the y-pipe and fab up some thru hull exhaust.

 

[Baler]

Re: Swap Mercruiser 3.0L with 4.3L

Thanks!! I will probably just get a rebuilt 3.0L. If I find it is not enought HP for pulling a skiier or wakeboard I can always sell it and find a boat with more HP. Right now our kids are small enough that we dont need alot to get them out of the water. We currently have a 1974 SeaSwirl with an inline 6 but bought the Bayliner for a good price and thought we could replace the motor and have a nice boat for a great price. Have you ever bought from Michiganmotorz? Do you have any suggestions where to look for a rebuilt motor? I really appreciate your help!!

 

[Hogger]

Re: Swap Mercruiser 3.0L with 4.3L

There are a lot of places on line. I'm buying a new 4.3L for my boat in about a month.
Just watch the shipping and core charges, even the warranties. Different companies will also sell engine at varying stages of a long block. Some without the "tin"(valve covers, timing chain cover, etc...), and some with it and more for the same price. I've found new engines, with valve covers, water pump, harmonic balancer, flywheel, even intake manifold, for the some price others were charging for a stripped long block. Make sure you get a marine engine.
Just take your time and shop around.

 

[Joshua Nichols]

Re: Swap Mercruiser 3.0L with 4.3L

That is a lot of barge for the little engine.(20ft?).. This is a good route to go.. Find a boat with a trashed hull with a good running mill the size you want... See em all the time... Sounds like a lot of work to me.. I like to work on my tub, but I rather go boating than busting knuckles..

 

[airshot]

Re: Swap Mercruiser 3.0L with 4.3L

That is a lot of barge for the little engine.(20ft?).. This is a good route to go.. Find a boat with a trashed hull with a good running mill the size you want... See em all the time... Sounds like a lot of work to me.. I like to work on my tub, but I rather go boating than busting knuckles..

Is that Bayliner a heavy boat? I am a bit surprised at all the talk about what a small motor the 3.0 is, I have found it to be more than adequate in my 22' Islander, typically can't run more than 22 knot in lake erie chop anyway and do enjoy the fuel economy. Lower fuel usage means more time on the water for me. Mabey I am just not the hotrodder that many appear to want. Hmmmmm...

Airshot

 

[86 century]

Re: Swap Mercruiser 3.0L with 4.3L

Why not use the I6 you have already gain some hp and not spend to much.

 

[fat fanny]

Re: Swap Mercruiser 3.0L with 4.3L

I have to chim in with my 2 cents that rig too big for a 3.0 my 17' Ray has a 3.0LX and it pulls it ok but I can tell it's at the top of it's power band when plaining and pulling tubes and skiers. Keep your current rig and hold out for a v8 and or v6 and piece it together a lil @ a time engine, drive and all the ecentials that way you can take your time to shop around and still be boating

 

[kaw]

Re: Swap Mercruiser 3.0L with 4.3L

I to am contemplating a 4.3,.I bought a 16' Sea Ray with a 3.0 I picked up very cheap because of cracked head, after closer inspection the block has 2 hairline cracks under the manifold, not sure if that can be repaired. Hull and interior is in good condition.
I have been checking prices and they are all over the board. Since mine is a 16' I would think the 3.0 would be plenty, but friends say to look into the 4.3. The cost is definetly higher. If anyone has purchased a motor from a supplier, I'm looking for a good recommendation.

 

[netting one]

Re: Swap Mercruiser 3.0L with 4.3L

I have two boats im trying to make one out of. One is a 1984 and one is a 1992 both 4.3 merc's i will have a extra outdrive,transom asm,exhaust and manifolds if this helps at all. I went out and found another boat for the motor and extra's. im using all the 92 parts

 

[Bondo]

Re: Swap Mercruiser 3.0L with 4.3L

I to am contemplating a 4.3,.I bought a 16' Sea Ray with a 3.0 I picked up very cheap because of cracked head, after closer inspection the block has 2 hairline cracks under the manifold, not sure if that can be repaired. Hull and interior is in good condition.
I have been checking prices and they are all over the board. Since mine is a 16' I would think the 3.0 would be plenty, but friends say to look into the 4.3. The cost is definetly higher. If anyone has purchased a motor from a supplier, I'm looking for a good recommendation.

Ayuh,.... Welcome Aboard,... Please start yer own thread, 'n not be hy-jackin' other's...

 

[Technorunner]

Re: Swap Mercruiser 3.0L with 4.3L


Where this one is sitting now there use to be a 3.0L
Its not impossible but you need to think its fun to do it.
I have custom made lots of things for it to work
But im thinking this V6 is abouot 220BHP and the small V8 302 is about the same hp with lots of more weight on it.
Sure its not the same sound but for me its worth it.

 

[ready4lake]

Re: Swap Mercruiser 3.0L with 4.3L

I am going to be swapping out my 3.0 for a 4.3 as well. I have a donor boat that I bought so all the parts are there. There is nothing wrong with my 3.0 except it has no business in a big boat(1989 bayliner trophy hardtop). It looks like my swap should be fairly easy since there are existing points for side engine mounts in my boat. I plan on starting this project within 2 weeks, and I will post lots of pics. This will be my first engine swap in a boat, so it will be fun.