Replace 4.3L with 5.7L in Rinker Captiva 192

[JASinIL2006]

Hi all, a friend of mine has a 2006 Rinker Captiva 192 Alpha One Gen 2 that he bought nearly new, although when he purchased it, the original engine had been replaced with a 1998 4.3L. (I don't know what happened to the original, but I suspect it was ruined and replaced with an older motor so the boat could be sold for a quick profit.)

Anyway, for years he's been unhappy with the power produced by the 4.3L and he's thinking of swapping motors. I suggested he look at something like a 5.7L. From what I've read here, it sounds likely that the front motor mounts will need to be modified, and I expect he'll need to change the upper part of the outdrive to get a gear ratio more suitable for the V8.

My questions:

1. Other than the engine, front engine mounts, and likely the upper unit on the outdrive, what would need to be changed? I'm assuming he'd get a fully dressed 5.7 from someplace like Michigan Motorz. Exhaust pipes? Coupler? Electrical harness?

2. The big question: how difficult is this swap? I would be willing to do the work with him. I'm no mechanic, but I have pulled the 350 Mag in my boat when I restored it, so I'm a bit familiar with the process. I don't mind doing research and learning new stuff, but I don't want to get into a project that's completely over my head.

Any thoughts on this swap would be welcome, as would links to threads where others have done this. (I tried the search function, but I find that mostly frustrating to use...)

Thanks!

 

[Rick Stephens]

Easy swap, new mounts and replace most everything attached to the motor, somewhat expensive. Needs 3 or 4 more inches of clearance to the doghouse in front of the motor. Unless he finds a way to offset some of the cost he'd be cheaper to sell his boat and buy one with more horsies under the hood. And gets to go boating.

 

[JASinIL2006]

I think he'd be selling the take-off engine and parts. The 4.3L runs fine, he just thinks it's underpowered.

He'll have to look at the cost of swapping engines vs. buying a different boat. Used boats are really expensive now, and in our area, where there are fewer to start with, boats tend to cost a lot more than in areas with lots of boating.

 

[Scott Danforth]

the easiest way would be to pull the 4.3 bobtail and install a 5.7 bobtail.

that is also the most expensive way. however gets the boat back in the water faster.

for me, I would buy a 5.7 motor (or build one)
buy a voyager distributor for the V8
buy exhaust manifolds for the 5.7
migrate the front accessories from the 4.3 to the 5.7
migrate the starter from the 4.3 to a 5.7
move the engine mounts

then regarding prop and gearing. if the drive is a 1.62:1, just change props. if the drive is a 1.81:1, you need to change gear set.

 

[Lou C]

Other than cost of odds and ends, the main things are the outdrive gear ratio as noted and how long the engine mount stringers are. If they are long enough figure approx 3.5"--4" in front of where the mounts are now then you won't have to do 'glass work.
One last thing first...is the 4.3 a 2bbl or a 4bbl? Because if its a 2bbl, a good performance enhancement is to buy a 4bbl intake and carb. That should add approx 30 hp or so. Not the same obviously as the 5.7 adds a lot of torque, but very easy and only about $700 in parts depending on how you buy them...I have a 4bbl on my 4.3 and it was rated at 205 hp vs the 2 bbl being rated at 175.
A 4bbl 4.3 should be at least adequate on a 19' boat.....

 

[JASinIL2006]

Thanks for the guidance, guys. My buddy is a very big guy (north of 300 lbs.) and with him and a boatload of passengers and gear, his Rinker does seem kind of sluggish.

I don't know about the carb... I'll inquire and see if that might be an easier/cheaper upgrade.

Scott Danforth , what all is included among the 'front accessories' you mention? Alternator? PS pump? We'd be looking at a longblock, then, yes? (Again, not an engine guy, so trying to keep clear on the terminology (i.e., bobtail vs. longblock vs. turn-key).

I need to look at his boat, but I am pretty sure they could be ordered with something larger than a 4.3, so I'm hoping the mounts might already be there...

Thanks again, especially for your patience as I master some of these terms...

 

[Scott Danforth]

Yes, everything bolted to the front of the 4.3 would be migrated

that would be buying a long-block 350

a long block is Heads, Block, rotating assembly, usually with damper and flywheel and in most cases an intake manifold

a bobtail is a complete boat motor assembly without the transom shield and outdrive

a longtail is complete from pulley to prop (and in many cases has controls)

agree with Lou, if your gravity-enhanced friend has only a 2-barrel, upgrading to a 4 barrel would be the recommended first course of action. followed by a drop in pitch if his friends are also gravity enhanced.

 

[JASinIL2006]

Thanks, Scott.