1997 Rinker 4.3l Mercruiser Alpha 1 - Repower with 1980's 898 Merc 305

[cfullercaptiva192]

I have a 1997 Rinker Captiva 19.2 with a 4.3l Mercruiser Alpha 1 outdrive, I have found a good deal on a 1980's Merc 898, 4 barrel carb, thunderbolt ignition with low hours. I was wondering what complications I would run into if I decide to repower with this engine, or if its even possible.
Thanks

 

[achris]

1980s. Exactly when? The flywheel housing was changed in 1982.

The other thing. I swapped a 4.3LX into a 23' boat. It had a 230hp, 305 in. Boat's now 7 knots quicker.

 

[Scott Danforth]

I wouldnt step backwards like that. the 1997 4.3 probably makes as much power as the early 80's 5.7. the 4.3 is prop rated, and most likely has at least 250-260hp at the crank. the early 80's V8 is crank rated and has 250hp at the crank. so other than going way backwards in motor technology and adding two cylinders. what do you hope to gain?

 

[cfullercaptiva192]

I forgot to mention that my 4.3l engine is toast. I have it set in stone that I am going with a V8 and through hull exhaust. My 4.3l was rated at 190HP and the 898 305 is rated at 198 horsepower. So its not really going to gain me anything, I shouldn't have used the word "repower" in my original post. For the price of this 898, I can't pass it up. I'm balling on a budget here. $1,500 for a complete drop in ready 898. I believe the 898 is post 1982. will it bolt right up? or will I need to do more work than its worth?

 

[Scott Danforth]

$1500 is a high price for a $400 motor that will need new manifolds, risers and other items to be installed

The 898 (305)is crank rated and the 198 is all you got, the 4.3 is prop rated, so add 40hp to the 190 to get crank hp.

You would be better off with a replacement 4.3 an 4 barrel. If you go V8, you will need to regear the drive. Then again, if you went V8, why go with a small valve 305 with smog heads vs a 350 with vortec heads

 

[cfullercaptiva192]

I did come across this deal. It would take 100% of my budget though

 

[Scott Danforth]

that is still a step backwards with the '88 motor.

I would approach your boat in a different way. basically two steps. back on the water in the best possible time while setting a foundation for performance. adding the performance.

I would pick up a 1998-2003 S-10 V6 from a you-pull-it like LKQ for $350. Strip it down to a short block, sell all the parts off the motor on craigslist to get $300 back in your pocket), build it back up with brass core plugs and marine head gaskets, go with a slightly better cam than what is in your 4.3, and a 4-barrel intake. drop that into your existing engine compartment use your existing drive and go with a 4-barrel intake and manifold and go with a set of eddie marine manifolds and long elbows. instant 230-240hp at the prop

you can get the motor back in and the boat running in a few days for about $600 (less if you sell any of the take-off parts) . for the intake and carb (about $700) can come later as well as the exhaust (about 1000)

under your budget, fits the boat, etc.

if your dead set at going to look for drop in motors and drive, stick with 1996 and newer. that gets you the vortec heads (1996 and later) and gets you the Alpha 2 (1992 and later). plenty of late 90's boats that are showing up with rotten hulls that you can get on Craigslist for well under your budget, pull the motor and drive, sell off parts like windshields, etc then scrap the hull and sell the trailer and your current drive.

if you build a 350 to drop in, your looking at a $150 core long block from a you-pull-it and about $1500 to get you a fresh motor (with a complete new rotating assembly). you can part out your 4.3, keeping the front accessories, mounts, flywheel and the starter. transfer to the 350. then all you need is the correct distributor and new exhaust and a set of gears for your current drive. stock exhaust manifolds and elbows will be about $500. under your budget and motor is new. however this will take a few months to be back on the water. This route costs the same if you build a 350 or 383 as the SCAT rotating assembly is $850 either way

a new long-block 350 for 1996/newer applications is only $2k https://www.summitracing.com/parts/nal-12530282/overview/make/chevrolet (There are cheaper places, sometimes including your local GM dealer)