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Big Block in later 232 Captivas

Robyw1Robyw1 Member Posts: 56 ✭✭
edited August 2013 in Rinker Sport Boat Forum
Sometime in the near future I want to repower my 2004 Rinker 232 Captiva. I was wondering if anyone ever installed or even seen a big block (496 or 502) in a later generation 232 with the walk-thru transom. Just by looking at the 5.0 MPI that I have now, I wonder if there is enough room for a big block. As it is I do not think I could put a freshwater small block without interference from the back seat rest. I know it would be cost effective to just trade in but I like this boat and have already spent untold amounts of money getting it to my liking. I do not mind spending more, it is a hobby and I enjoy working on it, even though there is nothing wrong with it. I already have all of the DTS components to work with whatever engine I repower with. If a big block won't fit then it is going to be a 6.2. Not looking for a lot of speed, just maybe 55 or so. Right now it tops out at low to mid 40s Any thoughts?

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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    dang big blocks are big.... :-) ... mebbe you can shoe horn it in there, but I'd personally go with a stroked 5.0 or 5.7....

    it's all about the torque, and a longer stroke- whether you bored or just honed the cylinders and notched the block- it would give a LOT more torque by not only providing more volume displacement, but also a longer power stroke..

    fuel delivery has to be addressed with more displacement... everything else can remain relatively the same.. you could expect as much as 75~80 ponies by simply doing that... add in rolling rockers, ported and port-to-gasket matched intake manifold-head-exhaust manifolds, along with some bowl work on the chamber, you can flow as much as 800cc's or so additional flow... it's said that an additional 10cc's flow ~through~ an engine accounts for a pony... that would be 80 more, on top of the 80ish from stroking the engine... 160hp over what, 250~270 now? ruh-roh raggy, you'll be needing brakes on that rig, too.. :-)

    you'd be getting that coveted 55mph below red line with that... it would fit without any argument, too..
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    puttinputtin Member Posts: 14 ✭✭

    Robyw1,


    I have the 6.2 in the exact year you have.  It's a solid 55 mph boat and I've seen 57 at times.  Much better economy that going with a 496 I would imagine.

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    Robs_232Robs_232 Member Posts: 212 ✭✭✭

    I think Michael T put a big block in his 232. You might message him for details.


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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    edited June 2014

    I've had two 232s (older models) with 502s. Those were the also the "older" version of 502s that were no where near as efficient as the new ones. They both had the Rinker factory side through hull silent choice exhaust and WERE fast. IF you really want a 502 some quick measurements would help you. I'm pretty sure Randy or someone at Rinker could tell you if a 502 would fit into your 2004. Remember that you'll need forward room (aft to bow), side to side (starboard to port) and the one everyone seems to forget - top to bottom. I don't think you want to get into a modified swim pad top, so measure carefully. I actually got into my engine compartment and had a friend shut the cover and measured from the inside.  I like Drew's advice. I have used several stroked 5.7s you can easily get 390 very reliable and manageable (around the docks) HP. You might even be able to trade your 5 liter in on a stroked engine. If you are buying an already stroked 5.7 insist on a signed parts list to make sure the money was spread evenly top to bottom on the engine so that one area is not overbuilt. If it is new it should have a warranty. If you are having one built fresh, I recommend going to a known builder and tell him what you want. To do it right, the only "stock" part he will probably use will be the 5.7 block. All the rest - everything - will be new. Remember that you will need a Bravo I drive as a stroked 5.7 will twist an Alpha I . You will also need an engine driven sea water pump. No big deal. You can also find good used stroked engines - if you can trust the seller. If there are questions in your mind, a compression test, leak-down test and an oil analysis would be prudent. You might also be able to find a nice used 6.2L They are a very robust engine - not at all like a "stock" 350. They have been engineered by Mercury Racing and are  really well-built. IF I was building my own stroked engine "from scratch"  for the difference in $ I would build a 383 for the extra torque. I find the 383s to be real monsters for their size and weight. Please don't be put-off by all my advice. This is a very doable project at a reasonable cost. If you like your boat and you have already put $$$ into it you would be better off (IMO) spending more money on the engine as you already "know" your boat. Trading boats to get a bigger engine could cost a lot more in the end if the boat itself needed work to get it to what you already have! BTW, by going with a stroked 350 you will save a lot of weight over a 502 and your boat will sit a bit higher in the water at the stern end - both helping a lot with pick-up and top-end speed. So 377 or 383 - IMO you couldn't lose with either. I'll see if one of the guys I gave the build sheets to with the boats when I sold them kept them They had all of the part numbers etc. Good luck. Pls keep us posted. MT
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