I’ve heard a few different opinions about putting a stroker motor in a boat. For the people who’ve had experience with marine engines, what are your thoughts…stroke or no stroke?
I want an engine that will last and obvisouly be reliable. So extreme modification is out of the question. However, since the engine has to be rebuilt, I want the best bang for the buck. The block is currently .030" over, and will probably need to go .040" due to wall clearance.
Option is to go the same displacement (355) or increase stroke for 385. For the stroker rod, it has been recomended to use the 5.7" over the 6.0" due to oil ring position.
The main question is will a stroked motor last in a boat? or keep it “stock”
use the longer 6" rod, not the 5.7 rod in a stroker, alway been told to never use a short rod in strokers because u’ll get alot more pressure on the cyl. wall and end up breaking stuff. 6" rod is alot more reliable.
Idk about cubic inch. Its always been a rule of thumb with cars that small block strokers are hotter because of the torque you gain. I dont believe you will see much HP gain when comparing a 355 vs 383, u’ll generally see about 50 ft-lbs more torque tho. But thats becuase your pushing a 3k pound car, idk how that applies to boats. Can’t take that much torque to spin a little propeller. If you want reliabliity i’d build a 355 and slap a weiand 177 on it with a single carb, +1 for cool factor
by making more power, I will need to re-prop it, that I agree. The prop will ultimately determine the engine redline, which i think 5000-5500 is a good target. My thoughts are the added tq would be especially beneficial to a marine application because most its life is going to be in the 2500-3500 rpm range. If properly built, I don’t see why a marine 383 would not be just as reliable as 355.
I also would rather use a 6.0" rod for exactly your reason Mike, less pressure on the cylinder wall. One of the local machine shops recommended against it claiming poor reliability. (which I don’t exactly buy into).
My only concern is on a boat motor you run high RPMs for long periods of time. If you build it with that in mind it shouldn’t be a problem and the extra torque will help you spin a higher pitch prop to keep your WOT RPM’s in a safe range while still giving you enough holeshot to pull up skiers and wake boarders.
I know a decent amount about building boats as I just put almost $10K into my boat this winter.
I went from a 454 to a 496 stroker, and it made a nice difference.
I don’t see why it won’t hold together also because I used quality parts.
But, boat motors do take more of a pounding than car motors. So that needs to be considered when selecting a cam (how high you want to rev to), and choosing your parts.
Also need to consider things such as prop pitch will need to be different when making more power, possibly need a new ignition becuase the stock distributers only usually redline at 5150 RPM, possible need for trim tabs and/or steering upgrades to keep the boat straight and not chine walking, etc. Just like all the extras you need to do when building a fast car, and you know chuck…
the whole story on the engine is that it used to be in a race car before it made it’s way to the baot. I’m 95% it was a lancaster circle track motor. In any case the motor was beat, not to mention the oil was a bit low… Bet On Another Thousand.
The boat is a 21ft Donzi, top speed before this was ~60-62. I don’t need to go much faster, but 65mph on the water won’t be too bad.
i dont know too much about stroker motors, and or boat motors. but my buddy’s dad has a pontoon boat about 24’ i think. well he has 30g into the motor supercharger on it and it’ll do wheelies on the water.
its funny as hell seeing a pontoon boat doing 60 across the water with only about 6’ of it still submerged
hydrostream6 i believe(Adam) he has 8 boats right now lol. Including a f1 tunnel that should do 125ish lol. However ALL of his boats are outboards, not sure how indepth he goes with sbc inboards. But that 100hp adds 5mph seems a little rough but then i guess depends on the size/weght of the boat. He also has the red STS gto, chuck im sure you know him. ADAM if your reading this “TEAM CRACKERJACKS FOR LIFE” MISS YOU MAN!
