Repower 5.0 liter to 5.7 383 stroker

J

jimandsue60

New Member
Mar 24, 2010
215
Sanibel Island, Florida
Boat Info
2008 Key West 186 CC
Engines
Yamaha 150 4 Stroke
I am preparing to repower my 240 Sundeck. It has a 5.0 MPI in it now with a Bravo 3. I can have a reman 5.7 installed which comes with a 1 year warranty or step up a notch to the 383 Stroker which comes with a 3 year warranty. Has anyone here repowered with the 383? Did you have to change the props?

Thanks
Jim
 
Increasing the HP will mean changing the props to a higher pitch. Without doing that you'll easily over rev the engine. I suppose with proper throttle management you could get by - but you'll need to make sure that EVERYONE who drives the boat knows not to go too fast. You'll obviously gain holeshot with the bigger engine, but w/o changing the props, you won't be taking advantage of the ability to cruise at a lower RPM (fuel savings) and higher top end (not "needed", but it's nice!)

You'll be able to recoup some of your money on the propset purchase when you resell your current set.

There was a guy with in the '99-'04 260DA thread that repowered to a 383 and loved it. You might want to search there and see if you can find it. Offhand, I can't remember his "handle".
 
What made/influenced your decison to re-power?

I have same boat and 700 hours on same engine - should I be getting nervous about a re-power in near future?
 
I have about 750 hours on the original engine (about 10 years old) and have just found that I have 3 low compression cylinders because of valves and corrosion. The risers are coming up on 5 years old. If I start adding up all the pieces parts I start getting close to the price of a new engine. So we have decided to drop in a compete engine package. We do operate 100% in salt water.

Thanks for your input Dennis, I think I have 22 pitch props, I will check it next time it is put in storage.

Jim
 
tcason said:
What made/influenced your decison to re-power?

I have same boat and 700 hours on same engine - should I be getting nervous about a re-power in near future?
Click to expand...

Hours are only a small piece of the puzzle. Condition/maintenance is the key. Compression testing and oil analysis (will need to do a few of them over the course of a season of two) are easy and inexpensive ways to get a "feeling" for the condition.

Jim mentioned some excellent reasons to consider what he is doing. If someone can tear down an engine and rebuild it themselves (regardless of ability, there's also the time factor to consider) then that may change things. But other than that, looking into a replacement is wise choice.
 
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My motor (always fresh water) had more than 2000 hours on it when it finally bought the farm. I mean catastrophic failure. I did milk it for a few seasons with low compression on a couple of cylinders. It finally failed when it ingested a bunch of water via bad flapper valves. Note to self: don't let your flappers go.
 
Your props are probably going to be your smallest problem. Your induction and ecm are not going to be compatible with the larger motors.
 
Lazy Daze said:
Increasing the HP will mean changing the props to a higher pitch. Without doing that you'll easily over rev the engine. I suppose with proper throttle management you could get by - but you'll need to make sure that EVERYONE who drives the boat knows not to go too fast. You'll obviously gain holeshot with the bigger engine, but w/o changing the props, you won't be taking advantage of the ability to cruise at a lower RPM (fuel savings) and higher top end (not "needed", but it's nice!)

You'll be able to recoup some of your money on the propset purchase when you resell your current set.

There was a guy with in the '99-'04 260DA thread that repowered to a 383 and loved it. You might want to search there and see if you can find it. Offhand, I can't remember his "handle".
Click to expand...

Rbyers is the member that repowered his 260DA with the stroker. I don't recall if he had to change the gears in the OD or adjust the props at all, but he was very happy.
 
Nehalennia said:
Rbyers is the member that repowered his 260DA with the stroker. I don't recall if he had to change the gears in the OD or adjust the props at all, but he was very happy.
Click to expand...

Ah, that's it. Thanks, Todd!
 
I just completed my 5.0 to 5.7 (350) repower. I didnt get new props (yet) but am going to have some cup added. I can hit the 5000rpm redline (MPI) without blinking, which is nice. Ill add in some cup to hopefully get that right around 4800 fully loaded. I went with the 350 because of the cost of the long block - I paid $2800 for a mercruiser reman long block with warranty, vs I think $4000 for a 383.
 
mvoellinger said:
I just completed my 5.0 to 5.7 (350) repower. I didnt get new props (yet) but am going to have some cup added. I can hit the 5000rpm redline (MPI) without blinking, which is nice. Ill add in some cup to hopefully get that right around 4800 fully loaded. I went with the 350 because of the cost of the long block - I paid $2800 for a mercruiser reman long block with warranty, vs I think $4000 for a 383.
Click to expand...

If money was not an issue would have gone with the 383 ?
 
I'm right in the middle of a similar conversion. 2100 hours on an 85 350, one soft cylinder that wasn't getting better no matter how much I stared at it. I am going with a 383, but doing all the work (except machining & balancing) myself. I picked up a marinized 92 core motor for $100 which was nearly perfect internally but had been through a fire. Rotating assembly with forged pistons & rods, cast crank etc. was about $850. Machining, gaskets, coupler, bits & pieces will be another 500 or so. I'll do the block clearancing. While I don't have the issues with the ECM, I'll likely have to move up an inch or two in pitch - and I have the alpha limitations to worry about - I may be pushing 300 just with the bottom end work/stock cam & heads. The drive will get babied - but we're not hot rodders anyhow....just wanting a bulletproof longblock I can depend on for years.
 
We happened to make a trip with some friends to Palm Island Marina near Englewood, Fl on thursday. When we were ready to leave this morning there was a small boat show at the marina. I walked out and there it was, a 383 Stroker sitting on a pallet. Pretty sweet! I was incorrect in calling it a 5.7 liter engine, it is actually a 6.3 liter engine. Anyway they are going to send me a quote for the engine and install this coming monday. I expect to make a decision this week and get the install going.

The purchase of this engine does not require me giving them my core engine, does anyone have an idea of what a running engine with 3 cylinders with low compression might be worth?? I could sell it complete or sell it for pieces parts. I am open to suggestions.

Jim
 
I have ordered the 383 stroker it should be delivered 11/28 or 11/29. I am going to wait till the sea trials after the install to see what speed and rpms I get. I was able to sell my current 5.0MPI to someone here in Florida for a bit more than Mercury offered. I will try to post before and after photos as well as performance #'s.

Jim
 
What is the cost to go from the 305 to the 383 with everything? (ECM)

LK
 
I replaced a 350 Magnum with a 383 (full engine) and it was 12.5k (seems to be the going price) fully installed. There was an additional $1500 credit from the sale of the old engine to another party that was brokered by my marina shop. I've been extremely happy with the performance upgrade on the 2006 260 Sundancer (heavy).
 
The engine install is starting today. It is a fine looking engine :)

Jim

8242379862_e36485e2d9_z.jpg
 
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