Going from 5.0mpi to 383mpi, what can I expect?

[Full-throttle]

I have a 2006 Classic 18 that came with a 5.0 and a Bravo 1 with a 1.65 drive.
My engine has 52 hours in is in perfect condition. Figuring about $800.00 for the swap and what I can get from my engine, it looks like it will cost about $5000.00 for the upgrade. I want to stay with fuel injection. Any idea what I could expect to gain over the 5.0? I'm trying decide if the extra expense is worth the real world gains. Thanks...

[VetteLT193]

which 383? If you are talking merc there are a couple flavors with different power. Also, if you are talking the Merc ones I am thinking of, they are Reman engines, not new, so keep that in mind too.

[Full-throttle]

The engine I am looking at is from NuWave Marine in NJ. It is the remanufactured Mercruiser 6.2 with fuel injection and 350HP. $7800.00
My engine is 260HP.

[osur866]

You can expect 67-68 box stock, now if you change exhaust and throw a -2 on it and find the right prop, then 72-73 full hyd steering will help as well. But stock bravo 1 with 1.65 gears that combo with a stock 25p m+ will be 67-68 at 5000 rpm. Some will say it's gonna be a 70 mph boat with that combo and on the dream-O-meter it may show 70 but gps it and it will be 67-68, if you want 70 your gonna have to add some other stuff, been there done it!

Steve

[tice652]

osur866 - I think he will break 70 with this combo. I have a stock 14 year old 350 mag mpi - 300 hp with a bravo and it runs 68.6 gps - either way keep us posted full-throttle im curious about what you'll get.

[Full-throttle]

Thank you, that gives me a good idea. I haven't even run the boat with the 5.0 to see how it performs with that engine. I just bought the boat and had it delivered to the northeast.

[Fishermanjm]

where in the northeast?

[Full-throttle]

The boat is in Connecticut right now. I will be using it around here and also at our summer cottage on Great Pond in the Belgrade lakes area of Maine.

[Fishermanjm]

i'm on narragansett bay,,,

[osur866]

Something that raises suspect is a 5.0 infront of a Bravo, sure it's a Bravo? Think if you dropped the 6./ or 383 mag in with the Alpha he'd be a cpl mph faster and as long as he kept it in the water the Alpha should last.

Don't know what a 5.0 in an 18 would do box stock but just guessing would go with 60-61. Either way the 6.2 or 383 mag is a nice set up and with the forged crank is a good candidate for boost later should it not provide ample speed for you, Whipple makes a nice kit for that engine.

Steve

[The Hedgehog]

I am with OSUR866 on the speed. I have this package in my X-18. I have eeked 70-71 (GPS) or so on that perfect day. That would be cool day with slight chop. It will break 68 every time you drop the hammer. It will NOT break 70 on a hot day, glass, full fuel etc.

[osur866]

osur866 - I think he will break 70 with this combo. I have a stock 14 year old 350 mag mpi - 300 hp with a bravo and it runs 68.6 gps - either way keep us posted full-throttle im curious about what you'll get.

He asked what he can expect, it has been my experience, over 350 hours behind the wheel of my 06' 18, that in fresh water at 960' 2 people and half tank of fuel he can expect 67-68, like Bill said on fumes on a perfect day low humidity yes he may eek out 70 but it won't happen consistently, just saying!

Will we see ya at AOTH Bill?

[Full-throttle]

Thanks for all the responses. It is a Bravo 1. I'm not sure why they ordered that combination unless the original owner thought he might upgrade the power at some point. It does make sense that he went with the 1.65 instead of the 1.5 gears for that engine. In terms of seat of the pants, is there an amazing difference if you took a ride in mine, and then hopped in an 18 with a 383?

[osur866]

Keep the 1.65 gears, will be more challenging to prop but the accelarion will be worth keeping them. I'd say yes, there would be a pretty big difference between a 5.0 Vs a 383mag these 18's stock can get interesting in the upper 60's in the low 60's it's a Sunday afternoon drive! even with a 383 mag hyd steering would be a good consideration

[The Hedgehog]

He asked what he can expect, it has been my experience, over 350 hours behind the wheel of my 06' 18, that in fresh water at 960' 2 people and half tank of fuel he can expect 67-68, like Bill said on fumes on a perfect day low humidity yes he may eek out 70 but it won't happen consistently, just saying!
Will we see ya at AOTH Bill?

Yes, we will be at AOTH?

You? Any surprises? My friends that went to the LOTO shoot out are still talking about the way you drive an 18. These guys were in OL's and Skaters but were very impressed.