I posted this on another forum and someone said I’d get more info here. If I were to repower my 22ft Anderson which has an old Kodiak Marine carbed 350 in it and replace that engine with a mercruiser 383 MPI what can I expect to change performance wise? I will be keeping the older Volvo Penta 290sp outdrive since I just rebuilt it. Cruise speed, top speed, fuel economy? Thanks for any input.

Robert

Way to many variables and not enough information.

Yeah, I understand. I just wanted general information about performance differences, if possible, if all I did was swap engines and nothing else.

Robert

As stated earlier....need more info....

What is your current hp with the stock motor? What pitch prop? What is your current WOT speed?

What model 383 MPI are you looking at and what is its rated hp? The hp difference will tell much of the story.

Taking a very wild swag you might get 3-7 mph gain. Details of hull, hull condition, drive ratio, prop size, weight etc will help narrow down the guidance.

Never hear of Anderson Boats, so looked them up.
https://www.andersoncustomboats.com/anderson22

Since many of us prob never messed with one of those, I would play with these calculators which can sometimes be quite close.

https://www.go-fast.com/Knowledge-ba...eed-calculator

That caluculator works pretty good, but you will have a different problem with the giant airbrake on the deck. Im just guessing, but with a tired 350 you were probably seeing mid 40s? With a fresh 383 your probably close to doubling the hp of a tired 350. Im going to guess mid to upper 50s if you get the prop right.

I have a 10:1 383 that's pretty dialed now. I think you will add 7 to 8 mph.

Interesting boat...had also not heard of or seen one before.

Just to echo the other great comments so that we can help you...what is your current speed at what WOT rpm and what prop? We at least need to know this, as well as more details of your current engine. A "carbed 350" could be anywhere from 210 to 300 hp. That 383 MPI is a 350 hp engine. As others have noted, making a broud assumption and saying you are gaining 100 hp, you could see a 4 - 6 mph increase. One thing for sure is your MPG will be much better, how much exactly is hard to say not knowing your hull characteristics and driving style, etc, but it could be as much as a 20% improvement. Sounds like a great project and you'll have the peace of mind of knowing you have a modern, reliable engine onboard.

Have to wonder the cost difference between EFI and Carb, whether it's worth it.

are you talking going from a tired 250 hp 5.7 to mercs newest 350 hp 383 or something older?