change engine from chevy to ford

Shorty said:
The reason for wanting more HP is this Boat has always been under powered. And the ECM is bad on the chevy and I can't find an ECM for less than $1500. And I am not willing to spend that kind of money on the chance that will fix the problem.
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I can pretty much guarantee that this swap will cost you more than replacing that $1500 ecm.
 
CliffA said:
have you tried a lower pitch prop on the 240?.....does it have trim tabs?.....both of these things can make a real noticeable improvement in the performance of a boat as far as getting up on plane quicker and easier....

cliff
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I have a 17 on it now but it has no power at all.
 
NorCal Boater said:
Yet another case ill

the highest HP 5.8 makes is 300 HP. I doubt that engine is the 300HP model. there were only a few made. the Alpha drive is good to about 300 HP.

shorty, what you are thinking about doing is a really bad idea. You came on the site asking for advice. You've gotten plenty of it....but not what you wanted to hear. Go ahead and do it but have the nads to come back and tell us about all the problems and costs you've experienced.

What I said earlier comes from 50 years of boating and 10+ years on this forum. The most cost effective way to make a boat go faster is to buy a faster boat.
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I am not trying to go faster I am just trying to get to run right. I have no power and it will not even go much over Idle rpm.
 
Shorty,

In post #23 you say you're not trying to go faster, you just want the boat to run right. But in post #17 you make the statement below stating the boat was always under-powered. So you are really saying 2 things. Which is it?
Shorty said:
The reason for wanting more HP is this Boat has always been under powered. And the ECM is bad on the chevy and I can't find an ECM for less than $1500. And I am not willing to spend that kind of money on the chance that will fix the problem
Click to expand...

The 305 motor should have never been put in that boat. But, Sea Ray and other manufacturers want to sell boats so they take a popular, entry-level, pocket cruiser and offer it with little frills and a smaller, cheaper engine so that they can reduce the price barrier and everybody can buy one. So you bought this boat, for whatever reason, and you either did, or did not sea trial (test ride) the boat. I'm also wondering if you had it professionally surveyed. If you did sea trial the boat it either was (A) under-powered but in the excitement of getting the boat you felt you could live with it; (B) never noticed the sluggish performance or (C) felt it was under-powered but it was a smokin' deal and bought it anyway. I would like to ask you a few questions....

  1. The boat is a '98. How long have you owned it?
  2. Have you always felt it was under-powered?
  3. You state the ECM is bad but don't want to invest $1500 on the chance the ECM won't fix the problem. How do you know it's the ECM? Has the engine been diagnosed by a certified Mercury Technician?
  4. How much are you willing to spend to go faster? Because going faster always costs money. And as most people rarely run their boats at wide open throttle for long periods of time I'm going to go out on a limb and assume by wanting more power you are wanting to get on plane faster.
You have several options to fix the 2 issues you state you are having with your boat but before I get to that I want to say something to you. Mercury Marine/Mercruiser is a really big company with a lot of engineers and technicians. If they felt the Ford 5.8 liter motor was a good choice to connect to their outdrives there would be a shitload of them out there with parts readily available to do the swap....there isn't. The motor coming out of your brother's boat is most likely NOT a Mercury unit but rather a PCM, Crusader or some other after-market engine marinizer. What type and size boat is he taking that motor out of to spend $50,000 on installing a Cummins?

So you do have a few choices....
  1. Ignore all the advice you've been given here from guys who collectively have hundreds of years of boating experience, and install, or attempt to install, the Ford motor
  2. Take your boat to someone that can give you a definitive diagnosis of the problem with your current engine and if it is the ECM you can then (a) fix the motor which doesn't solve your problem of needing more power but it would be the cheapest fix, (b) attempt the Ford install or (c) sell the Ford on Craigslist for a couple thousand and buy a reman GM 5.7 long block and install that.
  3. Pass on the Ford motor and buy the reman GM long block and install it. Many of the parts needed for the 5.7 will work from your 5.0. (distributor, carb & intake manifold [if you have a 4-barrel], exhaust manifolds, risers elbows, motor mounts, flywheel, coupler, water pump, power steering pump, all brackets, etc. You could also get a few bucks for the 5.0 carcass.
  4. Sell the boat and find one with the motor already in it that makes the power and speed that you want. Maybe a good time to go to a larger 260 or 280.
  5. Go all out with a brand new 350 Magnum or a 6.2. Either will fit but you may need a different gear ratio in the outdrive
I may have forgotten a few things but I think I got most of them. But remember, you came on this site and asked for advice on an engine swap. I believe only one response said to give it a go. Generally, the members of this site enjoy helping other boaters and most of us have enough collective experience to tell someone when something they are attempting is not a good solution.

My best recommendations for you are in red above. These are also the cheapest solution in the big picture and #2.c and #3 will give you the greatest return for the least investment.

Good luck on whatever you do. Curious to hear what you decide.

Shawn
 
Makes my point. It is not a Merc. Best of luck to you. You have a decision to make.
 
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