Engine Swap 4.3 in place of 3.0 LX

[Brad S]

I have a 3.0LX 1991 engine that probably is going to need to be rebuilt. Will I have a lot problems if I decide to swap for
a 4.3 or a V8.
The boat I have is 19' Marlin Fisherman's Cuddy. Is this a bolt up operation to the out drive assembly or is there more to it than that?
My out drive assembly serial # is 00482302

 

[thumpar]

Re: Engine Swap 4.3 in place of 3.0 LX

It will not just bolt up. The mounts are not right so you will be doing work on the hull. The outdrive will be the wrong ratio also.

 

[Bondo]

Re: Engine Swap 4.3 in place of 3.0 LX

I have a 3.0LX 1991 engine that probably is going to need to be rebuilt. Will I have a lot problems if I decide to swap for
a 4.3 or a V8.
The boat I have is 19' Marlin Fisherman's Cuddy. Is this a bolt up operation to the out drive assembly or is there more to it than that?
My out drive assembly serial # is 00482302

Ayuh,.... thumpar is dead on Right,... You'll also need the proper exhaust y-pipe, castin's, 'n pieces,...

 

[Brad S]

Re: Engine Swap 4.3 in place of 3.0 LX

Sounds like I should rebuild my motor. A little history. We replaced the head because it had a hole in it (and water got into the oil. The motor never overheated). Now it starts up fine and runs at good all the through the throttle range for about 10 minutes and then loses power and dies. It will start again after sitting for about hour and then does the same thing. Now, if you take the oil filler cap off right after it dies, you will see a puff of white steamy/smoke. Was told could have a bad water manifold. I don't know. My compression in the motor is 155 in 1, 155 in 2, 150 in 3, and 155 in 4.
Don't know what to do?

 

[thumpar]

Re: Engine Swap 4.3 in place of 3.0 LX

I don't think you need a rebuild. Time to diagnose.

 

[Brad S]

Re: Engine Swap 4.3 in place of 3.0 LX

What diagnosing should I do and in what order?

 

[thumpar]

Re: Engine Swap 4.3 in place of 3.0 LX

First find out if it is getting spark or not when it won't start after dying. That will tell you if you have a fuel or ignition issue.

 

[Brad S]

Re: Engine Swap 4.3 in place of 3.0 LX

Ok. Will get back with results tomorrow.
Thanks

 

[Bondo]

Re: Engine Swap 4.3 in place of 3.0 LX

Ok. Will get back with results tomorrow.
Thanks

Ayuh,... Yer symptoms stated above, leads me to believe ya might have a Fuel delivery issue,....

Hook a remote fuel tank to the fuel pump fittin', 'n see if it still stalls,...

 

[fishrdan]

Re: Engine Swap 4.3 in place of 3.0 LX

It does sound like fuel delivery. Do as Bondo suggested. There is also a fuel system trouble shooting guide up in the stickies. I'd be tempted to cobble up a fuel pressure gauge to see what the pressure is at the carb during operation, and when the problem occurs.

Now, if you take the oil filler cap off right after it dies, you will see a puff of white steamy/smoke. Was told could have a bad water manifold.

Pull the plugs and see if any of them have rusty tips, of if they look perfectly clean like they were "steam cleaned". You could also pull the manifold to see if the passages are rusty, then fill the manifold's water jacket with acetone to see if it has any cracks/leaks. (Acetone will seep through cracks that water won't seep through.)