What would be involved in transplanting a 4.3EFI from an automobile into a boat?

Olde School

Olde School

Well-Known Member
Hello, everyone.

We have a 1994 4.3 V6 with 2 barrel carb rated at 170hp. The motor is still running well but we are looking ahead...
Having looked at the rough costs or podding the boat and buying a suitable outboard, we have abandoned that idea.
Pricing out a new marine V6 looks to be approx $20K!!!

So, what would be involved in pulling the current motor, buying a good used 4.3 V6 with EFI from a wrecked auto, and installing it?
These motors can be had for well under $3K.

Please only answer if you have good information and/or experience with this transplant.
Opinions drive me nuts ;-)

Thanks in advance.

Smiley.
 
Marine blocks and automotive blocks are basically the same. You should have no problem swapping them out physically. Having said that, there are few things you need to be aware of. EFI requires a different fuel pump, lines etc. as well as computer control and its related wiring, whereas your carbureteted engine would use everything you already have. If you are running a raw water cooling system, many of the cooling components will not last long in a salt water environment- frost plugs, water pump impeller, head gaskets come to mind; if freshwater cooled these differences are minimized. The camshaft profiles are quite a bit different for an automotive use compared to a boat use, so you may want to replace the cam and lifters. Of course the starter, ignition system and alternator for the marine application would come from your present engine as they are marine rated and suitably sealed to prevent errent sparks.
A good winter project.
As far as removal and installation and preparation of the new engine, you will need a support at a suitable level to remove both engines and an engine stand to locate the new engine while you transfer parts etc. If you cannot get the engine in or out of the boat , due to lift restrictions, you can rent a truck with a crane from budget or the like. If you would rather pull the engine out in the water you can usually use the crane located at most gov't docks. You need to have the engine ready to lift when you want to use the crane though.
 
Cam shaft, distributor, alternator, starter, valves, carb, oil pan, cooling system and potentially engine rotation. It's not worth it.

You're better off looking at a used rebuilt engine either locally or from rebuilder like Michigan Motorz. They have complete packages for drop in at about $US6500 for the 4.3L or these guys locally: http://vancouver.craigslist.ca/bnc/bod/5012238468.html
 
I have a friend that just pulled one out and wants to sell it leg and all. I will talk to him tomorrow and ask the price. He podded with a 4 stroke 250 zuki.
 
As far as pulling an engine, I would not plan to do it on the water..... you must pull the leg before you can remove the engine!
 
marine engine and auto engine have many different components to them cams are the biggest things

For the price of a new crate or someone rebuilding the one you have be close to same amount
 
i have a 4.3 v6

if you could mod your dog house needs about 4-6" longer and go with the 350 mpi
height and width remain the same
much more power and fit a bravo leg
for not a lot more money......
plus parts and bits are more easy available ...
 
wildthing said:
i have a 4.3 v6

if you could mod your dog house needs about 4-6" longer and go with the 350 mpi
height and width remain the same
much more power and fit a bravo leg
for not a lot more money......
plus parts and bits are more easy available ...
Click to expand...

That's outrageous. How is that conversion not a lot more money? He would have to find a complete bravo drive assy, including the transom components. Poor guy just wants a simple answer and he gets a bunch or random thoughts. The net is not the place for advice, holey crap my pants:(
 
Pretty sure the marine 4.3 is a reverse rotation than most autos. The 4.3 in the awd astro would be the only one that would be easy, as it's reverse rotation. Good luck finding a good condition one of those though.
 
Very hard job. Engine is a bolt in. Have to change generator, starter. But the big problem is the EFI controls. The computer. The sensors in the exhaust can not be installed, so bad mixture. My EFI engine is designed for a boat.
 
Thank you for your replies.
There had to be reasons that people weren't doing this.
Califbill put the nail in the coffin with the exhaust sensor reply.
 
Talked to my friend and he said $4900.00 for 4.3 and whole Volvo leg set up with auto pilot.
 
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