4.3 engine swap

[netting one]

My buddy has a 84 merc 4.3 185hp merc alpha one motor that is froze up and trashed. He has a 91- 4.3 merc alpha one 205 hp to replace it. One has points and the other electronic ignition, is there any other surprises i should look out for? My plan was just to swap out the engine and leave the rest alone. Maybe save the outdrive for a spare or something. Just though id ask be fore we get started. I read alot of stuff about the 4.3 but didnt see much on the swaps. thanks dan

 

[Don S]

Re: 4.3 engine swap

The 84 185 V6 with points ignition was the 229 cu in 3.8L engine, so you need to use all the 4.3L not just the block.

The first 4.3 used by Mercruiser was 85 with electronic ignition.

 

[RobOp]

Re: 4.3 engine swap

Will an Alpha One generation I outdrive bolt up with the same transom holes for a Alpha One geveration II?

 

[Bondo]

Re: 4.3 engine swap

is there any other surprises i should look out for?

Ayuh,... I'm sure it ain't the only thing,...
But,...
The flywheel cover is Very different as well...

 

[netting one]

Re: 4.3 engine swap

No i was just going to use the complete engine, i wasnt sure on the coupler, flywheel housing those things. I wanted to leave the transom asembly alone and just use the complete engine.

 

[Bondo]

Re: 4.3 engine swap

Ayuh,... Seein's 91 is a change over year,...

Was this new motor paired to an Alpha 1, or a Gen.II,..??

A Gen.II will have a different T-stat housing...

 

[Howard Sterndrive]

Re: 4.3 engine swap

the original flywheel cover and rear mount assembly from the original 1984 3.8 should bolt up to any 4.3 right up to 2000's, so if there's a compatibility issue there, can just use the old cover on the 4.3.

Will an Alpha One generation I outdrive bolt up with the same transom holes for a Alpha One geveration II?

not sure what you mean by transom holes, but the two generations of drive to not mount to each other's bellhousing/gimbal assembly