HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

[heebeha]

Does anybody have any insight into what I will need to do/change to swap a Mercruiser 140 3.0 Alpha1 Gen2 with a 140 3.0 Alpha1 Gen1 engine?

I have a 1999 Bayliner 1950 with a Mercruiser 140 3.0 Litre engine. I need to replace it. I found a strong running 1989 Mercruiser 140 3.0 Litre engine that I want to use. I was told I need to check to make sure it will drop in before I buy it. He says the bellhousing and flywheel may not line up, but he's not sure. I am hoping someone here has done the swap and has experience with what snags I may come across.

Any advice would be greatly appreciated.

Thanks in advance.

Jeff

 

[xltier]

Re: HELP: Swapping a 3.0 Alpha 1 Gen2 with a 3.0 Alpha 1 Gen1 Motor

Re: HELP: Swapping a 3.0 Alpha 1 Gen2 with a 3.0 Alpha 1 Gen1 Motor

gen 1 and gen 2 are mostly referring to the outdrive and transom stuff.

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Any idea whether it will bolt in without issues?

I need to know if the flywheels are different, if so can I simply take my old one (1999) and bolt it on the 1989's crank and if the bellhousing is different, will my (1999) bolt on the 1989?

Will the mounts align?

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Im in a real bind here. Any help would be greatly appreciated

 

[Bondo]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Ayuh,... If you have both motors sitting side by side, you'll have enough parts to bolt either 1 in...

 

[mariner1900]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

There are 3 main things to check:
1. Check the centre distance of the rear mounting bolts on the "89" engine and compare to the centre of the '99 engine. Should get 9.5" and if both the same then the '89 engine will sit on the transom plate.

2. Check the exhaust positioning to make sure the '89 will match with the position of the '99 exhaust.

3. Check coupling type on both engines

 

[Fordiesel69]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

I think the flywheel and coupler will just swap over with no issue. I have not read of any balancing issues. The exhaust may be different but if so just swap over the manifold.

 

[Simoniz]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

There are 3 main things to check:
1. Check the centre distance of the rear mounting bolts on the "89" engine and compare to the centre of the '99 engine. Should get 9.5" and if both the same then the '89 engine will sit on the transom plate.

2. Check the exhaust positioning to make sure the '89 will match with the position of the '99 exhaust.

3. Check coupling type on both engines

To the above list, I would add, Check the height from the centre of the crankshaft to the loadbearing faces on the engine mounts - to ensure that you will be able to get the drive to align to the engine.

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Thanks everyone. I am really looking for someone who has done this before. It does not look like the flywheel bolts line up. I matched them and it is off.

Also if I do swap the flywheels somehow, wont it throw off the balance of the crank??

Does anyone have any hands on first hand experience with this?

Must be someone out there.....

Thanks again.

 

[Bondo]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Ayuh,... Why are you swapping flywheels,..??

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

auhhh i dont know

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

I think the flywheel and coupler will just swap over with no issue. I have not read of any balancing issues. The exhaust may be different but if so just swap over the manifold.

Why do i have to swap the flywheel and coupler? My 1990 flywheel will not fit the 1989 crank. The bolts dont match up.

 

[mariner1900]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Your flywheel from the '99 engine probably will not fit the '89 engine. I think the '89 has a 2 piece rear seal and the '99 engine has 1 piece seal therefore flywheels aren't interchangeable.

The '89 engine should be a drop-in.

I am currently fitting a '92 engine into my boat to replace the '74 engine.
I need to fit a modified flywheel so I can use my '74 flywheel housing and starter motor so I can mount the engine as the '74 mount centres (14.5") are different to the '92 mount centres (9.5").

You should be able to just drop the '89 engine in as the rear mount centres should be the same, i.e both 9.5".

 

[heebeha]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

Thanks Mariner. I am going to measure the bellhousings and report back. If its off I can always shim the bellhousing up or shave it a bit if its not to much off.

 

[mariner1900]

Re: HELP: Swapping a Merc 3.0 Alpha 1 Gen2 with a Merc 3.0 Alpha 1 Gen1 Motor

The measurement you need to take is between the centre of one of the rear mount bolt holes to the centre of the bolt hole in the other rear mount. This should be 9.5".