Ditching old 470. Who's done it with a 3.0L?

[SalmonBonker]

Hi all-

Curious if anyone has replaced their 470 with a 3.0L.

I'm running a 1989/90-ish 3.7L/165hp on an Alpha One drive.

The old girl is starting to nickel and dime me and the 3.0L looks like a good option.

Power on the 3.7L (165hp) is sufficient. Cruises at 28-30 mph at 3500-4000 rpm (RPM not positive. never write this stuff down). There's power to spare, but I don't push the old engine.

If 3.0 will cruise at 28-30, I'll be satisfied.

Boat is a 1990 Bluewater Executive Overnighter. Currently about 3000 lbs with engine.

Has an Alpha One Drive.

Serial Numbers
Alpha One : 0D452690
Transom Unit: 0D415834
Engine: 0C767396

Thanks for any tips/experience you want to share.

Mike

 

[stonyloam]

The outdrive gear ratio is going to be wrong for a 3.0, unless you change the gear ratio you may be disappointed with the performance. It might wind up being more cost in time and money than rebuilding the 470. The logical replacement for the 470 is a 4.3 l, same outdrive, and a little more power.

 

[thumpar]

The outdrive gear ratio is going to be wrong for a 3.0, unless you change the gear ratio you may be disappointed with the performance. It might wind up being more cost in time and money than rebuilding the 470. The logical replacement for the 470 is a 4.3 l, same outdrive, and a little more power.

Those are my thoughts also. The 3.0l is going to be down on power. Since you are doing a swap anyway just go to the 4.3l. You can even find them at junk yards. Swap the core plugs and mount it up.

 

[achris]

Those are my thoughts also. The 3.0l is going to be down on power. Since you are doing a swap anyway just go to the 4.3l. You can even find them at junk yards. Swap the core plugs and mount it up.

And the head gaskets and the water pump. And all the electrical parts (starter motor, alternator, distributor), and the fuel system parts (fuel pump, carburettor)... You'll also need a brass thermostat, of 160 degrees, not 180 (as a car/truck would use)...

But yes, I totally agree, you'll be pushing a 3 litre far too hard... You'll be seriously disappointed with performance, and you'll likely use more fuel.

Chris............

 

[stonyloam]

Just curious, what sort of problems are you having?

 

[thumpar]

And the head gaskets and the water pump. And all the electrical parts (starter motor, alternator, distributor), and the fuel system parts (fuel pump, carburettor)... You'll also need a brass thermostat, of 160 degrees, not 180 (as a car/truck would use)...

But yes, I totally agree, you'll be pushing a 3 litre far too hard... You'll be seriously disappointed with performance, and you'll likely use more fuel.

Chris............

You are right. When I think of a swap like this I usually only think of the block.

 

[Bondo]

. The logical replacement for the 470 is a 4.3 l, same outdrive, and a little more power.

Ayuh,..... Agreed,..... The economical solution is buyin' a rotten boat, with a runnin' 4.3l in it, to get All the parts, cheap,....