Swapping a Mercruiser Gas Engine 5.0 V8 with Mercruiser Diesel 7.3 V8

[sugars]

Can anyone tell me how difficult this swap would me i want to reuse the same gas transmission and alpha one drive.
The boat is a 24ft Bayline. Also would the engine sizes be same or similar ?

 

[spannerman]

Don't even think about it! I guess you haven't seen a 7.3 V8, its a monster and your boat hasn't the room or the buoyancy for a lump like that, the all up weight with drive is around 700 kg, it won't work with an Alpha drive as it will mince it with its torque, plus the gear ratio will be wrong.
If you really want a diesel a 2.8 4cylinder may fit but it will be heavier than the motor you and have, so it will be slower.

 

[MapisM]

Don't even think about it!

+1.
And on top of all these good technical reasons, the 5.0 is just perfect for a 24' Bayliner.
I'd rather think to get rid of a diesel engine and fit a 5.0 petrol on a boat like that, than the other way round!

 

[Divemaster1]

Echo Spannerman here .... the 7.3 diesel is more or less twice the weight of the 5.0 gas engine ... and the drive will not take the torque of the diesel...

.... and expect big re-modelling of internals, as engine will be longer, wider and taller...

To see how the boat will be loaded with the 7.3L, put three large men (approx 300 Kg) on your aft bench..... then add two more to simulate sitting on the bench...

 

[Elessar]

Can anyone tell me how difficult this swap would me i want to reuse the same gas transmission and alpha one drive.
The boat is a 24ft Bayline. Also would the engine sizes be same or similar ?

what they all said, plus once you've recovered the boat from the bottom you will find the alpha 1 drive will have been destroyed by the torque. It can just take a 1.7l diesel.

 

[sugars]

ok thank you very much guys

 

[Latestarter1]

ok thank you very much guys

Not only was Mercruiser V8 heavy, it was a hopeless engine, poorly marinised which had to be withdrawn from the market due to manufacturer being overwhelmed with warranty claims.

 

[volvopaul]

Not only was Mercruiser V8 heavy, it was a hopeless engine, poorly marinised which had to be withdrawn from the market due to manufacturer being overwhelmed with warranty claims.

Princess fitted two into a princess 380, it was a total disaster!!

 

[No Regrets]

Can anyone tell me how difficult this swap would me i want to reuse the same gas transmission and alpha one drive.
The boat is a 24ft Bayline. Also would the engine sizes be same or similar ?

1/ You are an Arab, and you own several oilfields.

2/ You are mad (I prefer this one...)

3/ You like 'excitement' (read; Bungee jumping with no cord, Abseiling with no crampons or Diving with no tanks)


Either way, I admire the size of your testicles, having punted a 5.7 litre sportboat around on holiday at around 50mph....

 

[Swordfish]

Your Bayliner is probably already stern heavy, so the big diesel V8 will be a disaster. This is what I put in mine:

 

[mil1194]

Thought I'd do a google search for research on the 7.3 and this little gem appeared...

http://www.ybw.com/forums/showthread.php?184248-Just-how-bad-are-the-7-3L-V8-Diesel-Mercruisers

Summed it up pretty well I thought!

Also looked like a heavy/large lump from this...

http://www.youtube.com/watch?v=5jaYU_40vwk

Interesting bit of history and amazing how much 'feel-good' can come from a simple brochure.

http://myitmatters.com/mercruiser.pdf