Difference between 5.0 and 5.7?

[Thumbtack]

ive got a v-8 gm merc freshwater cooled. std rotation. tranny. I am going to replace it but am not sure if it is a 5.7L or 5.0L or if it even matters. I know the horsepower is dirrerent but is it different physically as far as everything matching up?

 

[Bondo]

Re: Difference between 5.0 and 5.7?

Ayuh,...

Externally,... Nothing....

Internally,... About 45 cubic Inches....

 

[AZSenza]

Re: Difference between 5.0 and 5.7?

In all fairness to GM, the 5.0 (305) is a horrible engine, any time you can replace the long block with a 5.7 (350) its money well spent. There is usually no price difference in parts except 5.7l usually costs less for engine specific parts. The power/weight ratio is better therefore fuel consumption is usually the same or not far off either way. I have turned down a few boats because they had a 5.0l and not the 5.7l. The main factor for the 5.0 was emissions, obviously with less CID there are less emissions.

 

[edjunior]

Re: Difference between 5.0 and 5.7?

In all fairness to GM, the 5.0 (305) is a horrible engine,

Horrible? Can you please clarify that a bit? I have a 5.0 in my 1984 IMP and it runs great and is still in great shape. I'd sure like to know what is so horrible about that!

 

[AZSenza]

Re: Difference between 5.0 and 5.7?

Sorry, its a good engine, just wasn't designed to make power. It has a poor power to weight ratio as compared to its older brother, the 5.7l. IF you have a choice, the 5.7 is a better powerplant. You can easily obtain 320hp from a 5.7l, to get that from a 5.0l youll over stress it.
Just my 2 cents...but I'm a gearhead

 

[John_S]

Re: Difference between 5.0 and 5.7?

A late model 305 (1998 and on) would have vortec heads and enough hp and torque in many boats. If replacing, yep, start with a 350.

 

[edjunior]

Re: Difference between 5.0 and 5.7?

Sorry, its a good engine, just wasn't designed to make power. It has a poor power to weight ratio as compared to its older brother, the 5.7l. IF you have a choice, the 5.7 is a better powerplant. You can easily obtain 320hp from a 5.7l, to get that from a 5.0l youll over stress it.
Just my 2 cents...but I'm a gearhead

Okay, I can deal with that. That makes sense. So not a horrible engine, just a big difference in HP/Torque for a small basic difference in engine. I feel better now.

 

[AZSenza]

Re: Difference between 5.0 and 5.7?

My Larson currently has a 250 hp 5.7LXi (Fuel Injected) Im changing to Vortec Heads and higher ratio Roller Rocker arms this winter (along with corresponding intake) It will put me at or past the 320 HP mark. Easy HP. My skiers will thank me for it!

 

[KJSmitty]

Re: Difference between 5.0 and 5.7?

Okay, I can deal with that. That makes sense. So not a horrible engine, just a big difference in HP/Torque for a small basic difference in engine. I feel better now.

Yes, many of us gear heads would not start with a 5.0 as an engine of choice if planning to build for HP etc.. But that has nothing to do with the quality or capabilities of a basic 305.

The fact that it "is" a small block Chevy makes it a great engine for the right application.

My buddy has one in his 7yr old boat and it's been nothing but trouble free ops for him. But he is envious of my 320HP 5.7....

Cheers

 

[betayv]

Re: Difference between 5.0 and 5.7?

I have a 305 and my boat is a 22 feet 1979, I do a good maintenance to my engine and never have any issues.

 

[abj87]

Re: Difference between 5.0 and 5.7?

My Larson currently has a 250 hp 5.7LXi (Fuel Injected) Im changing to Vortec Heads and higher ratio Roller Rocker arms this winter (along with corresponding intake) It will put me at or past the 320 HP mark. Easy HP. My skiers will thank me for it!

i hope your going to re tune the efi system if your going to do that.

 

[Hays00]

Re: Difference between 5.0 and 5.7?

Ok I have searched the forums and this is as close as I can find to the topic of my question. I have a 06 rinker 226 with a Volvo penta 5.0L GXI. It has a cracked block and must be replaced. I want to upgrade to the 5.7L Long block only but what other cost will be associated with the conversion other than the cost of the long block? For example computer upgrades, head upgrades, and so on. I am working on a budget but would really like to upgrade if the cost difference is reasonable as the boat is almost underpowered in my opinion at 270hp. Any idea what the hp would be if I could do just a long block only swap use my heads and CPU and so forth intake? Thanks in advance for your time.

 

[Bondo]

Re: Difference between 5.0 and 5.7?

Ok I have searched the forums and this is as close as I can find to the topic of my question.

Ayuh,.... Welcome Aboard,...
That right there is the reason you've gotta start a new thread of your own, rather than Hy-jackin' this 1...

Short answer is,... No Problem...
For the Long answer,...
Start a thread will all the info possible about your motor, drive, conditions,+ Goals....

 

[Hays00]

Re: Difference between 5.0 and 5.7?

Ayuh,.... Welcome Aboard,...
That right there is the reason you've gotta start a new thread of your own, rather than Hy-jackin' this 1...

Apologies....In the fourms I post this would be a continuation of the current thread. However I am a guest here seeking the wisdom of my peers. Thank you for your suggestions.