Old Merc. 3.0L not 140hp?

[bill 22]

Re: Old Merc. 3.0L not 140hp?

Yes, I would agree it has been a lot of fuss over a 30 yr old 4 banger. I got my answer in the 2 & 3[SUP]th[/SUP] post.

I like a good sidetrack but this prop talk did go a while. I have been following along just to see if I could learn more about this engine. I know this whole prop discussion has nothing to do with how much hp an engine makes. Changing props just changes how you use the hp you have (holeshot vs top-end). I agree with those that say keep your wot in the manufacture recommended range.

I would not say I was ?stressing? over this engine. I just want to get all I can out of it and this is the place to ask questions. It has been said several times and I think it is good advice, ?that?s what you got an old 3.0L, run it and have fun.?

bill

 

[achris]

Re: Old Merc. 3.0L not 140hp?

I know, just saying exactly what the book says. I know 4.3l = 262cu

View attachment 132334

That looks like a seloc or clymer... My genuine manual shows '181 CID (3.0L)'....

 

[sweet addiction]

Re: Old Merc. 3.0L not 140hp?

That looks like a seloc or clymer... My genuine manual shows '181 CID (3.0L)'....

Nope, It is a genuine Mercruiser owners manual printed in 1993

 

[Don S]

Re: Old Merc. 3.0L not 140hp?

Owners manuals were noted for misprints. They don't get updated like service manuals do. Even the OEM service manuals have mistakes in them. Dealers get changes and updates for service manuals, not something that happens with owners manuals.
Oh, and the 3.0LX had a different head on it than the 3.0L

 

[LilRedNeckGirl]

Re: Old Merc. 3.0L not 140hp?

Oh cool beans, now we can argue the displacment of the 3.0 181 and who has the correct owners and service books.... LMAO.... Let the debate begin...

 

[Don S]

Re: Old Merc. 3.0L not 140hp?

Oh cool beans, now we can argue the displacment of the 3.0 181 and who has the correct owners and service books.... LMAO.... Let the debate begin...

There is no debate about it. Only one person here thinks 181 cu. in. is 4.3L. Simple math cures that problem.

 

[lonemust]

Re: Old Merc. 3.0L not 140hp?

to solve the issue of the hp. a dealer had told me last year that my boat was rated at the flywheel. the newer boats are rated at the prop. Some of the differences are in the tuning of the engine.. Bill i too have an "old" 140 hp 3.o. mine is in a 1970 starcraft v-180, its the factory engine and outdrive.. I just found out the 14.5 x 23 is to big of a prop for mine. But then again it is up in the operating range when cruising. I do have a holeshot issue with it, but Im fixing to put smart tabs on my to help it out.. there is other issues other then the prop as to why im going with them.. It likes to chine walk, porpoise, and excessive bow rise..
EFI on an engine can make a big difference on the horsepower over a carb. as for not getting an more power out of a 4 cyl, not so. a good machine shop can get over 20hp more out of the engine if you want to spend the money.. It takes some boring.port and polishing and a different cam.. the better the engine breathes the better the power.

 

[achris]

Re: Old Merc. 3.0L not 140hp?

to solve the issue of the hp. a dealer had told me last year that my boat was rated at the flywheel. the newer boats are rated at the prop.

And in 2003 Merc went back to rating at the crank.... (to meet California emission rules.)

Some of the differences are in the tuning of the engine.. Bill i too have an "old" 140 hp 3.o. mine is in a 1970 starcraft v-180, its the factory engine and outdrive.. I just found out the 14.5 x 23 is to big of a prop for mine. But then again it is up in the operating range when cruising. I do have a holeshot issue with it, but Im fixing to put smart tabs on my to help it out.. there is other issues other then the prop as to why im going with them.. It likes to chine walk, porpoise, and excessive bow rise..

Try a ventilated prop (Laser II or high five)

EFI on an engine can make a big difference on the horsepower over a carb. as for not getting an more power out of a 4 cyl, not so. a good machine shop can get over 20hp more out of the engine if you want to spend the money.. It takes some boring.port and polishing and a different cam.. the better the engine breathes the better the power.

When Merc first put EFI on the 3 litre they increased the output, only to find that the bottom end on those engines can't handle it. About 150hp (crankshaft) is their limit, if you want them to stay together.

Chris......

 

[sweet addiction]

Re: Old Merc. 3.0L not 140hp?

There is no debate about it. Only one person here thinks 181 cu. in. is 4.3L. Simple math cures that problem.

Actually Don S...If you would read all of the posts you would see that not one person thinks that. I suggest you think twice before trying to be mister know it all.

 

[fishrdan]

Re: Old Merc. 3.0L not 140hp?

According to my 1993 Mercruiser owners manual....there is a 3.0L which is rated at 115hp at the prop shaft and then there is the 3.0LX which is rated at 135hp at the prop shaft. Both have the same bore,stoke and compression. The 3.0 has a WOT of 4200 - 4600 rpm. The 3.0LX has a WOT of 4400 - 4800 rpm. The displacement is 4.3 liters/181 c.i.

There is no debate about it. Only one person here thinks 181 cu. in. is 4.3L. Simple math cures that problem.

Actually Don S...If you would read all of the posts you would see that not one person thinks that. I suggest you think twice before trying to be mister know it all.

Am I missing something here...

 

[achris]

Re: Old Merc. 3.0L not 140hp?

According to my 1993 Mercruiser owners manual....there is a 3.0L which is rated at 115hp at the prop shaft and then there is the 3.0LX which is rated at 135hp at the prop shaft. Both have the same bore,stoke and compression. The 3.0 has a WOT of 4200 - 4600 rpm. The 3.0LX has a WOT of 4400 - 4800 rpm. The displacement is 4.3 liters/181 c.i.

Am I missing something here...

Yep, somebody has fingers engaged while brain cell is in neutral....

S.A. - Last time I looked, 1c.i. = 16.3871cc, so 4.3 litres DOES NOT AND NEVER WILL BE 181c.i.
and that is precisely what your post is suggesting. I think you owe Don an apology....

Chris.......

 

[sweet addiction]

Re: Old Merc. 3.0L not 140hp?

Yep, somebody has fingers engaged while brain cell is in neutral....

S.A. - Last time I looked, 1c.i. = 16.3871cc, so 4.3 litres DOES NOT AND NEVER WILL BE 181c.i.
and that is precisely what your post is suggesting. I think you owe Don an apology....

Chris.......

According to my 1993 Mercruiser owners manual.... At what point did I say that Ithink that 4.3l=181c.i.??? See my point? The manual says it...not me! If some of you would actually read you would see that I followed it up by stating that I am well aware that 4.3l = 262c.i. Maybe some of you should apologize for not reading everything and jumping all over someone so that you could attempt to sound smart?