Mercury tower of power HP question

[OldMercsRule]

Re: Mercury tower of power HP question

Very VERY kool: Arne!!!!

I always got me eye out fer a 1500xs, or a Twister, (like yers MMM...MM...M ), or even a 1250 BP or a Super BP.

I am also am lookin' fer a post 1/1973 15" mid section if I ever find another Carlson corntender 14 foot tunnel, (sold the one I had me 1250 short shaft on), sniff......sniff. I could run me 1977 1500 on it if I find a 15" mid it will fit.

I also really admire the ol' 1350s. Do you know if they had exhaust tuners as the 1250s lacked?????

Thanks fer yer input. JR

 

[OldMercsRule]

Re: Mercury tower of power HP question

I bumped the "Evolution of inline 6" (or some such, [methinks they use six not 6] in the title), on Scream n' Fly so you fellers could easily find the GREAT READ over yonder if yer so inclined.

It is under "Outboard and Racing History" section or some such over younder.

JR

 

[Droll]

Re: Mercury tower of power HP question

I also really admire the ol' 1350s. Do you know if they had exhaust tuners as the 1250s lacked?????

No real tuner until the 1972 Merc1400

It is under "Outboard and Racing History" section or some such over younder.

JR

While you're over there you might want to take a look at my SSM cutaway too ( sticky at the top in the same section .) , nice engineering by Mercury .

I am also am lookin' fer a post 1/1973 15" mid section

Me too , , well at least the housings as I got the rest of the parts...

Arne Kjetil

 

[OldMercsRule]

Re: Mercury tower of power HP question

Very kool cutaway of the speedmaster Arnie.

When I have more time I will read Mark75H's whole thread n' learn a few things.

Thanks fer sharin'. JR

 

[Chinewalker]

Re: Mercury tower of power HP question

One other thing with the "rating" of motors. There is a built in fudge factor in the rating system that accommodates variations from motor to motor. Take any two motors off the assembly line and hook them up to a dyno, and it is unlikely that they'll put out the exact same power.

With that in mind, the 140 may have actually been putting out 136. When re-rated to 115, maybe it was actually putting out 119, for a difference of only 17 horses, which is a lot closer to the 5-10% loss in the drivetrain PLUS the 10% variance allowed by the ratings.

It's also possible the 140 and 115 were rated at different RPMs, which may blur things even more. As Elmer Carl noted in his old literature, "Horsepower varies with RPM"....

 

[Droll]

Re: Mercury tower of power HP question

It's also possible the 140 and 115 were rated at different RPMs, which may blur things even more. As Elmer Carl noted in his old literature, "Horsepower varies with RPM"....

Good point ...

• Early 115 and the later 90 hp got 5000 > 5500 as max WOT ( no power above 5500 because of the small ports )
• Early 150/140 + the later 115 got 5800 as max WOT
• Merc1500XS got 6300 as max WOT (155 hp at crank )
• Those T2 and T2x racing engines got 7200 as max WOT ( 180+ hp at the crank )

Got at scan out of an old Land & Sea catalog where they claimed 130 hp at 5300 rpm ( dyno ?) at the prop for the later 115hp engine ( and 160hp at 6900 rpm with NOS )...

 

[madgadget]

Re: Mercury tower of power HP question

Just wanted to say thanks for the info in this thread. Its awesome! I have a 79' I6 140 and its answered so much

 

[madgadget]

Re: Mercury tower of power HP question

I have just been looking at that chart. What was done to gain that extra power? And also, is the merc 2.4 EFI the same as the 2.4 V6 XRI?

 

[overtheedge472]

Re: Mercury tower of power HP question

Good stuff in here. I happen to have a 1250 that I was told was taken out to a 1350. I always wondered if when the time to rebuild/freshen up comes can you bore or take this motor out to a 1500?

 

[OldMercsRule]

Re: Mercury tower of power HP question

Good stuff in here. I happen to have a 1250 that I was told was taken out to a 1350. I always wondered if when the time to rebuild/freshen up comes can you bore or take this motor out to a 1500?

The 1250 was a different block then the 1350, (SAME CUBIC INCHES).
The 1500 was also a different block then the 1350, (with the same cubic inches), so: NOPE! JR

 

[Droll]

Re: Mercury tower of power HP question

Good stuff in here. I happen to have a 1250 that I was told was taken out to a 1350. I always wondered if when the time to rebuild/freshen up comes can you bore or take this motor out to a 1500?

The 1250 engine was a crossflow engine, and the 1350 was a "Direct Charge" engine.... those 2 engines are way to different constructions... almost every part are different.

If you got a 1350 block I would think you could make it a "1500", but not without lots of machining ( new portmap, including the later "Power Ports" )+ new pistons, new carbs, new reedblocks... and in the end you still would be missing the exhaust tuning used on the later 150hp engine ...

If you want more power...bye a bigger engine , or give your existing 1250 some TLC and make it as good as it can be...


Arne Kjetil

 

[Texasmark]

Re: Mercury tower of power HP question

Mark,

Are ya sure yer Tower was an 1989? Me thinks 1988 was the last year fer the inline6....... sniff sniff, (I could be wrong), only one functional brain cell.

The "Direct Charge" first came out in cornsumer inline6s in 1970 with the 1350 n' the 1150 silver blocks.

I read somewhere that the 1969 1250 BP has the Direct Charge as well. (Dunno as I have never owned one).

Both me 1968 1250s are the earlier 99.x cubic inch models.

I own a parts 1971 1150 Silver Block n' a sweet fresh water virgin 1972 1150 Silver Block, both say "Direct Charge" on 'em that the 1250s do not say.

Respectfully, JR

It could have been a leftover, but It was sold as an '89 on the paperwork at least, and was on an '89 Ranger Fisherman. I don't remember what was on the ID plate on the clamp bracket, but if it were a leftover, I would surely have noticed it (I pay attention to those kinds of things) and would have brought it to the attention of the dealer which I didn't.

Thanks,

Mark

 

[Pound puppy]

Bringing back an old one here boys. But I am in discussion with a few gents about a motor I have and one that I am planning on going to. I have a 1986 merc 115 inline 6 and I am looking to change the power head to a 150 but I have been told that I am wasting my time as the 115 will produce the same power. Can anyone offer any words of wisdom here?

 

[wired247]

Generally considered bad form to drag up 5 year old threads. This one has a lot of bad info in it as well. Mercury L6's were crank rated until 1981. The 140 which was the rebadged 150 got rebadged again in 1982 to 115 HP. The old 115 became the post '81 90HP.

The primary difference between the old ( 70's) 115 and the old (70's) 150 besides some different carburetor calibration and a slightly different reed cage was the indents in the cylinder walls that worked with cutouts in the pistons to create somewhat of a looper effect. Some people claim the old 150's were downrated from Mercury but I don't believe a word of it. 155 HP MAYBE on a good day. Ive had 140's johnyrudes ( also crank rated ) that would smoke a stout 150 Merc L6 on the same boat ( mine. Had several incarnations of each ) . In any case as stated on your other thread, the 115 you have and the 150 distributor L6 you also have are internally almost the same motor with the 115 having a vastly superior ignition system and just slightly lower compression.

 

[GA_Boater]

Bringing back an old one here boys. But I am in discussion with a few gents about a motor I have and one that I am planning on going to. I have a 1986 merc 115 inline 6 and I am looking to change the power head to a 150 but I have been told that I am wasting my time as the 115 will produce the same power. Can anyone offer any words of wisdom here?

Words of wisdom for you. Do not open old topics! Nine years old, for crying out loud! Please read the rules and the warning on the top of every forum page.

 

[Tex51]

I have a 1978 1150 and know little about it but this reading has giving my brain a work out. I am going to find that Mercury web site and maybe give myself a short circuit. Y'all have the knowledge.

 

[GA_Boater]

Tried to keep it open, but no use.