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  OMC v4 vs v6, looper vs crossflow.

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Author Topic:   OMC v4 vs v6, looper vs crossflow.
george nagy posted 03-26-2002 11:11 AM ET (US)   Profile for george nagy   Send Email to george nagy  
I am looking at various whalers powered by older omc engines that sem to have some life left in them.

Some 18'-25' boats are powered by single or twin crossflow v6 150-225 hp omc engines. Others are powered by single loop charged v4 120-140 hp omc engines.

Lets take an 18' outrage as an example. Which engine would be of preferance a 140 v4 looper or a 150 crossflow both being the same vintage?

Keep in mind I am very familiar with the 150 crossflow on my 18'and understand that I might not notice the 10 hp drop but intstead might enjoy the better fuel consumption.

I would like to here some your opinions as to the pros and cons of each.

Bigshot posted 03-26-2002 02:48 PM ET (US)     Profile for Bigshot  Send Email to Bigshot     
On that or any boat where I can get close to max hp and drop 2 cyls I will take the 140 any day. Yes the 150 will be faster and have a better holeshot but in reality, where do you do most of your driving? Same goes for a 17' I would take a 3cyl over the 4cyl if waterskiing was not a big priority. I just put a 25hp on a 13' fast enough for me and most people.
Peter posted 03-26-2002 06:05 PM ET (US)     Profile for Peter  Send Email to Peter     

I've heard that the 140 looper is actually a bit faster than the 150 cross-flow on the 18 Outrage. Don't know whether that's true, but that's what I've heard.

However, one theoretical advantage of the 150 is that at any given speed the 2.6 liter 150 shouldn't be working as hard as the 2.0 liter 140. Everything else being equal, "there's no replacement for displacement."

Bigshot posted 03-27-2002 10:17 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
True true true but.....find me a big block chevy that burns less gas than a SBC.

With any boat, efficiency is what I care about. Believe it or not though, my 24' Baja with a 400+hp BBC gets better mpg(1/2mpg) than my 20' Hydra-Sport w/225 looper. 1/2 don't seem like much but the difference between 3mpg and 2.5mpg adds up.

peteinsf posted 03-27-2002 04:27 PM ET (US)     Profile for peteinsf    
Just to be clear the 120-140, 200-225 are loop charged the 150-175 and 235 are cross flow.

The loop charged motors will get better MPG due to more complete buring of the fuel.


Bigshot posted 03-28-2002 11:09 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Nope! Depends on what year depends on whether or not a looper. All 120's are and 140 bigblocks. They also have v6 gear cases. The 140 also came in a crossflow. All 225 are loopers I believe and the smaller 60 degree 150 & 175's are loopers. 200's can be either a cross or a looper. I think 1987 they went to looper blocks on OMC v6's to keep up with Yamaha.
Peter posted 03-28-2002 07:17 PM ET (US)     Profile for Peter  Send Email to Peter     
BS, it was before '87 because I had a 1986 2.7 liter looper 225 on my Revenge. I believe that the 150 and 175 went to the new looper 60 degree block in '91. Before that they were the old cross-flow.
peteinsf posted 03-29-2002 08:56 AM ET (US)     Profile for peteinsf    
Bigshot thanks for the clarification; my knowledge is limited to '80s info. I do recall the V6 loopers before '87. The 2.7L became 3.0L in 1988, but I don't know when the 2.7L loop charged first arrived, maybe 1985.

A note on the 120 and 140, in 1986 they switched to the V4 gearcase. I ordered a 1986 motor (looking at a big 1985 in the showroom) and when it arrived it had a 90HP lower end. I ended up putting a '85 commercial 100 lower end on it which also was a V6 case.

Bigshot posted 04-01-2002 10:27 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
I guess 86 was the year because they still made the 185 & 235 in 85 and they were cross'. My neighbor has a 87 140 and it has the V6 gearcase.
Tom W Clark posted 04-01-2002 10:54 AM ET (US)     Profile for Tom W Clark  Send Email to Tom W Clark     
Pete & BS,

A note on the gearcases for the 120 and 140 of that era (these motors had blocks which were essentially half of the V-8 which was in production then.) I had a friend with a 1988 Outrage 18 with a Johnson 140. It had the big (V-6) gearcase. My memory is a bit fuzzy, but I though the 140 had the big gearcase, but the 120 had the V-4 gearcase.

Pete, was the motor you orderd a 120?

peteinsf posted 04-09-2002 02:23 AM ET (US)     Profile for peteinsf    

I am sure it was a 140, as a additional bit of info, I just received a "looper" service manual that covers the 1988 120-140 125-Commerical 200-225 and the V8s. In that there three gear cases used on loop charged motors.

Small 105mm x 465mm "V4"=120TL-TX 140TL
Med 117mm x 487mm "V6"=125,140TX,140CX all V6s
Large 130mm x 506mm "V8"=all V8s

If it's the same as 1986 I bought a 140TL. I suspect the 1985 140TL may have had a V6 case. The manual identifies the cases as "V4" "V6" and "V8" and will refer you to the V6 section if you have a V4 140. I guess the never envisioned a 140HP V4 in the "old days"

Bigshot posted 04-09-2002 11:16 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
Nah! They had v4 135's in 1973 and went to a 140 in 1977. They used to give you a SS prop as standard equip on the 140's to entice you away from the 150's or 115's I guess. never understood why?
lhg posted 04-09-2002 02:26 PM ET (US)     Profile for lhg    
Mercury's 60 degree V-6's, introduced about 6 months after OMC's V-6's, were all loop charged from day one, in 1976. I had always assumed the OMC V-6's were also loop charged, like their 3 cylinder model. I believe the 3 cylinder OMC 55-70 was the first loop charged engine brought to market, and before the Mercury V-6.
Bigshot posted 04-10-2002 10:27 AM ET (US)     Profile for Bigshot  Send Email to Bigshot     
The 55hp 3cyl looper was 1968. They then did the 50hp 2cyl Lark looper in 71. It was not until the 80's when another looper was made. I am still amazed at why the new 35hp in 76 was cross-flow and the v-6's in 76 were cross as well.
Peter posted 04-10-2002 06:53 PM ET (US)     Profile for Peter  Send Email to Peter     
Could it be a lack of low end grunt. It has always been my opinion that the 2 and 3 cylinder OMC loopers lacked some real low end torque. Seemed like they needed some revs before they really got going.

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