Why are they called Loopers?

[Stitch King]

Need to get up to speed on the OMC Jargon. Where did the name Looper come from?

[outboards4life]

When they first came out OMC called it the LOOP Charged engine.

[flabum1017]

Because they used to loop back to the factory with all the recalls :D

[flabum1017]

OK.... because of the wat the intake port and piston were designed..... they eliminated the funny crown and gave the piston a soft dome crown, also changed the intake prt so the fuel/air mix would "loop" into the cylinder in a more efficient manner.

[Streamin101]

Because they used to loop back to the factory with all the recalls :D
:confused::confused::confused::confused::confused::confused::confused::leaving:

[Raceman]

Looper describes the intake charge from the transfer ports and it IS NOT an OMC term or OMC technology. Two stroke motors from WAY BACK including chain saws, go karts, almost every two stroke motorcycle ever built, etc, etc have been loopers. All V6 Mercs are loopers also, as well as some of the later inline engines. On a crossflow engine, such as the early OMC V6 & V4's and all the early Merc inline engines, the intake ports (transfer ports actually) were ACROSS they cyl from the exhaust and this required a deflector on top of the piston to keep the charge from blowing right on out the exhaust port. On the loopers, the transfer ports are across from each other and at 90 degree angles from the exhaust port, so the incoming charge collides with that from the other side and turn back toward their own direction forming something of a "LOOP". The loopers have either flat top pistons, or slightly domed in some cases. Generally speaking the loop charge design is more efficient than the crossflow technology, but it's easier to build more low end torque with a crossflow.

It's interesting that for years Merc only used crossflow and direct charge designs (direct charge is just a variation of cross flow) while OMC started with some loopers back in the 70's, and maybe even 60's with their 3 cyl engines, which almost always out performed all the 50 cu inch Mercs at the races. When the V6's were introduced in the mid 70's, Merc moved foward with looper technology, while it seemed as though OMC went backwards by making all their new V6's crossflows. Of course OMC went back to the loopers with their V4's and V6's later on, but OMC's initial decision to go with the older crossflow design for their new V6's always baffled me as successful as their 3 cyl loopers had been.

[Stitch King]

Thanks Raceman!

Ken

[FlowMaxx]

Merc moved foward with looper technology, while it seemed as though OMC went backwards by making all their new V6's crossflows. Of course OMC went back to the loopers with their V4's and V6's later on, but OMC's initial decision to go with the older crossflow design for their new V6's always baffled me as successful as their 3 cyl loopers had been.


Seems to me that alot of Mercs were getting spanked by crossflows back in the day :D

Crossflow's were made up until 1998, must have been something right.

It is my understanding that OMC was developing a V6 looper around 1974 and Mercury got wind of it and began to develop their own looper, then, Surprise, the production V6 flow came out in 1976

[Raceman]

Seems to me that alot of Mercs were getting spanked by crossflows back in the day :D

Crossflow's were made up until 1998, must have been something right.

It is my understanding that OMC was developing a V6 looper around 1974 and Mercury got wind of it and began to develop their own looper, then, Surprise, the production V6 flow came out in 1976

Actually the little 122 inch Merc V6 loopers did VERY well against the larger V6 CCC/RS engines of over 140 cu. inches at the races.;)

Merc had the T3 race motor around in complete running prototype form in 1973, so it's not for sure when they started the program, but I was told at the time that Merc never considered the crossflow design for their V6 from the beginning by insiders at the time.

[flabum1017]

Winning races is one thing, but for the longest time the word was if you wanted a motor that lasted, you bought an OMC crossflow, if you wanted a fast motor, you bought the Merc. My dad and his friends always bought OMC's. He had only three motors that I can remember in all the time he was alive.

[FlowMaxx]

Actually the little 122 inch Merc V6 loopers did VERY well against the larger V6 CCC/RS engines of over 140 cu. inches at the races.;)

Merc had the T3 race motor around in complete running prototype form in 1973, so it's not for sure when they started the program, but I was told at the time that Merc never considered the crossflow design for their V6 from the beginning by insiders at the time.

Boy, I wish I owned any of those old race engines now :thumbsup: It is just my opinion, but I seem to recall alot of old black max motors running poorly. I think it took them awhile to get the production motors to run consistantly well.

The problem with the omc V6 loopers is weight. They are too heavy for alot of applications, but they are more efficient and make more hp.

[BarryStrawn]

OMC made the crossflow V6 because they could just stack another pair of cylinders on top of the V4 they had made since the beginning of time. It was less expensive to design, manufacture, inventory parts for, and they didn't have to retrain all the dealership mechanics. Same reason as Chevrolet made a V6 by chopping a pair of cylinders off their V8.

But in the long term, they did a complete redesign and built the "looper" V6.

Just too bad they didn't make it by chopping a pair of cylinders off the the race V8.