Evinrude looper

trendsetter240

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Re: Evinrude looper

What's the difference in a 120 looper an a regular 120?

A "looper" uses loop charged induction. The other style is called Crossflow scavenged induction.

There have been many threads that discuss the differences between the two. In general, loopers are the better design of the two. And nearly all carbureted 2-strokes larger than 15hp since around 1985 are loopers. With a few exceptions, the SPL models by evinrude being a good example.

All the new 2-strokes as of 2010 will be direct injected as far as I know.
 

Dhadley

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Re: Evinrude looper

All Evinrude and Johnson 120s are loopers. There isn't a 120 crossflow. Looper and crossflow are engine designs. It has to do with how the incoming fuel charge is introduced into the combustion chamber and how the spent charge is removed. Do a search on "looper" and/or "crossflow" or "looper vs. crossflow" etc and you'l get several nice discussions.
 

Texasmark

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Re: Evinrude looper

All the new 2-strokes as of 2010 will be direct injected as far as I know.

Do you mean "fuel injected"? I say that because back in the 1980's Merc used an induction system that was partially similar to OMC's loopers, but only partially as OMC still had the patent on the process. The system was referred to as "direct charged". Not as good as looping, but better than crossflow from an economy standpoint...had one and it was real sweet on fuel consumption.

I would doubt that they would revert back to that 25 year old technology today with new engines. Fuel injection on the other hand is another matter.

Mark
 

trendsetter240

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Re: Evinrude looper

Do you mean "fuel injected"? I say that because back in the 1980's Merc used an induction system that was partially similar to OMC's loopers, but only partially as OMC still had the patent on the process. The system was referred to as "direct charged". Not as good as looping, but better than crossflow from an economy standpoint...had one and it was real sweet on fuel consumption.

I would doubt that they would revert back to that 25 year old technology today with new engines. Fuel injection on the other hand is another matter.

Mark

You are right, I meant Fuel Injected but specifically Direct Fuel Injection.

DFI 2-strokes have fuel injected directly into the cylinder head. The other mainstream type of fuel injection use on the 4-strokes is Multi-point fuel injection where fuel is injected into the intake manifold before the intake valves.
 

Texasmark

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Re: Evinrude looper

Geez, I am talking with out a ladder to stand on, but heck, talk is cheap....you get what you pay for on here.

Question was about loopers. Having had OMC cross flows ( '72 125 hp V4 and smaller) and looper ('75 70 hp 3 cyl) and Merc Direct Charged (115 I6) and later on Merc looper (current 3 cyl 90 hp) I can truthfully say that Direct Charging or looping saves you a bunch of gas over the cross flow. I can only assume that the fuel injected engines save you an appreciable amount more.....I know my trucks that are FI versus nat-aspired are day and night.

Can't comment on current 4 cycles vs current 2 cycles as to fuel economy. From what I have heard, if you gain any on the 4, you sacrifice the savings with maintenance fees.....but that is just what I have picked up from others herein and I have no personal experience.

On multiport vs throttle body FI, my only experience is with multiport in truck engines, not marine. I did notice that GM cars/trucks, with their throttle body which they used for years, advertised hot dog gas mileage. Whether it was fact or hype, I can't say. Obviously it was cheaper to produce.

Mark
 

trendsetter240

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Re: Evinrude looper

Question was about loopers. Having had OMC cross flows ( '72 125 hp V4 and smaller) and looper ('75 70 hp 3 cyl) and Merc Direct Charged (115 I6) and later on Merc looper (current 3 cyl 90 hp) I can truthfully say that Direct Charging or looping saves you a bunch of gas over the cross flow. I can only assume that the fuel injected engines save you an appreciable amount more.....I know my trucks that are FI versus nat-aspired are day and night.

Yes, you are correct. In fact the numbers I have seen reported for the new DFI 2-strokes are that they are up to 30% more fuel efficient than the loop charged carbureted models.

Can't comment on current 4 cycles vs current 2 cycles as to fuel economy. From what I have heard, if you gain any on the 4, you sacrifice the savings with maintenance fees.....but that is just what I have picked up from others herein and I have no personal experience.

There was a thread here awhile back that posted a link to a 5-way test of the new 50hp motors. Then end result was that the new 4-stroke and DFI 2-strokes were almost identical in fuel economy and performance. Whereas the older carb'd 2-strokes can't even compete.

I'm currently rebuilding a loop charged Evinrude 70hp that will be the power on my boat. Just don't have the cash to buy one of these new DFI's yet.

Cheers!
 

Texasmark

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Re: Evinrude looper

I'm currently rebuilding a loop charged Evinrude 70hp that will be the power on my boat. Just don't have the cash to buy one of these new DFI's yet.

Cheers!

I had one of those, '75. That's the one I had to redo the powerhead to the tune of $1000 20 years ago. Cause was the thermostat started sticking [should have given me a clue but the rig was new to me (somewhat used) at the time] and one day at WOT it froze shut. Well, you wouldn't think it would freeze shut at WOT but it did, or it froze and I just happened to be at WOT when the engine froze and I mean froze up tight. Talk about airbrakes? I don't know where the prop overrun clutch was because this boat stopped from about 40 mph to 0 in it's own length and if it weren't for the wheel and console, I would have been over the bow in the water.

So, don't know what year you have and don't really care. For me, put in a new thermostat. Hopefully the newer models have pop off valves for high speed operation and a temp sensor and warning horn to tell you when you have no cooling water. I don't remember if this had a pee vent or not, but even if it did, it wouldn't necessarily tell you that your block was getting hot; depends upon where the water comes from....block, exhaust water jacket, or thermostat output.

Mark
 

spherret

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Re: Evinrude looper

What's the difference in a 120 looper an a regular 120?

Gawd,I'm so pleased someone else asked that question! Thought I might be 'RobinsonCaruso' not knowing that.

And thanks all for the answers!
spherret.(Newbie!)
 

RogersJetboat454

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Re: Evinrude looper

Gawd,I'm so pleased someone else asked that question! Thought I might be 'RobinsonCaruso' not knowing that.

And thanks all for the answers!
spherret.(Newbie!)

This thread just had it's one year birthday....

From the forum rules;
12. Please do not post to threads that have been inactive for more than 3 months UN-LESS you are the original poster. This is a very active forum and any thread that remains inactive for that long should be considered "dead". It is especially confusing when there is an entirely new question posted to an old thread. This is considered a hijack. Please start a new thread of your own.





Please read the forum rules Spherret..

http://forums.iboats.com/showthread.php?t=397820&p=2667700#post2667700
 

Texasmark

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Dec 20, 2005
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Re: Evinrude looper

What's the difference in a 120 looper an a regular 120?

Much better fuel economy to the point were I will not buy a 2 cycle engine that is not Loop Charged....roughly 2:1 less fuel consumption for the same set of parameters.
 
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