TOPIC: loopers

First of all why are V4 OMC motors called loopers?
second of all:
I have an 80 HP V4 2 stroke OMC inboard. ....how interchangeable is it to the powerhead from an outboard? like a 90 or 115?

forums.iboats.com/.../non-repair-outboard-discussions/378573-evinrude-looper

Jan 16, 2012 · 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.

Ok. Thanks for the answer, now all I gotta do is figure out what the difference is between loop charged and cross-flow. This engine is 1963 vintage...was loop-charged invented then?
Can you point me to those iscussions about this topic. I'm really new to this site and i dopn't know my way around.

Thanks,

bn

Here's one discussion on iBoats. There are several links contained in the discussion. Google or yahoo or some other search engine: "evenrude loop charged" and you'll probably get 10 gazillion explainations
forums.iboats.com/forum/engine-repair-and-maintenance/johnson-evinrude-outboards/337891-what-is-loop-charged

Ok...Thanks to your help I have the answer. the terms refer to the manner in which the intake air replaces the exhaust in a 2 stroke. From what I can conclude loopers had flat topped pistons while cross flow engines had various shapes of mountains on top of the piston to direct the intake air upwards and force the exhaust air out.

Glad you explained that to me. I really didn't know either....honest

To answer your question - your motor is a crossflow. ALL OMC V4s up to 1985 were crossflows. The ONLY OMCs with loop charging until that point were 3-cylinder inlines and a few experimental racing engines.