O.S. 46 LA

Ian, what do you do with all of them? Are these all engine that you own? Quite a collection if they are. Ken

Ken Cook wrote:      Ian, what do you do with all of them? Are these all engine that you own? Quite a collection if they are. Ken

Yes - they are mine - all mine! These will be amongst the few I intend to use.

I now have a collection of 46s, 40s - a few 25s, a 15 and a 10.

I have been perusing stunt articles, looking at the engines modellers are using and how much current engines cost.

I may be proficient with smaller glows and expert with diesel but the larger 35 - 60 glows, I have not really done much testing. In my day the majority in the club I was in stunted with Merco engines (cheap) Super Tigre (more expensive).

http://www.ooobopshibam.webspace.virginmedia.com/merco/index.htm

I like the Enyas but they are much more expensive. Then again - nothing compared to Ro-Jett or Double Stars.

Why so many? They are cheap and expendable and there is a glut of them at the moment.

They are not the best but represent excellent value for money and scope for fiddling.

My father and myself could never afford to purchase Super Tigers. I probably should restate that and just say that they were just too much money than what we wanted to spend. They certainly were terrific engines at least the versions I was interested in. However, Super Tiger or World Engines had a real problem in that they would change the versions of these engines on a monthly basis it seemed. They were constantly undergoing changes that unless you knew exactly what you were dealing with you weren't getting parts. The LA engine series I feel is a really good choice. I abuse these engines and they take it. I have some purposely for running hard and I have some for stunt which I just baby. Either way, they really have stood the tests I've given them. Great collection you have. Ken

Sounds like I should start getting an LA here and there for when my FPs wear out. Wayne calls the LA the best mistake OS ever made. I guess that means being originally meant for RC, they convert into a born CL engine.
Rusty

Rusty, the LA .46 is really a great running engine. Many choke down the venturi using the LA .25 .265" which I don't care for. I use the larger venturi's (.273"-.280"). Fuel consumption greatly increases as well as power. Running with the larger venturi requires a 5 oz tank for the pattern. The .265" in the LA depending on the plane usually can be done using 4-4.5 oz's in these parts. I'm sure the higher in elevation, the less fuel your going to use. Essentially it's a very universal engine due to being a .40 size case. It's a drop in fit to mose .40's with more power. I myself have several of the .40's, these are very disliked amongst the control line crowd. I know why, but I just resolved those issues myself using head gaskets and head redesign. I essentially hemi-d the stock head slightly deeper lowering the compression which gave it less of a tendency to run away. Ken

I'll be learning more about the fp40 soon I expect. As soon as the Skyray build is off the table, the Oriental project is on.
Rusty

Ken Cook wrote:      Rusty, the LA .46 is really a great running engine. Many choke down the venturi using the LA .25 .265" which I don't care for. I use the larger venturi's (.273"-.280"). Fuel consumption greatly increases as well as power. Running with the larger venturi requires a 5 oz tank for the pattern. The .265" in the LA depending on the plane usually can be done using 4-4.5 oz's in these parts. I'm sure the higher in elevation, the less fuel your going to use. Essentially it's a very universal engine due to being a .40 size case. It's a drop in fit to mose .40's with more power. I myself have several of the .40's, these are very disliked amongst the control line crowd. I know why, but I just resolved those issues myself using head gaskets and head redesign. I essentially hemi-d the stock head slightly deeper lowering the compression which gave it less of a tendency to run away. Ken

This is what I like about the LAs - they are prime candidates for "fiddling" with and experimentation. While I wouldn't say easy - modifications like Ken has performed are relatively straight forward.

It is easy for me to make new venturi's, modify heads and bench test - setting up for flight conditions is a different story. The all crucial 4-2-4 is something I have never played with or appreciated. My engine work has been restoration back to "as new" or "all out" tuning.

There is a fine art to selecting and configuring an engine set up for a stunt plane, complex and time consuming.

ian1954 wrote:The all crucial 4-2-4 is something I have never played with or appreciated. My engine work has been restoration back to "as new" or "all out" tuning. There is a fine art to selecting and configuring an engine set up for a stunt plane, complex and time consuming.

This applies to control line flying. The older engines like the Fox .35 Stunt and Testors McCoy .35 Red Head can do this 4-2-4 very easily. They are older cross scavenge technology with heavier iron pistons running in a steel sleeve. Not all cross scavenged do this, and so far in my limited use haven't seen it in Schneurles.

Instead, I've obtained what is called a wet-2/dry-2. Engine runs in a "wet" or rich 2 cycle, then cracks to a faster "dry" 2 cycle when doing stunts such as a loop, wing over, etc. Then goes back to the wet-2 when back in level flight. The dfferences between these modes is the speed that the model flies. In a 4-cycle or wet 2-cycle, the aircraft is flying level at a moderate speed. When entering manuevers, it cracks into a 2-cycle causing the model to speed slightly to help better sustain it through the vertical maneuver.

I gather that not all engines are capable of this, and I've seen where that an engine will sometimes run away cracking into a leaner and faster 2-cycle, that never breaks, causing the CL plane to move out a quicker than the flier intended.

So, there is science in the madness.   

I've had pretty good runs with my OS fp35 breaking. I think this may be what you are calling a wet-dry 2, but it accomplishes the same thing. I also don't know which type of porting this engine has. But it sure is consistent, rarely needing a needle adjustment.
Tell me what you think about the break you hear in this flight.
https://www.youtube.com/watch?v=fDlae60LYNQ