O.S. Engines Timeline

[rich gorrill]

Hello all, I like to search E-Bay to try to pick up deals on engines. These questions are for someone who has more knowledge of OS engines then I have, #1 when did  OS stop making the .40 size engines? #2 when did the blue case engines come in? #3 When did the silver .25 and .46 replace the blue case.  #4 Power wise, is there that big a difference between the .40 and the .46.  I would like to make a Brodak Pathfinder my next project and was wondering if either size would work on this plane. Brodak says their .40 will work, is the LA .40 comparable. Most of the engines I have purchased on Da Bay are RC, I just convert them for control line.

T.I.A, Rich

[Wayne J. Buran]

There is a big differance between the LA 40 and LA 46. The 46 is a much better performer out of the box. Same size case. I would choose the 46 over the 40 any day. Makes no matter to me blue case versus silver. The 46 is a great choice for the airplane you are thinking about.
Thanks
Wayne

[Tim Wescott]

Based on the very little experience I've had with it, and the very great number of things that have been said about it here, the LA 46 is a hugely versatile engine as far as what size of plane it will power.

I'm getting set to build the Next Great Thing and asked here what size planes would work with the LA 46, and got answers that ranged up to almost 700 squares, although the majority seemed to feel that I didn't want to go much above 600 squares.  On the small side, I'm flying a Fancherized Twister (490 square inches) with an LA 46, and I couldn't be happier with it.

[Mike Scholtes]

Having built and flown a Brodak Pathfinder (excellent model) and having a lot of experience with the LA46-S, I think you should order a new LA46 CL version from Tower Hobbies and put it in the Pathfinder. By the time you purchase a CL venturi and NVA you will have about the same investment as converting a used RC engine with an unknown history. Check out the "LA 46" info in the Engine Setup section.

[Randy Cuberly]

Hi Rich,
What everyone has said here is absolutely correct, however I'll try to answer you question a little more thouroughly.

The early LA40's had three intake ports in the sleeve and likely produced more all out power than the later ones but were nearly untamable for stunt.  In the later 40's OS did away with the boost port and ported it pretty much like the 46.  These later 40 can make a reasonable stunt engine and are easier to deal with than the earlier ones.  I don't know when the specific dates of anything occurred.  The CL versions ("S") came out a couple of years after the RC versions.  But of Course, OS had to have their lawyers demand that silly remote needle valve assembly which just adds complexity and reduces reliability for CL.
The 46 with a conventional Needle valve assembly either OS, ST, Or Randy Smith, is hands down the best out of the Box CL stunt engine on the market for under $150.00.

The blue paint on the early engine gave production problems at OS that they eventually got tired of dealing with so they eliminated it.  Other than the color it changed nothing.
The 40 went away, I think, simply because the 46 out sold it about 6 to 1, even for the R/C guys.  The 46 is more powerful, easier to use, an a little bit lighter due to a thinner sleeve.

I do agree with the comment about simply buying a new 46 unless you can find a used 46 that comes from a known quantity that has been modified (needle valve assembly only) by someone in the stunt community that you can trust, like Randy Smith, or the ones from RSM that are done by Larry Foster.

Everything said above pretty much applies to the LA25 also.  They will fly anything that the old Fox 35 was used for and are actually a little more powerful.

Randy Cuberly

[GregArdill]

This link, shows all OS engines.
This one is their earliest engines, but click the period you want.

http://www.osengines.com/history/ostimeline01.html

Greg

[Paul Taylor]

I will trow my 2 cents in just cause as most of you know I love dem blue engines.

I can say with out a doubt you will not go wrong with the 46. Blue or Silver. As stated buyer beware off ebay, but I have had good luck. Unless the head is just burnt - means ran had and put away wet. The way most RC guys run an engine WAO cause they dont know how to set a needle.

We have one that came right out of the box bolted on the plane, ran about three tanks thru it and went flying. Still has the plastic backplate and stock remote needle. Set it at. 9600 rpm and flys great on about 4oz of 5/22.

Now i have some that have metel backplates and OS NVA that were converted RC engines. Runs good.
If your thinking about getting one and making a stunt grunt engine- you can buy them from Randy Smith for about the parts you would purchase. ie backplate and NVA.  I have one and it will pull my porker planes around all day long with way more power then I need for a 53oz plane.

Did I ever tell anyone I love dem blue engines?

[Will Davis]

 1 vote  for the la 46, don't forget  if you have  some old worn out fp 35 or 40, the Venturi and backplate will fit the la 40 or 46. The  46 is lighter,  more usable power , and fits the same mounting holes as the fp 35 and 40

[FLOYD CARTER]

There was a time when I absolutely had to find an OS 46 VF.. mainly because I wanted rear exhaust.  Then, the absurd prices changed my mind.  So I have been using a couple of OS46LA engines with great success.  I just wish I didn't have to deal with a side exhaust and oil all over.

(Yes, I also fly electrics--anticipating your comments about oil).

Floyd

[Mike Scholtes]

This is drifting a little off topic, but the grey rubber exhaust deflectors, even when trimmed pretty short, do a good job of directing most of the oily exhaust away from the model. Not really a problem on the several models I am using the LA46 on, though this observation would apply to just about anything with a conventional tube muffler. (Vector, Smoothie, Olympic)

[rich gorrill]

Thanks for the timeline Greg, it answers all my questions about when the blue case LA was introduced to replace the FP, seems around 1996-1998, and when silver replace the blue case, between 2000 and 20004. I have purchased 3 OS motors from e-bay at very good prices and so far all were in perfect condition and ran great. Seems like most sellers on the bay are very honest in their descriptions of what they sell. I only had one problem and that was a guy who sold me a Fox engine with a stripped needle valve nut but one e-mail and he sent me a whole new NV assembly.

Rich