I'm planning on changing engines in my OMP FF540. Do you guys know which .46 - .51 size engines will interchange with the O.S. .46 without carving up the mounting rails too much? I swapped the O.S. with the TT 46 and MDS 48. The holes were fairly close and they fit between the rails. I was wondering if others like the Magnum 46, GMS 47, Tower 46, Webra 50, Evolution 46 etc. will fit fairly close? How many others are there that you have experience with that will fit closely to the O.S. .46? The next question would be; How many of them that will interchange can use the same muffler / header? I thought this would be good information to have while in the market for replacement engines. The motor length and height are not critical, mainly just the width and bolt patterns

Thanks much,

John Wells

The OS 50sx is a drop in replacement for the OS .46 fx... as far as the mounting holes go. It requires about another 1/4 inch behind the engine for the needle valve assembly. The needle valve is in a slightly different place as well, and is adjustable to the top or side of the engine and is in a slightly different place than the .46. The muffler mounts are identical.

Webra .50 fits in the same hole as a OS .46 and .50.... A Super Tigre .51 and MVVS .49 will fit too....

I know... cause I had all these engines on the Burrito... No mods.

Hey Paul, in your opinion, what would be the best of those motors? I'm looking for a 50 2s for my omp. Used to have the saito on there, but that's on the hype now, so I have to get a new engine.

The tower is the same as the os and muffler mounting is identical. If you go to the Macs headers website, the have a chart that shows which part number fits which engine. This is how I found out the tower and FX were the same. I know you asked paul this question, but I'll put in ny .02. Get the Webra .50, it was recomended to me by Paul and some others. It has tremendous power, feather weight and is reliable as all getup. Since it has been broken in, I have hardly had to use my starter.

William

How about for price on the webra? Best spot to get one? Best spot that I've seen is on chief aircraft's site for $129. http://www.chiefaircraft.com/cgi-bin...els/Model.html

yeah, same at horizon. I got my LHS to match the price and it saved me shipping, but had to pay tax. Worth every penny.

For my money.... I'd go with the Webra .50!!

Hi,
An Irvine 46 will drop straight in as well. I would expect a 53 would be the same, but I cant confirm that. The irvine has the same mounting bolt pattern and spacing for the muffler too.

Stefan

The Irvine 53 will go in the same holes also. That is what I did to mine I switched from a 46 to
a 53.

Is the Webra 50 Ringed?
ringed engines should (in theory) be better with large props and throttle response than a ABC or ABN
Any thoughts on that?
I like how ringed engines last forever also

The GMS 47 and the Magnum 52 XLS swap out with no problem (same demensions).

Jon

Webra 50 GT from Quantum is $129 and no shipping. I love mine (Horizon fixed a sticking throttle). It turns a 12.25x3.75 with no hesitation in spool up and I don't even have it perfectly tuned yet.

I've gotten a bit of "too loud" commentary at the field. The muffler is straight through. I think the sound is great, but am thinking of putting on a MCP.

Just haven't figured out which Mac header to get. I think it's the same as the Super Tiger and Webra 40. Anybody know? Part number?

I think Webra makes or has made three versions of the 50; ringed, ABC and ABN. What I believe is Webra's website shows a ring in the 50GT.

http://www.webra-austria.at/index.htm

I have an Aero 50GT in a Quickie 500 plane and it has been a great engine.

Eric

I love my MVVS 49, hand start on first try, plenty of power and you can get a nice mini-pipe from MVVS for it also. 12 1/4 x 3 3/4 is perfect. Works well with MCP.