stefanP

My Feedback: (2)

What kind of power(hp) does this engine put out? What size props will it swing?.Thanxs for looking,
stefanP

w8ye

My Feedback: (16)

Use a 11-6 prop. The engine has good power closely comparable to most present day 45/46/47 engines. It just weighs a little more.

MyWay

I wouldn't call a 45 size engine that weighs close to 11 oz. heavy.

Flyer95

My Feedback: (1)

A friend of mine really loves these engines 40-45FSR and have a good collection. I sold him two 45FSR to save money for other projects. According to him the power is very good, carburation is perfect, and they are very light and small engines. Parts are usually not available at the hobbystores because these engines are not made anymore. But very often these engines and parts for them show up on ebay.

loughbd

They haven't been made in twenty years. Excellent engines with one draw back. If you knock the muffler off it takes a chunk of the crankcase. I have several and just acquired a ton of parts on E**Y.

Twanger

Tower Hobbies carries the #743 OS muffler. It fits the FSR .40 and .45. Just type "743 muffler" in the Tower search box.--Twanger

loughbd

A muffler does you no good if the flange where it bolts to the crankcase is broken out. I have several mufflers and now 4 more crankcases on the way.

loughbd

It was rated at 1.4HP at 17,500 rpm and the ABC was rated at 1.45@17,500

4dogspete

Just bought an OS 45FSR NIB at an R/C yard sale. It had a glow plug.
Compression was relatively poor - seemed quite poor for a New but old engine! even with the glow plug in.
It starts and runds pretty well with a 10x6 prop, but I would not say it is any where near a 46FX.

Anyone experiencing such low compression with a Niew - Old engine?

Anyone have any ideas as to why the compression is low - it is not a ringed engine.

Pete

landeck

My Feedback: (1)

Pete, if it is not ringed, then it is OS's version of ABC. I have a couple and they run as well as my 46 AX engines. I cann't help you with the compression.

Bruce

1QwkSport2.5r

If compression is poor on a NEW (old stock) engine, then I'd ensure that the cylinder head screws are tight first and ensure the glow plug is tight also. Sounds stupid and mindless, but you never know... I'd also verify the glow plug is of the proper reach. Call me crazy, but after trying a short reach plug (shorter than an OS plug) in a car engine (sorry, throwing in an orange to an apples comparison) I noticed the difference in compression (less with short reach). The car engine in question required long reach plugs.

Tapered bore engines (even the loose OS engines) should have a good pop turning the engine over in operating direction. I say the piston/liner fitment is loose if you can turn the engine over CCW with no prop on it by hand turning the prop driver itself. My TT 46 Pro had virtually zero pinch brand new out of the box (was bought new back in 1992 or so) but after a good break-in I have a really hard time turning the engine over by hand without a prop on it.

Perhaps that OS FSR engine needs to be broke-in the rest of the way. Put a 9x6 prop on it and run it slightly rich at WOT for a tank or two and check it again. IMHO, a 10x6 prop is too much load for a tapered bore engine to get up to proper operating RPM to break-in right. I made this same mistake on my TT 46 and its probably 500-1000rpm short of what it should be turning. It still runs really well, and still has no pinch cold without a glow plug in it.


What RPM was the engine turning that 10x6 prop at? What fuel, glow plug, and brand of prop were you using?

4dogspete

Thanks for your thoughts
Got some more checking to to, but the grandkids are over (+/-) some other sutff, so it'll be a day or 3 before I can check all those things.
'twas interesting tho - when I first started it, it would only run with the -provided- glow plug nwith the glow starter on. would not run when I took the glow starter off. Replaced it with a Tower Hobbies el-cheapo glow plug and it ran fine..
I suppose I'm expeecting around 14k r's with a 10x6 if it is anywhere near equivalent to a newer OS 46FX. Maybe I'm asking too much???
Didn't want to crank it up too hard on the first run, so will try tightening thigns up and put a tac on it.
Back to you mid week.
Thanks for all the suggestions.
Pete

1QwkSport2.5r

The most important thing to remember with tapered bore engines (ABN/ABC/AAC) is run them fast to break them in. A 10x6 is too much load to get the rpm up high enough. If the 10x6 is going to be your flight prop, run it with a 9x6 to break it in at its target rpm rich. Running 1" less diameter will get the rpm up and get the engine to proper temperature and running a rich mixture will keep it well lubricated. I think a typical ABN/ABC .46 engine should be broke in at 16k or thereabouts. Anything less and it will probably end up being down on power a bit.

Good luck and certainly post back what you find.

jeffie8696

These engines were made before noise restrictions and love rpms.

1QwkSport2.5r

I think most engines made in the last 30 years, with the right exhaust system and fuel, will love rpms. The exceptions to this (IMO) are non schnuerle ported engines (baffled pistons) and many lapped iron/steel engines. I am not afraid to wind a .90 up to 15-16k provided good fuel is used and the mixture is rich enough off peak as to get proper lubrication. Some of the bored-out engines (ie: small case big bore engines) may not be as receptive to cranking up the rpm, but an easy way to tell is running a few different props and put the rpm figures into the prop-power calculator thats been posted here and elsewhere to determine the power output.

Just my observations and opinions.

jeffie8696

In my experience some engines just sound "happier" at high rpms than others. A balance of ports, carb opening, etc.
Friend of mine had great luck with a 45 with a 10X6 prop and a pipe on a Tigershark.

landeck

My Feedback: (1)

I have been flying an OS 45 FSR for the last 30 years and I have found that an APC 11x6 or 10x7 work best with it. I do not remember the RPMs I was getting since it was many years ago that I last measured it. The last plane I had it in was a GP Smith Mini biplane and it move out very well with the 10x7 prop.

Bruce

jeffie8696

That sounds reasonable, Iwill hav e to bolt mine on something and give it a try with a 10X7.