OS46LA v ST G51 ???

I'm keen on getting one of these motors, the thing
is either one needs more money spent on it out of the
box! the LA needs the backplate & NVA assy. changed,
and possible venturi selections as well.

The STG51, mmm....apart from trying different venturi's
and using a tounge muffler (needed for LA as well).not much else,
OR is there, more recomended setups/mods neeeded for the
STG51??

Price wise the Tigre is slightly more expensive but
it may seem a better motor for long term stunt use.

Would appreciate everyones recomendations on these two
motors, especially the "out of the box" changes needed
on the ST G51.

A merry Xmas & Happy New Year to all!!

rny.

Hi Ron,
I dearly love my ST 51's. I have to believe they have more power than the LA 46. I think it comes down to what size plane your are planning to use it in. I have three: 1 ten years old from Tom Lay which is a horse! It flew my 64 oz SV-11 with authority. It now is the #1 engine for my USA-1 over 700sq. in about 54 oz. This set up doesn't care what the conditions are, it just pulls through.
#2 is a Tom Dixon engine, and it is just slightly *tamer* than the T&L one, but I could open up the venturi and get the about the same power. #3 is a NIB of the Chinese assembled variety which I just recently got from Bill H. According to the engine gurus, it has a different sleeve from the R/C version, and is timed for stunt.
I have always run a 12" X 4 3/4 to 5 pitch. prop on mine. Right now, #1 has an Eather 3 bld. 12' X 4 3/4 pitch.
I don't think the 46LA would be happy at all with this prop.
On the new version, the NVA is through the venturi, which I plan on changing to a ST "sprinkler" type venturi where the NVA holds the venturi from the top reear like the 46 set up.
So I vote for the ST 51~
Happy Holidays!
Bill <><

Bill, the LA would like those props just fine. I run three of them with no changes from the box. Remote needle, plastic backplate and stock venturi (they vary slightly there, though). Having said that, a really good ST .51 is a little stronger. I don't know the weight difference, but I'm guessing the newer bb ones are slightly heavier than the LA and the really new ones even slightly more heavier due to the extra fin metal. Interested if anyone can give a weight comparison. Both engines are great. The .46 LA is deceivingly strong.

I know from exp you better tighten the heck outta the back plate screws on the os46la as i lost mine on my 40 during the first flight and i even tightened them up somewhat but was afraid that if i tightened them up to tight it would do like a tranny pan does on a transmision and warp in between the bolts and leak but you can also put a lil dab of rtv on it to stop that just dont over do it on the rtv. I replaced the phillips head screws with allen head screws on my osla40 and havent had any problems yet to speak of. As far as the needle assembly i would run the replacement one as i have heard that they all start to leak after some use i havent changed mine yet but i do plan on doing so later down the line i might use the stock just to see how long it does take to start leaking but have a replacement for it on hand till i do need it

steve

The superglue kid

Hey thanks Bill!!

Heaps of good info. here.

Though I forgot the "new" Tigres
are from China now,so are the reports on these
in regards to the timing is set up for stunt use,
is that right?
So the "newer" Tigres in theory might need less
work on them out of the box.

Yes, the "new Chinese ST 51" is supposed to be timed better for stunt.
I agree with Patrick R., that's what I was inferring when I asked what plane you were planning to use them in.
As to the Stilleto 660, as long as it's fairly light, the LA 46 should be plenty for it. I think the LA 46 is more akin to the St 46 but at a little higher rpm operating range.
Bill <><

LAST EDITED ON Dec-26-03 AT 12:13 PM (CDT)
 
Comparing the OS LA .46 & The Super Tigre G .51 is like comparing apples to pears. The LA .46 has the power of a vary strong .40 & the weight of a .40. The ST G .51 has close to the power of a .60 with the weight close to a .60. You might put an LA .46 on an Oriental or Nobler but never a ST G .51. These are 2 different class engines (Used on different size planes).
The LA .46 weighs 256 grams. The ST G .51 weighs 320 grams. No mufflers.
This is just my opinion. I own 4 OS LA .46s & 3 Super Tigre G .51s.

Patrick,great info. on both motors.

Would the OS46LA work well in say
a "Stilletto 660"?

LAST EDITED ON Dec-27-03 AT 03:02 PM (CDT)
 
I'm not real familiar with the Stilletto 660, but I would not be afraid to put the G.51 in it, and probably would. I just ordered a new G.51 CL from Tower ($99.99), after figuring the new piston, cylinder, rod and wristpin for my old one would be $64. The ring was another $8 or more, but I already have some Bowman rings for it. I figured it would make more sense to get the whole engine, and I'll get to compare the two, try the blocked boost port, etc. "Gotta have spares" (a famous quote from R.F. Stevenson of Seattle Skyraider fame). Steve

http://www.nwskyraiders.com/index.html

I do not have the plans for the Stilletto 660. Need more imfo.
I would say the OS LA .46 powered plane should be about 580 to 620 square inch wings. The Oriental Plus by Dee Rice in the latest Stunt News would make a great OS LA .46 powered stunter if you did not want to run a piped engine. 605 Square inches. Classic lines.

I would definately go with the ST 51 on the stilleto. Both of these motors are great values for the price, but as was mentioned above, they are really for different applications. I use a LA 46 on my pathfinder and a ST 51 on my Magnum, which I believe is about appropriate for each engines application. I fly at 5000+ ft altitude, so engine performance is critical. My pathfinder is 48 oz (620 sq in), and even though the LA hauls it nicely, there are times when I wish it had a little more zip. Until I switched to a 3 blade bolly on it I had considerable wind up and some run away problems.
The ST 51 is on my 56 oz (700 sq in) Magnum. Even on 5% nitro fuel, at 6000 ft altitude, it will fly the entire pattern very well in 4 cycle. This is something that the LA would not do well with my Pathfinder. In fact I run my ST 51 so that it breaks very little, a constant 4 cycle at about 5.4 sec laps with 64 ft e-e lines. This engine is a horse, and I can only imagine what it would do at sea level with 10-15% nitro!
Yes it is a bit heavier than the LA, but it is a ball bearing engine after all. If you are looking for an engine with .60 type power, in the 10 oz range you really cant beat it at less than a hundred bucks.
Use the LA 46 for models like the pathfinder, cardinal, Vector 40 etc.
But the ST 51 would be an ideal choice for your stilletto IMHO.
Brian

Guys

Have a look at www.supertigre.com, it's worth a look and is current, mentioning Great Planes and Hobbico.

The parts lists for the CL and RC versions show different part numbers for the cylinder sleeve but there is not much more info about the CL engine except they list 10.98 oz for the CL version.

LAST EDITED ON Dec-27-03 AT 03:53 PM (CDT)
 
I have both engines and I slightly dispute the notion that both need more done---except replacing the stock muffler on the ST51 and to a lesser extent, the stock LA muffer.

I have run 3 LA's with the plastic backplate (2 25's and a 46), and have never had a problem with the plastic backplate coming loose (although I won't dispute that it hasn't happened-I just don't think it is a common problem). I haven't used the remote needle for long , primarily because they have usually been broken off due to inverted landings (LA25's), and the 46 was bought (ab)used from a RC application and had been pre-broken for me.

Someone I know and respect was really impressed with my LA46 after bench running it, saying it was only a little down in rpm from his ST51 with the same prop, which he was running on a Magnum-sized stunter of his own design.

My 2 cents.

I tend to agree with Alan on this. I also own both engines and think they ran fine out of the box. The stock mufflers are too heavy and I switched to a front needle valve on the LA .46.

I have the plans for McDonald's 660. Nice plane and he used a Tigre .46 on it. If you build light, the .46 should work. If not, go with the .51.

I personally feel the .46 would be too much for a stock Oriental. Mine weighs 45 ounces and flies fine with a Double Star .40. Unless you really want the excessive horsepower, look for a bigger airframe. One of the local guys has a profile Cardinal with the LA .46. It's slightly bigger than the Oriental and don't forget that the profile fuselage will have more drag. The LA .46 works great for him.

Two more cents.

Ron King

I favor the ST 51, but that's probably largely due to my luck with OS engines; that is to say, none. But I'm aware that that is due entirely to me. I've seen other's fly OS engines well and have zero problem with them. I have a particular talent for picking bad ones.

:) Hey great responses!! to my original query
on the OS46LA v STG51.

From most of the information written on these,
personally I too would favor the STG51 for the
"Stilletto 660" over the LA, though if built "light"
the LA could still be a reasonable choice.

Some of the guy's mentioned problems with the O.S.
quality wise, but these are minor and I recall
back some years ago that the STG51 "also" wasn't
a swiss watch dealing clearances & chroming.
(guess the old Italian fact. was trying to keep
up with the Asian imports at the time).

Regardless,the "Tigre" seems "the" pick,
especially with the new (chinese) ones,reported
to have the proper stunt timing.

Many thanks guys!!!!!!
rny.