NeveSSL

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Hi all,

Just picked up an Avistar AWARF with everything but fuel for $125. Only problem is that its been sitting for 8 years! I'm going to have someone at the field go over it with me to make sure all is well, but it was stored inside a guy's house and not in a barn or anything, so I believe it will be fine. And the engine and radio are working great already.

Anyway, my boss gave me a Harrier .46 with a .52 Surpass and loaded with servos (thanks, Zach!). Needless to say, I don't feel comfortable learning on that beast. So I'm replacing the 1987 .45 Fox Quickie that's in the Avistar now with the Surpass. The local club is at a public park and I think noise can be an issue, so to make sure I'm ok, I'm putting the 4-stroke in.

Any thoughts on this? I think I need to mount it sideways due to the carb and fuel tank, but I'm not 100% sure. And if I do that, how do I do the nosegear? I think its built into the engine mount, right?

Any help is much appreciated!

Thanks,

Brandon

noveldoc

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I've flown that engine in a Kadet Sr and Seniorita, a 4 Star 40 and a Tiger II. IMHO it is a great training engine.

Tom

NeveSSL

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Thanks, Tom! Good to hear.

Any thoughts on mounting it?

Brandon

cfircav8r

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The carb is at about the same level as a two stroke. Dont let the fact that it's an updraft fool you into thinking the fuel tank will be too low. It's the carbs position not the intake that matters. You will have to have it more forward than the 2 stroke but otherwise it should be just fine upright. That said if you still turn it sideways you can purchase a nosewheel bracket seperately if there is room (about 1 1/2") or you could convert it to a convetional gear (tailwheel.) Hope this helps

NeveSSL

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Awesome... that does help! Thanks!

I need to go outside and take each engine off. I just remembered, though, that I need to find the right size hex for that stinkin' Fox engine's muffler... its an odd size and I can't get to the mounting screws without first taking the muffler off... :-/

Brandon

cfircav8r

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I have found some were odd half sizes, and got lucky I had a few Misc. ones lying around that fit.

mike109

G'day

I think your 52 Surpass will be brilliant in the trainer. Once upon a time, many years ago I put an OS 48 Surpass into a Thunder Tiger trainer. Everyone looked at me as if I were mad but when they saw it flying, several people asked if they could have a fly and so I let them. They were amazed at how well a four stroke worked in a trainer.

These days I have a number of trainer type planes and they all have four strokes in them. The fact that four strokes are happy to plod along at about half power and then leap into action if more is needed really helps in a trainer. My latest Four Stroke Trainer is a World Models Skyraider Mach 1 with a Saito 62 in it. It is brilliant. Plenty of power if you need it, but also happy to poke along at part throttle.

You won't have problems if you mount it vertically. Mine are all mounted like this and some have their carby quite a bit higher than the tank centre line. One of my Kadet Seniors has a Laser 70 and its carby it right at the top of its head. This makes it almost two inches above the tank centre line and despite this it runs perfectly and even flies inverted (badly).

Enjoy.

ChuckW

The .52 will be excellent on that airplane. I've flown a trainer with this engine and it was great. Don't worry about trying to mount it sideways; it will be just fine sitting upright.

NeveSSL

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Thanks for all of the posts, guys! Upright it is. Can't wait to get this baby in the air!

Gotta get a good selection of hex wrenches, too...

Brandon

Campgems

On a quick trip through this thread, one think is missing I think. Prop size. First, you just can't go wrong with the .52 surpass. Great engine. They will swing a 12x 6 prop with little effort. You may have trouble landing though, depending on the plane. I found that the APC 12.25 x 3.75 was a great match for my trainer and the 52. You never flew at full throttle, but the pull of that prop/engine would about suck the covering off the plane if you needed the thrust. More importantly, that prop cut back to 2200RPM was like putting on the brakes. It cuts your top end down by about 30%, but you will not fly the trainer at full throttle anyway.

I've been off flying for a while, some eye issues then something else, Ibroke out my old Sig Senorita this week to get the hands working again. It has a Supper Tiger 40 on it and it is really to much power, but it's there if you need it. It will take off at less than half throttle and once it gets to altitude, it needs less throttle. Landing though is an issue. The 11x6 just had to much speed at idle for the plane to settle down. I dug out a couple of the 12.25 x 3.75 APCs tonight that had kissed the runway a time or two to many and shortened them to 11". I'll see tomorrow if this was a good choice. It will give me the ground clearance Ineed, but still have the low pitch. Engine tuning will need to be revisited again though.

That engine will run just fine, upright, on it's side or even on a near inverted as mine was on the fun-star I last had it on. They are just a great engine. Only one improvement needed.Get a velocity stack for the 56A engine and put it or your carb. It will keep things much cleaner. http://www3.towerhobbies.com/cgi-bin...?&I=LXRPX4&P=ZI see they have jacked the price up by a couple bucks since I bought mine. A piece of copper tubing fit to the carb will do the same. This one fits and still isn't all that expensive.


Don

NeveSSL

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Many thanks for the reply, Don!

I've actually been wondering about props. I think it currently has a 12x6 K Series on there. I may very well go down a bit in prop size. I hadn't even thought about th effect the prop pitch has on landing while at idle... thanks for bringing that up! It makes perfect sense.

Brandon

jeffie8696

Just maidened my Tower Trainer 40 with a Magnum 52 four stroke today. The 12" Super prop Iinstalled did give landing issues mostly because Iam still learing how to float them in. Otherwise it flew great and the Magnum 52 is starting to break in and become a reliable engine after about a gallon of fuel now.

mike109

G'day

I like 5 pitch props on trainers. I used to use 11 x 5 and Bolly 11.5 x 5 props on my smaller four strokes. As Campgems said, lower pitch makes landing easier and helps you to slow the plane down. This is especially important on floaty trainers. My dear old OS FS 40 loves a Bolly 10.5 x 5 prop. Anything else and it just does not pull well enough to fly.

The much maligned K series props are good for trainers too. They are not quite so efficient but they are tougher and will handle a minor prop strike much better than an APC. And being less efficient, they don't make the problem of slowing down worse. Cheaper too.

Stuntpilot51

Brandon,
I flew my Avistar many years ago with my first O.S.61 surpass. The perfect combination, you won't be disappointed.

I think I was running a 12-7 or 11-8 and it was quite fast.

The 52 has probably the same power as the early 61.

Picture is kind of crappy as it's a picture of a picture, we did'nt have digital cameras back in the early 90's

Augie11

Keep in mind that the Avistar is actually one step up from a basic trainer in that it has a fully symmetrical airfoil. This gives it greater aerobatic capability than your standard trainer but also makes it less of a 'floater'. So if this is your first plane, make sure to have a qualified instructor with you until you're comfortable with her.

RCVFR

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It's a semi symmetrical airfoil.

NeveSSL

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Yes, I am aware of what the Avistar is. Part of the reason I wanted it! I've flown before, about 6 years ago, but never got to solo... I got really close (I was landing by myself), I just didn't have time to make it to the field often enough. Now that I'm out of college and working, I'm hoping to finally get into this the way I've wanted to literally since my 12th birthday! I'm still going to buddy box, though, for sure. I don't think it will take me too long to get into the swing of it again, but I'm not taking any chances I don't have to, either.

Brandon

NeveSSL

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Oh, and I forgot to mention... my first plane was a .30 sized Wild Thing with an OS Goldhead .60 on it! It would take off in about 4 feet... So I do feel more than comfortable with the Avistar... however, not so much with the Harrier 3D!

Brandon

Augie11

Great! I'm glad you're aware of the planes flying charcteristics. You'll love her once you're flying her on your own. Best of luck! Oh, sorry if I said fully rather than semi-symmetrical. Either way, she's no basic trainer.

NeveSSL

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I've heard a lot of great things about this plane and I'm anxious to get her in the air!

Brandon

hsukaria

If you plan on flying from a grass field, I recommend converting it to taildragger. A club member had trouble with it as a trike, but after he converted it to taildragger, it was really nice off the grass.

By the way, I am surprised that the 52 came off a Harrier 46. That plane is quite heavy and my OS 70 Surpass is just enough for it to do 3D, but I can't pull it off a hover, not enough power. So the 52 would be just enough to fly the Harrier as a pokey sport plane, not 3D.

NeveSSL

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We fortunately have a paved runway at both fields I go to. I may still convert it to a taildragger at some point. I'll just play it by ear.

Yeah, the Harrier was given to me and you're right, it is a heavy plane. I think the .52 really just pulled it around and not a whole lot more. I've seen the Harrier fly a few times and it made it along alright, but it was nowhere near 3D.

Brandon

jeffie8696

Iam going back to an 11X7.5 prop to see how it reacts. Iused this prop on my PT-40 with a Saito .50 and it was a good combo. Ifly off petromat, love the stuff.

GarySS

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For an OS.52 I recommend a Master Airscrew Scimitar 12x6 for good performance and sound.

ericzombie

You asked a bit about prop size. If you haven't yet had a chance to find the manual for your engine, I highly recommend googling for it (or see if O.S. has it on their website) to give you exactly a good idea of what props it should be turning at what RPM.

Also, nice favia in your avatar