em14

Are the Avistar engines still in production and if so, who is the US distributor?
Leo

049flyer

My Feedback: (18)

It was Sig although I'm not sure they still are. Nice engine with a terrible carb. Too bad! I think Brodak is stocking them with a control line venturi, they might have the RC version. You would be better off buying the CL version and fitting a Perry or OS CARB.

jeffie8696

SIGis still selling them, and if you get one with a bad carb they take care of you. Ihave a lot of experience with them over the years.

airraptor

My Feedback: (66)

Yes sig is selling them. they have about 100 or so of the 53 and around 1000 or so of the 46 engines. If you do get the 53 you need to make sure the lower rod bushing has a radius on it where it goes on the crank pin. it it doesnt then it will spin the bushing and break on you. stock they are not super strong. the 53 has just a bit more power than a OS 46 AX engine on the 10x7 APC. i would like to buy some more though as they are a good price. I had my engine guy make one in to a what we call a stage 3 lol and it turns a 10x7 APC at 17,000 with a red muffler.

also one other thing on the 53 is that the head button is kinda soft so make sure you check the glow plug everydays flying to make sure its tight. Do not over torque them. i some people put them on with T wrench's ( all engines) and het the way to tight. i think 20-30 inch pounds is plenty.

em14

Guys thanks very much for your guidance and help. I think this is a sleeper and will fill my needs well. This morning I ordered a Avaistar .46 and am very much looking forward to its arrival. airraptor - does the .46 have the same things to clean up as the .53?
Leo

airraptor

My Feedback: (66)

i havent messed with the 46 yet. i need to get off my but and order a couple. it wouldnt hurt to check the rod though.

plaurence

My Feedback: (2)

Would you explain what you mean by lookng for the radius on the bushing?

Peter

jeffie8696

On the lower part of the con rod where the brass bushing is there should be a slight camfer to the opening on one side, the side that faces the crankshaft.
The 46 has a different head than the 53.
If you get a good one you are golden, if you get a bad one SIG will still stand behind it so you are golden anyway. Ihave about 7 of em.

plaurence

My Feedback: (2)

thanks understand. Are you saying that the bushings are on occasion being placed on the wrong way?

blw

My Feedback: (3)

Some connecting rods have a beveled edge on the bottom for fitting on the crank pin. The chamfer faces the crankshaft surface that touches the con rod.

jeffie8696

Ihave heard of a few connecting rod failures and this is the first time Ihave hear a viable explanation, problems are still rare and since SIG will stand behind them they are a good deal.

Turk1

I dont think wrong way mount of the rod would make a problem.Only some slight contact with backplate maybe.I guess the crankpin root will create the needed chamfer in short time.Only possible risk is the displaced oil hole of the bearing may cause the lubrication problem.

Robert Gelina

Hi All! The .53 size engines ar all gone. They have about 200 of the .46 left. I have 30 of them if anyone wants one.
Bob

airraptor

My Feedback: (66)

Wrong wrong do you even own one of these engines? The rod has a pressed in bushing. the bushing didnt have any chamfer at all. the crank pin has a small radius. aluminum heats up the bushing isnt held in as tight and and then spins. when this happens no oil gets to the center of the bushing via the oil hole. it over heats and breaks the rod lower end or the bushing splits. after it destroyed that engine I tried another ran it stock for one tank and found the bearing spinning. that is when the issues was discovered. So if any one has a new 53 engine dont run it. pull the rod and check for a small chamfer on the lower bushing. if it doesnt its easy to make one ans it doesnt have to be super exact. make it and then take a very tiny center punch and "peen" the bushing in four spots on both sides to hold it in.
the chamber isnt very good on this engine even though it looks normal. it needs to be opened up a little but if you dont know how DO NOT do this own your OWN.

Turk1

Hi Raptor.I dont have any Avistar brand but many similiar Chinese made engines.And I have met many rod cases.You wrong.-Unless bushing tolerances are not proper machining- a pressed bushing never moves so easy. Plus bronze bushing will get heat due to friction to have a chamfer, not alu. rod.Only disadvantage of wrong way mount of rod is - I mentioned above-, changed oil hole position. If user has good castor ratio in fuel, that position also would make no problem.If your bushing is spinning into rod (I have similiar problem with only one engine) you can be sure that rod has wrong machining,not operational fault.My engine was working without a problem though until I discovered by chance and fix it.

airraptor

My Feedback: (66)

Turk 1 until you have one of these engines and see for your self any you say is invalid. say what you want but your are wrong. Dude the engine make heat. everything in the engine heats up. the rod cold may fit the bushing well but once it heated up the tolerences changed and the fact there wasnt a chamfer on the bushing allowed it to spin. go some where else with your thoughts. You dont even have one of these engines. SO YOU HAVE NO EXPERIENCE WITH THIS ENGINE.

Turk1

Sorry but you seem wrong Raptor.Do you think lower rod end is hot?Wrong.This is an alcohol engine and the evaporating alcohol directly hits lower end of rod so rod is cooler than bushing.
Also An Avistar engine is not differ from any of glow engine rod,all same.And I still insist bushing (if trying to have chamfer by friction of wrong way mount) has more heat than rod.Yes I dont have any experience of that brand engine but too much on very similiar manufactured other brands.You may only say,"Avistars has many faulty manufactured rods so bushing may spin" then I stop insist.

airraptor

My Feedback: (66)

Turk
three engines spun the bearing.
fixed by ading a small chamfer before running the engine. no bearing spun after the chamfer.

so be quite your not making any sense.

Hobbsy

My Feedback: (102)

Here is a shot of the chamfer side of a connecting rod, now, it depends on whether the crankpin is machined onto or pressed into the counterwieght as to whether or not it needes the chamfer. The pesssed in one will not have a fllet, therefore no need for a chamfer. Also gents, we need to tame the near name calling attitude building here, Thanks, Dave

em14

airraptor - I think I must ask this question again before I start my .46! So do you know if anyone has a problem with the .46?
Thanks
Leo

jeffie8696

I have seen it happen to the 46 also.

airraptor

My Feedback: (66)

EM I am not sure on them. If you know how before you run it pull it apart and see for your self. I do know that sig stands behind them and will repair it for you if something did go wrong. I always pull every engine apart no matter who it came from as even the best can make a mistake. i do know that I should have bought more of the 53 engines for that price.

yes pull it apart and look at the rod. Hobbys gave a good description of what a normal one looks like. On the 53s I had it looked like the bushing was pressed in and then the rod was machined. no chamfer at all and the bushing was flush with the rod.

jeffie8696

I have had at least 8 of the 46/53 Aviastars pass through my hands and have seen one rod fail.

blw

My Feedback: (3)

I haven't seen one of these engines, but I would be surprised if the crankpin wasn't a press fit. You might want to fly them at least 1000 rpm below max.

jeffie8696

It was suggested to me by one of the owners that the engine is optimized for slightly lower rpm and a larger prop than typical of similar size engines.