Fiddlin thru Brodak website and noticed the aviastar engines. Anyone have any experiences with these. That .61 may be an awesome combo with the light T REX. They are priced very nicely. Thanks John Rakes

Not to nit pick here but supposedly the Brodak imported Aviastars have had some internal changes to make them more suitable for stunt. That being said, for a few $$ more I'd get the Enya 61 CSX from Randy. That is a nice running engine w/excellent workmanship. Now...shouldn't this thread be moved to "Engines"? 

In the fall of 2008 I was down at the Brodak Field and a friend had one of these on those ( a .61) on his Legacy. He asked me to fly the plane and give him my thoughts. The plane needed some trimming TLC and the engine had the familiar schneurle run aways! Since Lou Woolard was there I told him to take it off his plane, give it to Lou, and ask him to set it up for stunt! He did as I suggested and now, one year later my friend is one happy fella as to his Aviastar Engine! Lou does excellent work and made this engine into a fine performer. There's always a way to make it better if you really want to! So John if you really one one of these go ahead and get it! You've got friends who can improve it if it needs it!

Phil Spillman   

If an engine is advertised for stunt/precision aerobatics,  why after spending good money do we have to spend even more to get it run right?  I have one that has been worked on(not an Aviastar) that has been worked on several times and still doesn't run right.  So it has become a sport engine.

You don't, the engines Brodak is selling are not the same engines available from other suppliers. The rework has already been done.. At least thats what I've been told and have no reason to doubt it.

Thanks guys that helps. I did see where there is an engine set up ant tips section to the forum. Since I do not actually own the aviastar yet I thought I was correct where I made this post. Actually you should have mentioned product reviews if it was that big a deal. Thanks again

According to the above mentioned website, the designer is a CL speed champ...

"Our Chief Designer and co-owner, Mr.S.J. Ye started his modeling career in 1952 after his college education majoring in the designing of combustion engines. He was the first to break the Chinese National control line speed record in 1959...He designed and made engines for the Chinese National Team.   Over the years there were 23 various modeling world records being made by his team under his guidance.Mr. Ye is also one of the two FAI approved International F3A judges in China. He has been participating in the judging panels for World F3A events on many occasions."  
 http://www.aviatronics.com/company.htm

Must be a pretty decent motor.

ps..I am moving this to the engine forum!

I have ordered an Aviastar .61 CL from Brodak. I am from Brazil and I will have to wait some days until I receive it.
 
If you, guys, enter in the site of Aviastar/Aviatronics you will see that they tell they put in the Aviastar CL .61 all the experience they acquired when they projected the engine that won the world F2A championship in Ukraine, wined by the Chinese team in 1998.

http://www.aviatronics.com/world.htm
http://www.aviatronics.com/l.htm

If this is true, we wouldn’t have to retime it to stunt operation. I agree that Enya CL 61 CSX is a much better worth value engine, but I am not finding it for sale. Enya says that it is Sold Out and doesn’t give any idea when they will have it again for sale.

It would be good if anybody who has an Aviastar .61 CL for some time, could give us his experience with this engine. I didn’t find very much about it in CL engines forums or a review in an aero model magazine.  I suppose that very few people have already bought or tried it.    

I have ordered an Aviastar .61 CL from Brodak. I am from Brazil and I will have to wait some days until I receive it.
 
If you, guys, enter in the site of Aviastar/Aviatronics you will see that they tell they put in the Aviastar CL .61 all the experience they acquired when they projected the engine that won the world F2A championship in Ukraine, won by the Chinese team in 1998.

http://www.aviatronics.com/world.htm
http://www.aviatronics.com/l.htm

If this is true, we wouldn’t have to retime it to stunt operation. I agree that Enya CL 61 CSX is a much better worth value engine, but I am not finding it for sale. Enya says that it is Sold Out and doesn’t give any idea when they will have it again for sale.

It would be good if anybody who has an Aviastar .61 CL for some time, could give us his experience with this engine. I didn’t find very much about it in CL engines forums or a review in an aero model magazine.  I suppose that very few people have already bought or tried it.   

Pardon, Martin, but Enya 61 CX TN is for RC and I suppose it is not tuned for CL. Is it? I am still looking for some information about Aviastar CL .61 that I have already ordered. Thanks.

Say Bob, any chance of getting a Brodak .61 for a follow up article on this forum and in CL World to compare your prototype Aviastar to the production version? Why the .61?, mainly because that seems to be the engine that most are curious about.  It seems to me that the changes that were made to the .53 would apply to the .61.  Inquiring minds want to know. 

Hi Bob,

Which kind of muffler did you use in the .53? Was it the original or a tongue muffler? What kind of fuel, oil, etc.?
How long did you run it in a bench before flying? Do you think that only two or more shims could give some improvement?  What about the venturi, was it the original?

I didn’t receive my 61 yet, customs here in Brazil spends so much time to liberate packages on Christmas month. As soon as I receive it, I will exam the head and will tell what I find.

I agree that it is a great idea you or Tom to evaluate the .61.

Thanks.     Luiz

Bill - I agree. Unfortunately, when I did the development work on the 53, that was, to my knowledge, the only size available. You're correct in stating that the 61 would be of more interest, weighing less but certainly delivering more useable power.

Liuz - the venturi that came with the engine was too small (.24 ID) and too long.
The final version of the venturi is .348 diameter (this sounds a bit large - I will check it and verify)
I bench ran it for approximately 30 minutes before mounting it on the test plane. I used a simple tongue muffler that I made for a Super Tiger 60. A bit loud but very free-flowing.
The fuel of choice was Brodak 10-23, 50/50 castor/synthetic.
Since it did not come with a needle valve, I fitted a Super Tiger NVA.
Regarding shims, if the engine does not perform to your liking, you can often dial it in by adding or removing shims.

Bob Z.

Luiz,

Unfortunately Enya is no longer making this engine and has no plans for the near future.
Martin

Do you mean that Enya will no longer be making the 61 CX control line stunt version?

 People must be interested in the Aviastar engines , this topic has had over 1100 hits !
 Bill Barber

So has anybody had a chance to play with the .61 yet? I'm really interested in this engine.

There are tons of available affordable engines .46 or less plus the ST .51 but for .60 to .61 there is nothing. Seems like everyone expects you to buy a Pro class engine if you want to fly a .60 size ship.

Mike

     Ok , we are at 1300 hits on this subject and still no one has a Brodak Aviastar .61 report . I guess the only motor they have sold must be the .51 !

   Even if they hadn't, it sometimes takes several seasons to really know what an engine can do and to come up with an ideal setup for it. I know that I wouldn't report on any engine I had unless I was very certain that I knew it's characteristics.

     Brett

I'm interested in these.

According to this, there are 46, 53, and 61 displacements, but all in the same case and the 61 is the lightest.  So as I see it, the only smart buy is the 61.  If you don't need the power, you can choke down the venturi and still be lighter than a 46 or 53.  

I'm curious as to the weight and cost of it's close competators.

I was hoping someone would try one on a T-Rex. With its R/C motor mount it would be a great test plane for the larger SE engines. 

Thanks for that first impression. I wouldn't worry too much about the pince (or lack of it) until you run it. If it starts fine both hot and cold...no problems. I have noticed some ABC engines have a great deal of "pinch" where others  don't exhibit as much but it doesn't seem to effect their run-ability. 

I bench ran the .61 Aviastar.

Before running the engine, I attached the venturi with the spray bar to the cranckcase. One thing that I noticed is that it would be better if it had come with an O-ring for the base of the venturi. The joint wasn’t sealing the air very well and there was an air leak and a play between the venturi and the crankcase, so I provided an O-ring from an old carburetor of an OS-46 SF and fixed the problem.

I used a long Fox glow plug that was more flushed with the combustion chamber than an Enya 3, that is of medium length. In another time I will try an Enya 3. I forgot to bring an optional Enya 3 glow plug when I went out to run the engine.

Because the relative loose fit between sleeve and piston the compression was not as strong as I would like and in the primaries attempts I flooded the engine. Then I removed the muffler and started it without muffler, which is better for the first runs, besides the strong noise.

After starting I looked for some leaking of fuel and bubbles near the back plate, the head joints and glow plug, and I didn’t find anything wrong, so the poor compression is not caused by any leak at those points. Maybe is caused by the loosing piston fit, even.

I got the following numbers after running four tanks of 12 ounces each (the firsts three with 20% castor and no nitro and the last with 10% castor, 10% synthetic and 10% nitro), stopping after each 5 min and open and closing needle valve during the runs:

Master Airscrew 11X7 (wide): 9600 rpm for 4-2 cycle and 10700 rpm in the maximum speed, without muffler.

APC 12X7 (wide): 9300 rpm for 4-2 cycle and 10400 rpm in the maximum speed, without muffler.

APC 12X7 (wide): 9000 rpm and 10000 rpm, with the tongue muffler.

I observe that Master Airscrew is not making 11X7 wide props anymore. This one is an old that I have at home for more than ten years, still new and in good conditions.
These numbers are not great. I used to run an OS .61 SF for RC in a speed of almost 12000 rpm with an APC 12X8 (wide). But, for the other side, we have to consider that the diameter of the air intake of the OS carburetor was 9.5 mm, when fully opened, against 8 mm of the venturi of the Aviastar, and that we use only 16% of oil in fuel for RC. So, I don’t know if these numbers for Aviastar are acceptable or not. My feeling is that they are not good.
I didn’t force the Aviastar too much, yet, because it is new. So, I am thinking in bench running it again, to force it a little more and to try another glow plug and props, but I don’t  know if I will find much better numbers than those, and I am not with much time for this now.
I’d like to hear something about these numbers from somebody who has more experience with CL engines.

Thanks.     Luiz

Not to worry, those are pretty good numbers IMHO. Comparing peak HP with an R/C engine is usually an invalid test as often the quality of the stunt run is more important than peak power or RPM. Also, other than on a 4 cycle engine a 7" pitch prop is seldom used in C/L stunt. I would see how it runs with a 12x6 or 12x5 prop and in flight. The bench runs sound promising though.

Luiz,  your english is great.  Now after running the engine, has the compression come up any?  I too have had engines that seemed a little low on compression until I had put a few runs on them.  Keep us posted.

Bob, Pete and John

I am very grateful for your comments.

Pete, about the props, I was thinking to use a 13X5 (Zinger or Bolly), 13X4 (idem) or even a 12X6 (APC) for CL, in this order. The propellers that I used in the firsts runs (11X7 and 12X7) were what I had, balanced, at home at the moment, and that fitted in the Aviastar, but they can give an idea of what will be possible with the other props. At that time I was interested, too, in make a comparison with the engines I am accustomed to use in RC, as a reference for power. I agree when you say that this doesn’t mean too much, in function of their different proposals and characteristics.

Bob, thank you for your offer. I am thinking in order a head from Brodak and ask them to send directly to you to do the mod, but I think that they don’t have the head or crankcase to sell. I don’t know why, because they have all the other replacement pieces for the engine. I will try to see this with them. An alternative would be to send mine for the job.

John, I hope so; with the ringed engines this is the rule, but with an ABC this is not usual, even though it is not impossible.


Thanks and a Happy New Year for All.

Gents - the offer for the free head mod still stands but please, DO NOT send the entire engine - just the head.
I normally perform the mod immediately and when possible, return the head the next day.
I will also do heads for the 53 and 46.
IMPORTANT: please include with the head a note with the exact bore of the engine so that I can accurately configure the squish band.
Bob Z.

On the middle of January I bench ran the .61 Aviastar again, with a prop 12.5X5 (Master Airscrew Classic). This prop is used in RC for scale models. It is not the prop that I intend to use with the Aviastar for CL, yet, but nearer the size of the one that I plan to use.

The numbers that I got were:

9600 rpm for 4-2 cycles and 11300 rpm in the max speed (without muffler, Fox long plug)

9700 rpm for 4-2 cycles and 11600 rpm in the max speed (without muffler, Enya 3 plug)

9400 rpm for 4-2 cycles and 11000 rpm in the max (with tongue muffler, Enya 3 plug)

As Pete Cunha opined before for the other props, they are not so bad.

In spite of the lack of compression, it restarted easily when hot. The only thing that I had to do in this condition was to bring the fuel, by gravity, until the entry of the Venturi, by disconnecting the fuel line, turning the fuel line down and connecting it again, after fuel arrived. With this, after flipping the prop two or three times, it restarted. When hot it didn’t have enough compression (vacuum) to suck the fuel only by choking the Venturi and hand flipping the propeller, so the necessity to do something more to suck the fuel. This, sometimes, happens with ABC engines in this situation. As it is an engine for stunt, not for speed, this doesn’t bother any much.
.
One other thing that I observed in these last runs is that in one of them the engine ran away when I turned it to up side (70° more or less). Even after turning the engine back to level and opening the needle valve, more three or four turns, its speed didn’t slow down. The only way to stop with the run away was to pinch the fuel line, stop the engine, close back the needle to the original aperture and restart. After then, it restarted normally, in 4-2 T and it didn’t happen again, but it can happen and in flight, that would be worse, so I am considering sending its head to Bob Z to do the mod that he offered.

The compression of my .61 Aviastar, when cold, compared to a typical .61 ABC, giving a number, is about 40% of it. When it arrived was with something between 20 and 30%. It raised a little, after bench running the engine for three sections, but it only hit this value, that I would say is a little below 40%. With 70% I would be satisfied. The growth (10% to 20%) of compression was almost all due to the unburned castor oil between cylinder and piston when the engine stops wet.

So, at first, I intend to order from Brodak another cylinder and piston, with a better tight fit, to solve the problem of compression and, then, I will send the head to Bob Z to do the mod. I expect that with the mod the compression tends to diminish a little, since the volume of the combustion chamber will grow a bit, but nothing to worry about, if the engine has a good compression.

Since January 04, I am exchanging e-mails with Brodak Mnfc, telling about the poor compression of the engine and about my interest in ordering another cylinder and piston assembly for it. My unique condition was that it had a good tight fit. Brodak Mnfc. is always telling me that they would be sending another one, with the fit that I was asking. They only asked me to wait sometime until they have it to ship. They also let me know by enter lines that they would not bill me for this, although I have already said that I would pay for it and for its postage. The last e-mail I received from them was on January 28, telling me that they would be with it in a few days. So, I am waiting for the confirmation of the shipment and the amount to be paid, if necessary.

Luiz

Bill! Sorry for the delay in answering your post.

I received the new cylinder and piston from Brodak by the end of February. They shipped it on Feb/09 and didn’t bill me for this. The long time spent (almost 20 days) until I received it was due Brazilian Post Offices and Customs. The new play has a better compression than the original even though I can’t say it has a high compression (it is more acceptable and reliable than the first one).

Bench running and after braking in it again, I got the follow numbers:

Propeller 12.5X5 (Master Airscrew Classic):
9500 rpm (4-2 cycles) X 11200 rpm (max speed) : without muffler, Fox long plug
9700 rpm (4-2 cycles) X 11500 rpm (max speed) : without muffler, Enya 3 plug
9400 rpm (4-2 cycles) X 11200 rpm (max speed) : with Enya .61 stock muffler, Enya3 plug

Propeller 13X4 (Master Airscrew K-series):
10200 rpm (4-2 cycles) X 11600 rpm (max speed) : without muffler, Fox long plug
  9400 rpm (4-2 cycles) X 11300 rpm (max speed) : with Enya .61 stock muffler, Fox long plug

Propeller 13X4 (Zinger):
9200 rpm (4-2 cycles) X 10700 rpm (max speed) : without muffler, Fox long plug
8900 rpm (4-2 cycles) X 10400 rpm (max speed) : with Enya .61 stock muffler, Fox long plug

These numbers are very similar to those obtained with the original set, and they are not bad as remarked before. It was easy to start (hot or cold) and ran continuously and smoothly as the original.

I showed the engine, already with the new piston and cylinder installed, to a person here who builds RC and C/L engines and told him the results of the bench runs. He suggested me to put the engine in a plane and fly. Although he prefers more compression, he considers that the only way to get a conclusion is flying and that the engine can performs well and lasts for a long time even without a stronger compression.  

 By now I don’t have a plane to install the .61 Aviastar, only a Strega ARC kit from Brodak that I bought together the Aviastar in last November, thinking in installing the engine on it. By many reasons, including the engine, I didn’t mount the plane yet. The C/L planes that I have ready to fly are a Vector 40 ARF, bought from Brodak, and mounted a year ago, and a Pathfinder ARF (Brodak kit) that I bought more recently from Martin Quartin in Brazil, who has a control line store here.  As I don’t fly C/L since a long time, only RCs, I bought the Vector and a .46 OS C/L LA engine to train, but until now I didn’t fly with it. I recently decided to mount the Pathfinder, that is more appropriated to restart with C/L, and installed the OS .46 LA of the Vector on it. The Vector is reserved for the next step and the Strega, maybe, for the further.

So, I can’t test the Aviastar in flight now. It would be very good if any body else, who has a plane to  install it, could fly and test the engine in flight as proposed in a prior post, by Bob Z, in this Forum.


Luiz

Did a search and found this old thread. Ok so 5 years down the line. Does anyone have experience with the Brodak Aviastar 61?


MM