jeffie8696

Got this engine today from SIG and couldn't believe the price!![X(] I broke it in with Sig 5% nitro with 20% castor. Mine liked a hot plug with this fuel so I used an OS A3 and I broke it in easy since it was so tight. On my first full throttle run (after an fairly easy breakin) it spun a Master Airscrew 11X6 to 13,000 using a mild tune since it is still breaking in. My calculator says that is worth 73 mph and 7.07 lbs of thrust [X(]. Currently it is the most powerful .46 in my collection. And I haven't even started tweaking yet.


Funny , I was thinking with a name like Aviatronics they would make electric motors or servos or something. Nope just really powerful glow engines.

To find this engine in the user reviews it is listed under Aviatronics.

jeffie8696

Playing with the Avistar again today. Before I got run indoors from the rain I thought to raise the compression a little and see what happens. My Sig 5% is a very conservative fuel but I just love it for breaking in new engines and just messing around in general since I know my engine is getting a lot of protection. Anyway I used the same setup as before with the A3 plug but I removed the head shims one at a time (they provide 2 ) and with both removed I got a real steady 13,350 . Ran the numbers across the thrust calculator and came up with 75.8 mph and 7.45 lbs of thrust. And I am still in the breakin process so my tuning is still conservative.

You should check out the cool KLINGON looking symbol on the engine, yes I am a Trekkie to some degree , sorry.[sm=49_49.gif]

ProBroJoe

Sounds like a pretty decent runner! Wonder what it'll do with a 10 x 6, 11 x 5 or 12 3.75?

jeffie8696

All in due time. I don't have any 12" props to try but I have heard it will work. Next step for meis shimming and higer nitro. I just tried some 10% nitro 20% castor from Sig and I changed the plug to a colder OS #8 and it gave me 13,570. You should get one and try it out yourself. Can't beat the price.
Forgot to post the numbers. The caculator says 77.1 mph and 7.7 lbs thrust.

Cool. Lucky Sevens.

MikeL@Sig

Hi Jeffie8696,

We are glad you like your Aviastar. We were finally able to get the pice down and we also think it is a great engine. You didn't mention the price in your post.

AVI46 AVIASTAR .46 2STROKE GLOW ENG EACH $49.99

Happy Landings.

Mike

jeffie8696

I probably was thinking nobody would believe me. [sm=lol.gif]. Mike can I thank you for selling such a cool engine. I have just started playing with it and the numbers I am getting are fantastic. I have some other brands of engines in this size and general configuration that don't even come close (not to mention they cost a lot more).

jeffie8696

Got several hours to play around with my .46 today and had a great time. I didn't get to try every combination in the book but I tried all I could before the neighbors started staring and making evil faces.
First the 10% nitro (SIG of course and 20% all castor) posted a best of 13,570 on the same MA 11X6 prop as the beginning of the test. That is good for 77.1 mph and 7.7 lbs of thrust.

Today I tried my same SIG blend only 15% nitro . I dialed it in with a Fox standard plug and another head shim, on the 11X6 it gave me 13,320. A few rpms shy but it gave me some breathing room for the rest of the testing. Still good for 75 mph and 7.42 lbs thrust.

Next up with the same setup came a Master Airscrew 10X6 that gave me 14,400. No surprise. 81 mph and 5.92 lbs.

I stumbled across an old Rev Up wooden 12X5 and thought hey why not, this thing has lotsa grunt. WOW gave me 11,600 ! that is good for 54.9 mph and a whopping 7.97 lbs of thrust. And it just seemed to turn that prop over so easy. ALMOST 8 LBS OF THRUST !!! FROM A .46!!!![X(] AND AT OVER 50 MPH!!

Next I went to the opposite end of the spectrum, this is where I fell into some difficulty. on a Master Airscrew 9X6 it turned a relatively steady 16,500 . Pretty good numbers but I wanted more. Still 93.75 mph and 5.1 lbs is a feat no other engine in my airdrome can match!
This is where I experienceD some detonation issues trying to push the envelope and so before I proceed I will be getting a couple more head shims to lower the compression since I really have come to love this engine and I don't want to hurt it . Funny I would have thought the bigger prop would give me detonation since the engine would be turning low rpms and high torque upping the cylinder pressure but the opposite came true.
I did try some SIG FAI fuel on the 9X6 and with an OS A3 plug it gave me the same 16,500. I really liked the way it ran on it too.

Since I performed the high rpm test I have been informed that this engine is engineered to make low rpm power (Oh Yea I noticed!! ) So small props are no longer going to be tested . That is cool, I love an engine that throbs out tons of torque and moves my plane around like a dragster. If I want the speed all I need is to dial in a lot of pitch, this bad boy will handle it.

jeffie8696

I just did a partial tear down inspection and I see no problems at all despite my thrashing. The top of the piston has a nice golden hue from the Castor that tells me all is well. Beautiful.

049flyer

My Feedback: (18)

What sort of idle were you getting and was it reliable? I have one of these engines and can't get the idle mixture lean enough for a reliable idle.

jeffie8696

I am still in the break in stage and I haven't been spending too much time trying to work on the bottom end yet. I do bleieve it is way too rich and loads up easy with the factory setting. And the all castor fuel I use needs a really hot plug to idle right. I will probably start to do some testing later this week. It just keeps running smoother all the time. I also have some idle bar plugs to try out, perhaps this engine will prefer them, time will tell.

049flyer

My Feedback: (18)

Well I pulled the carb off and reset the low end mixture needle visually. Then I started over trying to set the idle. I m down to about 1 turn out from closed on the low speed mixture needle and now the mid range is about right but the idle is still too rich to prevent a reliable idle for more than 30 seconds. It just loads up and dies.

I am running a Fox std long non idle bar plug but I think I will try a Fox idle bar plug and then a Fox miracle plug. I may try a Supertigre carb just to see if there is any improvement. I'm running 15% Omega.

For break in I ran about 70 oz of my break in fuel which is 5% nitro 29% all castor, same as my control line blend.

Top end is very strong on a Master Airscrew 11 x 5. Will post top end numbers whenever I get the idle set.

jeffie8696

Awesome. I appreciate any info I can get. The only fuel I have used is SIG 5/10and 15% nitro with 20% all castor so far. The instructions call for 18 to 20% all castor but we all know the great debate rages over castor versus synthetic. I remember I did try some SIG FAI fuel and it seemed to respond well, and it's 50/50 blended. Now that I think, I do remember mine wanting to load up at idle but I think I managed to lean it out to where it would transition OK. I hope to have time for some additional testing this week. I am very paranoid about air leaks so I use sealer on all my carb O-rings . Please let me know how it turns out.

049flyer

My Feedback: (18)

I am now down to 1/4 turn from closed on the low speed mixture and the idle is still rich, mid range is good. I am using 15% Omega and a Master Airscrew 11 x 5 prop. I have tried the following plugs: Fox Std Long, Fox RC Long with idle bar, Fox Miracle plug, McCoy MC59, McCoy 4 stroke plug. The hotter plugs give a better idle but too fast to get any reliability. Advancing the throttle causes the engine to hesitate, stumble and throw lots of smoke till it clears out then runs. Mid range to high throttle is good. Idle to high throttle is poor.

jeffie8696

Would you say the engine might still be really tight? I know mine was super tight when I first got it. Almost scary tight. I think the idle improved the more broke in it but like I said I haven't worked on the low end much. That is next on my agenda.

Something you might try. I noticed the other day that the muffler has no internal baffle. Perhaps the fuel pressure is fluctuating too much because of not enough back pressure in the muffler to pressurize the tank properly at low rpms. I recently installed a one way pressure fitting on my pressure line to the muffler and I think it gives me a more consistent flow.

jeffie8696

Today it is cold windy and wet. I ain't going outside to test nuthin. Sorry.

049flyer

My Feedback: (18)

After three days of experimenting and with some help from littlecrankshaft I have happened on a combination that gives a decent idle.

67 degree day
90% humidity
5% Nitro Ritchs Brew
APC 11 x 6 prop
McCoy 4 stroke plug

11,300 RPM high end with a 2700 RPM idle. Idle is reasonably reliable but not very reliable below 2700 RPM. Further running may improve performance. The low end is still pretty rich and I am not able to lean it further at this time, the 4 stroke plug keeps it running.

jeffie8696

Have you done anything with the head shims? It did make a difference in mine with the lower nitro.

049flyer

My Feedback: (18)

I've not changed any of the shims, running stock at this time. This engine seems to like low nitro fuels and hot hot plugs. I'm not getting anywhere near the RPMs that you are however. Probably would run well on FAI fuel. Maybe the tach is bad. I'll try again with another tach.

Very strong compression. Starts on first flip when cold and within 10 flips when hot. Still too rich on the low side for a good low idle, less than 2500 rpm. Maybe it will get better with more running.

So far I rate the engine as a good value and worth the money but be prepared to spend some time getting it tuned up. The needle valves were not set correctly out of the box. Not even close! I will make a note of their position and report later this week. The engine will be used in the club trainer and we are having an event this weekend so it should get plenty of running.

jeffie8696

I bet it's purring like a kitten by next week. I myself removed both head gskets on mine on the 5% fuel to get the best numbers. But on a small prop with high nitro it was over compressed with both gaskets back in, go figure.(on a big prop it was just fine) Luckily, head gaskets are cheap enough. What really impressed me was the numbers it turned on a big prop, I like the idea of swinging a big chunk of lumber cruising along with my trainer. You might find it likes FAI fuel also, I would love to be able to run it just to save money and extend the engine life. Please let me know what plane you use it in and how well it responds including props and fuel please!! I'm pulling for ya. By the way, I only used Master Airscrew props in my testing.

aviapilot

Please try a 11x7 which I found best for general sport flying.

For Aviastar Av-46, Av-53,Merlin #2003 plug works best for general sports flying. In case you need better idle , use Merlin #2011.

Sig glow plugs also work fine.

Enya #3 and #4 are also suitable.

In general, Aviastar engines runs better on fuel with castor oil.

jeffie8696

I believe I have an 11X7 Master Airscrew in my collection, I will give it a try and report my findings. I have no doubt that given it's performance with a 12X5 (11,600) it should be similarly spectacular. I have been trying several different glow plugs to see what effect it has. I am not familiar with Merlin plugs . I will obtain some SIG plugs and give them a test, SIG has 3 plugs listed( 001 002 and 003 ), what plug do you recommend.

aviapilot

A 11x7 flies a lot better . Aviastar engines focus on torque rather than high RPM. Shoot for about 10500~11000RPM on the ground. Too high RPM without enough oil will hurt the engine.

In the old days when we flew pattern, a 11x7 is already the prop for a 60~61.

As for Sig glow plugs, I 've used all three of them and they all worked fine ( depends on the nitro content of your fuel)

Currently I am using 15% nitro.

Merlin glow plugs are made in the USA. Here is their web site: http://www.merlinglowplugs.biz/

jeffie8696

aviapilot, I believe you about the torque this engine is making. My first propeller choice was an 11X6 and it did a great job turning it over.

jeffie8696

2fast. I have done some testing today and yes the idle is something that needs sorted out. I tried hot plugs etc but what I really think is happening is the main needle and the idle needle are in direct correlation to each other. If I turn the main needle counterclockwise I can turn the idle needle farther clockwise. I am starting to get much better idle and response now but I had to take a break to check the mail and it is a couple of blocks away so I will be sitting down for a while.
Dang it!! I somehow let a piece of crud get in my carb and now I have to start over. I was really starting to get a reasonable idle with good transition too. Back to the drawing board. It is getting a lot smoother the more I run it.

rainedave

My Feedback: (1)

Sounds like an impressive engine jeffie8696. But... It's not crossflow scavenged!

Seriously, I have been thinking about getting one of the .53's. They are nice looking engines and I remember when David Gierke was promoting (or importing) them a few years back.

Keep us posted on the idle fix. BTW, I might try a few of those Merlin plugs for fun.

David