Russian VA .020 engines

Just bumping the thread to hear how others are getting along with these fine little engines?

I have now made a new clamp in order to fit larger head buttons. I also added two cooling fins to it, just seemed like a good idea to have some on the head too. The Turbo plugs are a little large at the "tip" in order to fit a proper squish band, but below is my first stab at it. I made the head so that it sits a little lower than stock (about one head shim) and test ran the engine today with 3 shims in it and 10% nitro fuel (and a graupner 5x2 prop). Feels fine and I can try with less head shims later when I get to do some proper bench runs. It is a little tricky to measure the "deck-height" on such a small engine so I go more by the feel when I turn the engine over and how it runs. Feels like two heads shims might be about right and the stock head is probably not that low on compression after all. Or possibly this is a second batch of engines and they have increased the compression ratio compared to the first runs.

Next step will be to fit a header and muffler. The exhaust-flange was not drilled and tapped on mine, so I have now done that. Tapped it for M1.5 which looks about right for the engine I think. Everything is very small though, I feel like I have reached some kind of limit in terms of what sizes I can machine while still keeping some kind of accuracy...

Excellent effort Kris what sort of rpm are you getting with the 5x2?

I haven't checked the rpm yet. I just ran it a bit in the garden to see how it would needle and to check the head temperature. There is about half a turn on the needle when going from a rich setting to a leaned out setting, without pushing it too hard. It sounds quite happy and I'm guessing it will at least match a good Pee Wee in terms of power but a with much better handling. It might be even happier on a smaller prop though, the timing of the exhaust looks high and there is also a fair bit of SPI.

I haven't been able to get the conrod off from the crankpin, a little embarrassing but I really don't see how they managed to put it together. The .049 MkI had an adjustable piston height, and I would have liked to see how this one is made...

Kris, i thought there were shime that came with it. I'm thinkink it's the same construction. I wanted to run mine yesterday

Yes, the engine came with some small shims that looks like they could be for the piston timing. I'm not able to get the conrod off from the crankpin, and I don't want to force it.

I just found another reason for why some of these engines might be low on the compression, I have one head that leaks a little at the insulator. This plug I haven't even used yet...

Hopefully I can use the Turbo plugs instead.  

S kris

long time ago I had problems and fortunately some old guy schooled me that some glow plugs leak

he taught me to install, tighten just so much... drop of fuel on the plug... and look for bubbles at the copper gasket or, as you show, the center pin..... amazing how many leak

On a large engine it doesn't matter too much, some people even start the engine with a loose plug, only to tighten it once the engine is running. On a .020 engine I think it will matter more, and I don't recall ever having a cox glow plug that leaked at the insulator. If they leak at the gasket one just have too polish the sealing surface of the head a little with fine emery cloth (on a flat support).

I am actually thinking ...due to costs.... if my plug leaked there
I would ultra sonic the bugger...de-grease well...dry.... and seal with CA

of course in a sec someone will tell me CA won't take the heat

Either that, or perhaps the fact that CA doesn't work well on metal...

I am not too sure, seeing the leak you photoed, and a clean surface That a dollop of ca would not work to add to the crimped intended seal...agreed not ideal and if we were back in the .95c per plug days, I would not even consider

Too Fiddly ....but a HOT flow of J&B weld down into the crevice would certainly work...just too little and too messy

My CA thought was cuz is watery easy flow viscosity and the stuff is pretty tough

Are these little engines still Available ?

Kris,
Way to go with your developmental work !!!
Can't wait to see your results with details like prop, fuel, rpm, etc.
I don't know if CA Gel is available to you at home.
I get the original "Super Glue Gel " two each 0.12 oz /3.6 gm tubes for a $1.00 at our local "Dollar Store".
I find I use it most of the time since the watery versions make a great mess on me and my work.
My grandkids call it " Cragle" short for crazy glue.

Keep the good work !!!!

Steve............

akjgardner wrote:Are these little engines still Available ?

Who knows if or when another batch of these engines will pop up.
The NY importer sold about 80 or so with the BIN on eBay in a short period of time.
Looks like the US supply may have dried up unless another importer may have stock.
It may be that the engines dribble back into the market over time.
We'll probably never know how many VA actually made of the .020, the .049 MK1 and MK2 types and what amount came to the US....

Steve.......

fredvon4 wrote:That a dollop of ca would not work to add to the crimped intended seal...

Yup, the glow element well is a very small place to work in. Unless attempted from the outside, greatest difficulty I see with using CA is the possibility of getting the glow element coated with it, contaminating and ruining it.

Regarding return of VA production, wasn't it the Northern Velocity factory in Russia similar to Fox Manufacturing, makes most their money making small parts for other manufacturers, and the hay day of model engine profitability has passed its prime?

I don't know the full history of the VA engines, but I believe they were made on a small scale by Valentin Aloshin (hence the VA name), he was one of the two people that once made the STELS engines.

I have a DIY header for mine now, and gave it a little bench run in the garden with a sort of DIY muffler.
Used a cox 4.5x2 (stiff) in order have a comparison the cox .020 engines. I used my regular fuel which is 20% all castor and 10% nitro and I got the following numbers:

small intake venturi; 16200rpm
large intake venturi; 16400rpm

small intake venturi and longer header; 18800rpm

The large intake venturi will require a balloon tank though, the fuel draw is very weak on that one. I only just managed to get it running by raising the tank. The engine was behaving very well, and ran stronger than my Pee Wee engines, but it felt like the muffler was holding it back. I cannot run open exhaust at home though, so that will have to wait. When I lengthen the silicon tube between header and muffler I got an instant 18800 rpm on the same prop!

So there is certainly a lot of potential in these engines, well worth tinkering with!!

Here is the "longer" header set-up;

I have been trying to figure how one is supposed to get the piston out in order to change the piston shims. I cannot see any way to pull the big-end off from the crankpin when the cylinder sleeve is out. The only way I can think of is that one has to undo the top piston-part while the conrod is still on the crankpin (!). I have not dared to try it though as it would require some kind off clamp around the piston right were it is the most sensitive to any scratches...

Below is a picture of the construction on the .049 engine, from what I can tell the .020 has the same piston construction;

Kris there is a short write up on these engines here http://adriansmodelaeroengines.com/catalog/main.php?cat_id=0 says a guy (Maris Dislers) had been doing some testing on them , if you can get in touch with him maybe he can enlighten you us on hot the timing shims are placed . Adrian C. Duncan may can help?

Yes, I have seen that. Maris is also on RCGroups but doesn't seem to want to say anything on the forums...
I'm a subscriber Aeromodeller though, and will keep my eyes open for his review there.

In the meantime I'm fiddling along on my own, it's all part of the fun!

Thanks Eric for the good info about Adrian's Model aero engine site !!
I'll look forward to the VA .020 article !!!
Looks like Dave Acton must have sold off 80% of the total VA.020 production....
Glad I stumbled on the eBay listing to get myself one and give other CEF members a shot at something pretty rare..................

I adapted a pee wee springstarter today and tried the cox 4x2.5 prop, instant starts with the spring starter and it really screams on that prop.

Also tried a TD.020 but it doesn't have chance on the same fuel...

That's good news, what kind of scream are you talking about like 26K

No, I don't think so, it just sounded healthy and beat 20krpm I guess. It is handling very well, giving easy instant starts with the spring starter, and the needling isn't critical at all. After a good screaming run it is barely warm, not even breaking a sweat...

It is very sensitive to the muffler though, it has a lot of SPI and the exhaust timing seems long. Will try to measure the timing on it.

I checked the TD.020 today, it had a piston sitting fairly low and it was simply undercompressed, especially on the 10% nitro fuel. I took another piston cylinder set with the piston sitting higher and its runs fairly okey now I think. With cox engines I always seem to end up chasing the needle a bit, as compared to other engines that are more distinct through-out a run. I also shaved off a bit from the Turbo head that I've made previously (removed about one head shim from the sealing surface), and it now seems to match the stock head fairly well. Will try to get some tach readings next time I go to the field.