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Russian VA .020 engines - Page 5 Babe_b10
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Russian VA .020 engines

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Post  Ken Cook on Sat Apr 25, 2020 8:26 pm

I would love a adapter with this. This engine is a neat little piece. I had 4 shims in the head today and it was running beautifully. It's begging to get on a plane.
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Post  1/2A Nut on Sat Apr 25, 2020 11:58 pm

Yes that would at least make a nice throw and go project, a turbo plug should give a bit more rpm.
A limited run of adapters for the VA .020 around 50 should sell off once the word gets out.

The last unmodified prototype adapter for TD .020 tested beat out a stock plug in my environment.
Back to back testing after cool down, there is a bit more design improvement that could be done to
squeeze out more rpm. It is by far best prototype to date: 18,249 rpm with a stock 4.5x2 prop!

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Post  Surfer_kris on Sun Apr 26, 2020 2:56 am

Ken Cook wrote:          I would love a adapter with this. This engine is a neat little piece. I had 4 shims in the head today and it was running beautifully. It's begging to get on a plane.

Yes, these engines are really great. Same build quality as the VA .049 MkII. Smile
It is a pity they didn't make more engines like this.
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Post  Ken Cook on Sun Apr 26, 2020 6:29 am

Kris, did you make your turbo head adapter from the existing glow plug? Digging through the posts, I came across my take on using a Norvel plug which I think I will try. I felt my rpm's were down compared to your stock findings but I did have 4 shims in place. Nonetheless for my purpose, the engine will have too much power as I only can fly free flight in a very small area.
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Post  Surfer_kris on Sun Apr 26, 2020 7:04 am

I made a new head insert (which takes a turbo plug) and a new head clamp from scratch. That way I didn't have to alter any of the stock parts. I made the head clamp with a little larger bore (compared to the stock one) and also added two cooling fins. The larger bore enabled a bit more material to be kept around the plug-threads on the head insert, as the thread of the Turbo plug is relatively large in these engine sizes.

It should be possible to modify other heads and inserts (in a lathe) and use that together with the stock clamp. I think AndyW (on RCU) used cox .020 or .010 heads for that purpose. There should be a thread on RCU about that, but it is probably about 10 years ago.

The power is really good for a .020 engine, but you could easily tune that down by using a smaller intake venturi. The thread on the intake is a regular M5 thread (i.e. 0.8mm pitch). Mine throttles fine so the engine timing works well at lower revs too. I imagine that one could make a "Texaco" version by simply using a smaller intake venturi. Mine came with two inserts, the larger one will require a pressure-bladder while the smaller one seems to draw fuel fine on its own.

Here is the stock head and clamp, next to my DIY version for the Turbo plug:
Russian VA .020 engines - Page 5 Img_1810
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Post  1/2A Nut on Mon Apr 27, 2020 3:15 am

Thank you Kris - M5 x.8 for the venturi.

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