Here are some notes on 3mm Venturi from Victor Yugov
Letter about Venturi from Victor Yugov
In the first half of September we had a great test of 3mm venturi.
Back in Poland, at the World Cup, we decided to run the last qualifying competition
Russian Cup with 3mm venturi. Competitors had three weeks to prepare.
Then we held a competition. Earlier I sent you video and results.
Now for the details:
-Each Team used its own fuel from this season. Experiments were mainly with propellers and venturi.
- Only three teams can get there settings to get 50 laps per tank (Dozidaev, Andreev, Shabashov). Speed in this case was 17.8-18.5.
Even Cherednychenko could not achieve more than 49 laps.
- Many teams experienced problem when engine starts up in the opposite direction. (CW instead of CCW)
- The teams of the second level were slow. Speed was around - 19 to 20 seconds.
- Everyone had problems with growth of carbon, carbon deposits.
- The sound of the engine is often not informative; it does not allow you to understand what engine wants. Nobody liked those races. It was not interesting. No satisfaction. More problems than it was with big venturi. This was especially for the second-tier teams.
Requirements to the motor, to its conditions have increased in comparison with the big venturi.
Later we had a test "standard fuel" of your prescription:
10% Shell Racing Advance M30
30% ether
60% of kerosene for lamp
1.2% DII2
Performance were good, the same as yours, and the same problem - the growth of carbon.
In early October, we held the Moscow competition (7 teams) with 3.5mm venturi.
Everyone loved it. The motors were working well. Our leaders reached speed of17.2s on easy setting with 40 laps. In the finals everyone were flying for 40 laps at a speed of 17.8-17.4 on easy setting. There were no problems for anybody.
After the competition we got together and discussed our impressions from engines working on 3.5mm venturi.
Overall opinion was: “It is what we need for F2C”. Everything became way simpler. At the same time the speed was quite satisfactory, we don’t need more, we don’t need less. At those settings and speeds both competitors and judges all have time to see and react.
Later we had a test on the venturi 3.5 with the "standard fuel."
Motor worked fine too - speed reached 17.0 at 40 laps. No problems, except for increases of carbon. But it was due to old oil Shell and lack Motul 800.
We came to the following thoughts:
- Official standard fuel is not acceptable neither for the competitors nor for the organizers as strongly complicate the competition organizing process, and perhaps now it is not needed.
- Motor with reduced air consumption (with venturi 3 - 3.5mm) becomes much less sensitive to the fuel. As a consequence there is no need to search for and use of toxic, dangerous, exotic fuel additives.
Perhaps now there will be not need to take kerosene and etherwith you on the plane.
Organizers can provide kerosene and ether at the side by requested by competitors.
The small amount of oil and DII is always possible to take with you in the baggage on the plane.
Looks like there's a big difference between the fuel combustion (burning) in the engine with 3mm venturi verses 3.5mm. With 3mm venturi on the rich setting for40 laps combustion (burning) is bad. For this reason, people are already looking for oxygenated fuel additives. This will complicate the F2C.
With 3.5mm venturi combustion (burning) is "right." Therefore, it may not need additives except DII in the fuel.
Here in Moscow weather has ended. We ask you to test the Venturi 3.5mm.
Victor Yugov