Testing new Engines and Models

Lerner and Profi against YOUGOV

By Contente - Goulão

Introduction :

After coming from the world Championship event, was obvious to us that, at least 6 F2C engines manufactures are in fact capable of good performances. They are :

Profi, Lerner, Zalp, Shabashov, Mazniak and Yougov. So we started to test some of this new engines.???, and compare them with the actual Yugov engine, to see what are capable to do !?!?!? Until now we have already tested two engines, Profi and Lerner and we have compared them with Yougov. Below some comments about this tests.

To start, about Yugov engine that we are using since 1999, This engine have suffer small modifications inside but not so much to provide an increase of performance, and for us the best yugovs are the versions from 1999, 2000, 2001, 2005, (the 2004 versions, the backplate is good), the rest have some problems in crankcase ,crankshaft, and backplates, also this engine has one week point,….  The piston pin. The piston pin rotates inside of the piston holes. This provide in theory a advantage because according with Yougov, this solution will reduce the movement resistance, and will increase performance and power… but in practical way’s this is an adjustment very difficult to maintain with the right adjustment. The problem is that after a few tanks 10 or 20 depending on the Pistons the problems start to appear.

Some engines with luck, does not sizure very much the piston pins, then when this problem happens is really difficult to get the engine open to have 2 or 3 hours work for 10 to 20 tanks run, and speed drop some times 1 or 1,5 seconds! Also we have sure that the Yugovs with the piston/liner adjustment more up are in fact better, and the problem of the piston pins decrease. Another problem is that Yugov suffer a chronic laps problem, (and that contribute also to the degradation of the piston pin), and that come because of the pin deterioration, the adjustment of the piston in the Liner (too tight), and crankcase to big!?!?(our opinion).

The Spanish Barragan have put a different piston inside the Liners ???!!!! that’s what they said, and the engine sounds very powerful, and is more tight then the original ones! That is the prove that the engine is still very good!!! They are using Kram model wish in our opinion helps also a lot!!

About models:

We tested several types and all seems more or less equal in performance, even the fashion of the retract system , for us is almost in terms of final result….. the same!!
About the other engines tested, we have bought 1 Lerner second hand, (Integral head 2004) and 1 Profi (standard liner) 2005 Gyula from Roberto and Marco Losi!
The test was made in the Bondarenko model with Mazniak tank for both engines!
First we tested Profi, and it's a fast engine, very strong, 16.6 to 16.8 top speed, and with a racing setting reach 17.0 ,17.3, however after came the first problems, the screws of the head are not strong enough to fix the head, (no integral head ), and the needle get’s lose from the body of the screw, also the drum give some poor adjust to the backplate these were the problems that appear is 60 tanks, however the engine remains fast.
A few weeks ago we tested a Kram model and the speed increase, Top speed 16.0, however we can go normally at 16.7, ( however we feel the need to make some adjustments inside the engine, in fuel and props), interesting finding is that the engine is durable !!!............

The Lerner was tested with the same fuel props and model, we find that, is a similar engine 16.6 (bondarenko model) was the same speed in the same model, however does not sound so strong , but we think that is because the engine is getting old !?!?!?
We think that at least this 2 engines are in fact very close, the differences are in the team !!!!.... Both engines give between 34 to 36 laps easily !?!

Engine conclusions:
The Profi and Lerner engine have at least one point better then Yugov in terms of race, when the engine overheat the speed does not drop so much, (this is a fact), regarding Yugov, the piston pin is an handicap. The Yugov engine seems better built appears to be much more strong in several aspects, but does not provide the same performance as the other two. However the Yougov construction is in fact much better and live longer, however in a lower performance !?!? Also a good characteristic in yougov is to be able to start well even same times to hot. This is an handicap is Lerner and Profi (hot starts)

Vorobiev in this last World Championship have used a tight piston pin in a Yugov engine, and according what we have saw the performance is equal !?!??!? so this is maybe a solution for yougov.

 

Preferences :

We think that the Profi is more easy to use, the crankcase is perhaps better then Lerner (they are almost equal, in fact they have the same fixation), and we think that piston-liner are very good two!!!
The Lerner have a good backplate and a good liner! but have a short life (piston/liners)

Yougov is stronger, he lives longer starts better but have a lower performance.

The tanks:
The better tank seems to be the Yugov tank, the Profi is also very good, the new Mazniak is good but heavy, the Lerner is for us the most difficult to use, the accuracy of start’s (at least for us) is not very reliable !?

In terms of models:

We consider the Kram models the best, light and strong (we also prefer Carbon to wood), However  the Bondarenko model are also very good, and the retract system for us is much better the the Kram system.  Kram model for Profi engine 310gr! (including valve, and prop).
- Kram model for Yugov engine 325gr!

Side View " Shape Comparison "	Frontal View " Comparison "	Side View " Shape Comparison, different angle "

- Bondarenko model

Is more heavy than Profi about about 15 to 35 gr depending  on the engine and undercarriage!
Both models are very sensitive to wind in the take-off, it is necessary to correct that characteristic! (our opinion).
 

Ours thanks for the support in this study:

Thanks to Roberto e Marco Losi, who provides us the engine Profi and all the stuff! Many Many thanks !!
Thanks to Roland that help us to achieve some different equipments !
Thanks also to Dick Lambert for the same and also in the last days for sent us the silver solder to solve the needle problem of Profi!
Thanks to Mazniak for all the help in some stuff he get us !
Thanks to Gordon Yeldham for all the " things...." !
 

Hope we have help your decisions in relation to this subject's not only for those that already have some experience, has also for all the teams that are starting now, and won't to understand what’s happening regarding this new engine technologies.

Ps: However do not forget that even using the best equipments a good team makes always the difference.

 Best Regards to all

 Contente and Goulão