How does a hydrolocking engine work

Saito FG 60 radial engine

Sorry, was not online for a while.

That you are asking me this question now surprises me a bit.

I'll try to be more precise.

A screw connection is defined when the screw is pretensioned to such an extent that it covers the entire area of ​​the operating force including the setting of the screwed parts.

There is also a video that is certainly not unknown to some. In this case, the mother is the aluminum housing.

https://www.youtube.com/watch?v=Go8C_kMeupw

In the case of the Saito, an aluminum assembly is screwed together with steel screws.

Corresponding tightening torques are defined for each strength class from e.g. 4.6 to 12.9. The higher the strength class, the higher the pre-tensioning force and the required tightening torque. However, if the strength class of the screw is too high, the aluminum components do not allow the preload at all, since the surface pressure between the screw head and the housing becomes too high and plastic deformation occurs, which in the further course leads to a loss of preload.

You can now make a compromise and tighten with a reduced torque, which of course restricts the function of the screw connection or, in the worst case, even leads to failure.

Or I take ("softer") screws in a lower strength class and thus a lower preload force, whereby of course the conditions as described above must be met.

Another approach would be to implement DA and use aluminum screws. DA certainly didn't just do it because of the look and weight.

Here is an article that deals with this topic and also describes interesting things about the course over time.

http: //industrieanzeiger.industrie....lten-besser-mit-alu- Schrauben/#slider-intro-2

Michael’s Post 258 is heading in that direction too. Loss of preload. What is ultimately the trigger, the borderline thread length or a combination of both, remains to be seen.
What I don't think is a cylinder that is too thin, as the majority have been using the drive without any abnormalities under the same conditions. The only variable on the drives is this area.

Meanwhile the FG 60 are partly with the addition revised version with the black nameplate
Applied. It's a shame that you won't find out about the changes. Saito wouldn't break a spike if they did some investigation here. The drive deserved it.