I can see how it might work out that way for a clean sheet design, so I'm starting to slowly get what Piston Guy is saying. You need to hold some load, and that load amount determines both how much overlap you need and how large diameter pin you need.modok wrote: ↑Thu Jul 05, 2018 8:07 pmIt makes perfect sense IMO to go with a ratio. the length should be a function of diameter, Diameter should be a function of load...... IF you are making a lightweight design and a rigid piston.ptuomov wrote: ↑Mon Jul 02, 2018 1:02 pmThat probably works in practice. However, shouldn’t we rather state the minimum overlap requirement in terms of fractions of pin length? If we just drive it off the diameter, then would increasing pin diameter by 1mm and making it thus stiffer increase the need for overlap?
But how about, say, boring out the cylinder and retaining the same rod? Now the bore is larger while the pin diameter is the same. You'd probably want not only a little thicker wall pin but also a longer pin. Should the overlap between the wrist pin and the pin boss in the piston be increased? I don't know, but seems to me that the answer is yes.