Dumb question time, of wrist pins & modifying pistons
Posted: Wed Sep 23, 2020 7:22 pm
This is probably more of a general engine question, although the 4A-GE uses both types of wrist pin attachment. From looking at parts diagrams, it appears that the early 18mm press fit wrist pins are pressed directly into the steel of the con rods. The later 20mm floating wrist pins ride inside of a bushing (aluminum-bronze?) that is itself pressed into the rods.
The question is. Should press fit wrist pins only be pressed into the steel of a rod?
If you could have custom aluminum-bronze bushings made, would it be a bad idea to press wrist pins into those? From some reading around the internet, it seems like that is, in fact, a bad idea. Would it be possible instead to have steel bushings made, in order to use a press fit wrist pin in a rod that was meant to accept a larger pin? Or to modify the small end in some other way?
And about pistons. Is it possible to have cast aluminum pistons, previously only intended for a press fit rod, machined in order to fit them with wrist pin locks (and use them on "floating" rods)? From one page I was reading, it sounds as though at least one of the Honda guys out there had this done for a set of his otherwise-stock (press fit) pistons.
The question is. Should press fit wrist pins only be pressed into the steel of a rod?
If you could have custom aluminum-bronze bushings made, would it be a bad idea to press wrist pins into those? From some reading around the internet, it seems like that is, in fact, a bad idea. Would it be possible instead to have steel bushings made, in order to use a press fit wrist pin in a rod that was meant to accept a larger pin? Or to modify the small end in some other way?
And about pistons. Is it possible to have cast aluminum pistons, previously only intended for a press fit rod, machined in order to fit them with wrist pin locks (and use them on "floating" rods)? From one page I was reading, it sounds as though at least one of the Honda guys out there had this done for a set of his otherwise-stock (press fit) pistons.