Originally Posted by Tango
Hey Cadillac...kwik kwestion. I have always been told that wet sleeve engines like the DT's should never run any water at all...only coolant, to prevent cavitation. Is this something you know or have heard?
Sorry if this is hijacking. The reply is a little late; I haven't been on for a couple of days. Prolly deserves its own thread. I don't have a bus yet, but I did read up on this when I first got twitterpated over the idea of replaceable cylinders.
I still think they're a pretty good idea, but:
Yes, there is a lot of chemistry/additive stuff you have to keep track of. Dip-strip testing and the like. This is because:
1) Wet sleeves are cylinders constrained only at the top and bottom typically.
2) Diesel combustion is basically repeated explosions.
3) this causes the wt sleeve/cylinder to "ring"; change its cross section to oval in one axis then the other.
4) They are really stiff, so their resonant frequency is really high.
5) This causes cavitation - the water can't get out of the way and flow back in fast enough, so little vacuum bubbles are constantly forming and collapsing on the outer surface of the wet sleeve.
6) Unless managed, this behavior will chew up sleeves toot suite.
7) It's managed by Better Living Through Chemistry.
So yeah, filters and test strips and vials, oh my! OTOH when/if it goes south, you can rebuild it in-frame for $2K and a couple of weekends.
Hope this wasn't too long.