Looking for recommendations on what to do with hurt cylinder

Measure skirts close to the bottom. Sounds like quite a bit of clearance for a cast piston IMO. Did you zero the gauge off the mic after measuring a piston skirt? If you're going off the supposed bore measurement on the gauge, it'll most likely be wrong
 
JWhite said:
Measure skirts close to the bottom. Sounds like quite a bit of clearance for a cast piston IMO. Did you zero the gauge off the mic after measuring a piston skirt? If you're going off the supposed bore measurement on the gauge, it'll most likely be wrong
Click to expand...

That's where I measured the skirts. I set my mics to 4.0185 and zerod the bore gauge off of that,then subtracted whatever the dial indicator read to get my 4.016 etc. Is that wrong?
 
Well it's not incorrect lol. If you trust the mic, should be fine. I can't see exactly what you did and how, so I'd just double check everything
 
thatguy69 said:
That's where I measured the skirts. I set my mics to 4.0185 and zerod the bore gauge off of that,then subtracted whatever the dial indicator read to get my 4.016 etc. Is that wrong?
Click to expand...

That is correct. Subtract or add depending on which size of zero the dial bore gauge reads.
 
OK fellas, double checked my bore measurements and 4.016-4.017 is correct. Haven't figured out what the spec for ptw is yet. Here is two attempts at honing the cylinders with 12 strokes on each attempt, 180 grit hone that's 4.1250". I'm wondering how much more I should try and attempt to clean these scars up? I can just barely hang a nail on them if I really force it.
 

Attachments

  • 20221231_213501.jpg
    20221231_213501.jpg
    427.4 KB · Views: 0
  • 20221231_213440.jpg
    20221231_213440.jpg
    410 KB · Views: 0
Did the scars get any better with the honing? Also did the bore dimensions change any?

As far as the honing goes, it looks like you either need to slow the drills rpms down or pick your rate of in and out. The hone lines look to vertical. Might just be the picture?
 
thatguy69 said:
OK fellas, double checked my bore measurements and 4.016-4.017 is correct. Haven't figured out what the spec for ptw is yet.
Click to expand...

Standard bore is typically 4.016" typically with 0.004-0.005" factory piston to wall clearance. On a cast piston in a street application I wouldn't be too concerned up to 0.008" piston to wall, plenty of higher power setups are in that range.
 
OK guys, getting back at this thing. Unfortunately the truck is last on my list of priorities financially and time wise so this is going to go a bit slow. Getting my bearings/gaskets ordered within the next couple of days. Does anybody know of a solid cam manufacturer that makes a 24v cam with the fuel pump lobe on it? I'd rather go that route so I can maintain the mechanical Cummins fuel pump for reliability/ease of replacement if I lost the pump on a trip vs running a fass or air dog.
 
You must log in or register to reply here.
Back
Top