Freightrain

All 6 ready.... I played around with oilers. Not sure when I will get alignment tool so I think I will go off law of averages and get them all close to the same. I laid a straight edge across block, used a piece of .125 TIG wire and measured all the locations from top and side of bore. 4 were close to same, two needed some finesse. They are pretty close now within about 1/4" of each other's location. I assume it needs to hit the bottom of the piston(basically missing the rod end). Kinda up in the pocket behind the pin. Using an old piston I just eyed up where it looks best. Again, OCD is making it rocket science and probably was just fine before I moved a couple a little. I need to work on the rear seal install. The book makes it look crazy. Install housing the use installer to press seal in. Why can't I press seal in housing and then install housing? Don't want to screw this up either. Of course I don't have all the "installation tools" they request. I'd like to get pistons dropped in this week/weekend so I can get pan installed.

I spent some time last night discussing the details with my motor guy. He says "run it". So I feel pretty good hearing that. He doesn't do large diesels but does Duramax and Power strokes and it is all the same....just a bit larger. On with assembly.

We have a Sunnen hand hone at work that is basically the same as a stationary block hone. We use it to hone tubes at work. We have 6" long to 5 ft long extensions for it. We run it with a two handed 3/4" Milwaukee drill. I suppose if I covered up the crank well enough I could swipe a little out. But cleaning it back up would be a mess with the crank in it.

The good thing is all the parts are the same. No odd one out that is off the chart. The rings I touched up were likely fine but the feeler gauge was just a touch too snug in my opinion. I didn't have to do all, just a couple.

It is all Mack parts. My concern is the liners being almost -.002 undersize from book spec after installation. Why? Manufacturing? I had .0015-.002 shrink and the book calls for .001 clearance to .-001 shrink. It squeezed them a bit. Then the pistons being +.001/.0015 larger then old pistons. It all adds up to tighter fit. The book has a wide variation, so what is right? That is all I question. I have slipped pistons in the bore(had to to be able to check ring gap). They fit, it isn't that tight. Like I said, I don't want to gall a liner and tear it apart again. This is all just the anal "wannabee" machinist in me. I'm all for hacking shit that doesn't matter. Engine work is a not that.

I am just confused why feelers would be more accurate then using micrometers and a bore gauge. Both should give the same basic results if done correctly. Unfortunately I don't have long feeler gauges, as I have never had a need for them. I measured the old pistons and they are 4.867/4.868. Those were running on a bore of 4.875(on size and negligible wear). That gives it +.003 more clearance on average. Maybe I am splitting hairs but I don't want to have to do this twice! Thousandths make a difference.

Guess I'm confused....why? I bore gaged the cylinder and miced the piston. I have clearances that I question. Are you thinking I should use feeler gages?

I'm just concerned because the bores are -.0015/.002 undersize currently. It would have another .002 clearance if the bores were "on size". The new piston number doesn't mean anything to me and of course it doesn't match the 50 yr old book.

Im concerned about the new piston. What should the clearance be? Old piston is A-5213 562

Ok, can anyone tell me what piston I am using compared to chart in book? I am still questioning the clearances. I am in the .005-.006 range. Hate to find out I need .010!

Waiting to pick that up before installing rods. I wish the book gave you the dimensions as I would make my own. They just show a picture of it.

Chipping away. Have three rod assemblies ready for install. I had to file a few rings to get to minimal .013 ring gap. Might have been "ok" but I gave it a few more. Tolerance is .013-025. Last thing I need is to break a ring due to closure of gap. Yikes. Got front cover and side covers glued on. All bolts call for "nylon", so they got blue loktite. They had blue residue on the threads when I cleaned them. Using High tack on gaskets so they should never leak! Will finish cleaning the side of the block below the covers and around accy drive.

I'm just measuring because I can just to see what it is. Talking with my friend at motor shop, he says a 2" pin should have about .0015 clearance. It does. Piston is in range also in general terms. A thou one way or another shouldn't make a huge difference. I'm not "racing it" or turning excessive RPM. Gasket kit showed up just now. I also am going to get alignment tool for squirters just because. Will get pistons on the rods so I can get them shoved in after I check squirters this week sometime.

So here's a technical question. Book calls for bore to be 4.875. My liners had a bit more shrink then then needed and it tightened the bore a touch. 4.8735-4.873 (almost .002). Bottom of pistons are 4.865-4.866. The book lists like 4 different pistons and 4 different tolerances. From .0045 to .009 clearance depending on piston. None are what my part number is on my piston. So, is .007 clearance good? It's in the middle. I'm not familiar with big diesels, so I'm guessing it would be fine. Going by my mics, the wrist pins have about .0003 extra clearance. I think .0004-0007 is what it calls for. Just a quick check on pin bores all were right at .001. Something this big I don't see it as a huge issue. The rod bushing look near new. No odd wear patterns like the rods are bent. Those tapered bushings would be a PITA to replace and hone. Thoughts?

This has a lot of gaskets, not just a pan. Everything from below the heads. Side, front, pan, o rings, water pump, cooler rebuild, etc.