300+ rebuild

[Freightrain]

Sealed bearing probably got warm enough to finally dry the grease out and burnt itself up.

I used to run a bronze bushing in my race car but it would hog it out crazy.  Switched to a sealed bearing and it has run decades without issue.  The metallic disc is surprisingly smooth release.  Though it only has 200# base pressure with 11 grams on each lever and a couple turns of base it has maybe 1200# at 6500 rpm.  Easy to drive around.

The metallic disc in my one hot rod was brutal to drive.  Smooth backing out of garage, then it would get chattery and be horrible to get it to start out smooth.  Either try to stall or I would just wind it up and go and then spin the tires.

The race car has a solid hub but hot rods have sprung hubs.  You made a comment early Geoff about encapsulated springs.  I used to have those in some of my old sprung hub clutches.  I guess it is suppose dampen the spring?  I would get a year before I would rip the center hub out of the disc.  It would rip the pedestals apart and the plastic on the springs would be hammered.  Thus switching to solid hub design.

[Freightrain]

After about 3 hrs the other night I have a pile of clean bolts.  I have a heated sonic cleaner with degreaser in it, run each batch for 1/2 hr and they came out pretty clean, then off to the wire wheel.

Head bolts, front cover, side covers and few misc. pieces all ready for assembly.

I am taking today off, have an errand to run and then off to get dry ice. I put my old electric heater under the block and turned heat up in garage so by the time I get home later this morning it should have the block warmed up some.

I'll report back later today with progress.

[Geoff Weeks]

Larry, I ran solid (un sprung) hub when I was doing heavy haul, hard on the input shaft but will not break and cause a problem pulling an oversize load. Once I finished doing those loads I went back to dampened hubs. Much easier on the input shaft spline.

I had been told that Detroit's used undampened due to their overlapping power strokes, there was pretty much a constant flow of torque through the shaft and no need for any springyness. 

[Freightrain]

Tadaaaaa,

We had a hammer ready but they slipped in effortlessly.  Nice.

Onto piston and rods.

[seyser]

Awesome! Glad it went well. 

BTW - I like your garage/shop. A true working mans shop, I'll guessing every engine part on the bench or shelf has a story to tell.

Keep the photos coming!

[Freightrain]

2 hours ago, seyser said:

Awesome! Glad it went well. 

BTW - I like your garage/shop. A true working mans shop, I'll guessing every engine part on the bench or shelf has a story to tell.

Keep the photos coming!

Most stuff is broken junk I haven't thrown away yet.... 😆.  After collecting for 40 yrs I am starting to pitch stuff because I don't have plans on needing it.

[Joey Mack]

I bet you will need one of those widgets 2 weeks later... 🍻 How do I know..?

[mrsmackpaul]

1 hour ago, Joey Mack said:

I bet you will need one of those widgets 2 weeks later... 🍻 How do I know..?

Yep

[Freightrain]

I also ordered a lower gasket kit from a place in Florida.  $79.  I didn't even call Mack to see what they wanted.   Should be here first of the week and by then I should be able to button up the bottom side. 

[davehummell]

Back in the dark ages I remember paying $5.00 for a Cummins oil pan gasket for my 220  

[Freightrain]

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.

[Freightrain]

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?

[Joey Mack]

One thing I remember is that liners have a .002" crush when installed. That said, i never measured the pistons, when I had correct part numbers. As far as wrist pin bushings go,  i do slide the wrist pin in the bushing with light coating of oil. I guess i developed 'the feel' for the fitment. I beleive the clearence fro them is .0015" .  

I hope some of this helps, 

[Freightrain]

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.

[Joey Mack]

Im glad you got the correct specs, and glad I didn't post incorrect info.  Im working from memory... looking forward to the video of it running like a clock.