Don't hold back, tell me how dumb I am...

[JeffMoss1]

oh, also, how do I get the aluminum from the bearing off the hardened ground crank shaft surface? Anyone ever done that before?

 

[Mr_Roboto]

thanks a lot for the kind words guys...


I've inspected the caps and it looks like they're all on straight, but not matched up to their correct rods.

Thanks again guys

That's as bad as having them on backwards. Caps are mounted, then the hole is machined. So no two are the same. If you lose one the whole mess needs to be re-machined.

You can't do that on newer connecting rods, they are made of powdered metal in one piece, then "broken" at the parting line so there are two rough surfaces that fit together perfectly in only the proper orientation, and only with its mate.

 

[sle2115]

sle2115 yes i used 30wt oil...is that what you'd use?

30 wt is fine for oiling the cylinders, but I would use engine assembly lube for all bearings. It is a white, kind of slimy assembly lube that you can put an engine together with and it will be there a year from now. Oil will drain out. The stuff I used was in a white tube, kind of like a plastic toothpaste tube (can't think of the name right now) and was only a couple of bucks and enough to do a couple of engines.

 

[RLDSL]

thanks a lot for the kind words guys...

I'm exhausted.

Turns out a rod bearing spun. The rest look like they're fine...some very small scuff marks. I bought the plastigage already i'm gonna get to work tomorrow. I think i'll just buy new bearings...i don't think they were too expensive.

sle2115 yes i used 30wt oil...is that what you'd use?

Riot warrior...i cleaned all the carbon out of the grooves. I actually have the tool to do it with...believe it or not.

I've inspected the caps and it looks like they're all on straight, but not matched up to their correct rods. Main bearings are good though. I'm gonna go with that being the problem and I'm gonna try and prime the oil system this time.

I'll post a pic of it tomorrow when I'm conscious again. I've been working for like 24 hours straight.

Thanks again guys

Time to break out a micrometer and measure those bearing journals. If one spun, chances are the crank has been ground undersize sometime before.

For stuffing pistons, I usually soak the things in synthetic gear oil and pop them in. I've found it to let the things slide in easier than 30wt with the ring compressor good and tight so they go in clean and fast every time, plus it stays put longer if the engine is going to sit a while before getting into the vehicle.

------------Robert

 

[RLDSL]

oh, also, how do I get the aluminum from the bearing off the hardened ground crank shaft surface? Anyone ever done that before?

I've done it on a nice big machine built for polishing cranks plenty of times, but not sure how you'd do it there . You could try a strip of exceedingly fine grit wet dry sandpaper looped around the journal and wet it down and run it evenly around the journal kind of like polishing a shoe. and make sure to stop every few strokes to make sure you haven't picked up a big chunk that will dig in worse. don't let it dig in, brush across the surface.
If you don't trust your muscles to back off, might want to try a rag and fine metal polishing compound.

Is there any chance that the rods and caps were stamped with numbers to match them up by someone in a previous rebuild ?

 

[Michael Fowler]

Glad to hear its not all that serious!
I use crocus cloth to polish crank journals. A piece a little narrower than the journal about a foot ot so long. Wind the crocus cloth about 2/3 the way around the journal and pull one end and then the other ( like you dry your back with a towel).

 

[JeffMoss1]

If you lose one the whole mess needs to be re-machined.

So wait, if I find all the mates (caps and rods), do you think I can still use my rods? I'm hoping I can just redo this bearing job with polishing that spot on the crank and just assemble it back up without touching the heads or anything on top.

 

[Shadetreemechanic]

As long as torquing the incorrect caps on them hasn't warped them or the caps. Dry fit the correct caps with rods without the rod bearings and observe. They should nest exactly with one another without any lip where they come together. I would say if they look good you can reuse them. Some of these guys have done many more motors than me and might be able to offer more insight.

 

[ttman4]

You could try a strip of exceedingly fine grit wet dry sandpaper looped around the journal and wet it down and run it evenly around the journal kind of like polishing a shoe. and make sure to stop every few strokes to make sure you haven't picked up a big chunk metal polishing compound.

Is there any chance that the rods and caps were stamped with numbers to match them up by someone in a previous rebuild ?

Jeff, I've seen some rods & caps stamped with a small punch instead of stamped with numbers by previous overhaul person.
Ex: 1 punch mark on rod & 1 on cap, 2 punch mark on each, etc, etc....or some other way of marking. You might look for something like this.

I would think trying to get pistons & rods back in original hole is pretty inportant, but matching the caps with original rods is mostest-of-all important. Try what Shadetreemechanicsuggested or some of those things & maybe you can narrow down which fit what. Mic. & plastigauge.

Like the other guys said, Polish out with the crocus cloth or really fine (I don't know grit #'s, but let's say 1000 grit???) strips of paper or emery cloth that's long enough (12" or so)to wrap round & pull se-saw action. No finger polishing with finger & paper....get flat spots.

Unless crank is gouged it probably can be polished out.
Lots of good info here...lots of smarter guys than me too!

This is extreme, & not called for on your engine, but I spun 2 rod bearings & put pretty good gouges all round 2 rod journals on a 335 Cummins once in Boise,Id...gizillion mi from home, no money, house full of starving barefoot kids, pregnant wife......

Was in a shop tore down & they wanted more $$$$ than....well bunches of $$$.
I polished & rubbed & polished & fingered & polished till I got things back flat surfaced...still had below surface gouges, but surface was flat. I put new bearings in & ran that engine about 8mo. before overhauling.
PO'ed that shop off...they kept telling me it won't work.....tell the truth, I didn't think it would either. No $$$ call for extreme things....

 

[6 Nebraska IDIs]

Make sure that the crank didnt get jacked when that bearing spun.

Dont feel bad. I started working on vehicles when I was 6 and tell ya what still did stupid stuff when I was 17. And tell ya what, I still do. lol
You're constantly learning, chalk it up to learning and put R back together.

 

[f-two-fiddy]

I was buttoning up the fuel system, after changing heads on my 85.
I was getting stoked to get the air bled, and fired up.

I looked down on the bench, and what is laying there?

The lifter spider! DOH!!

$45 for another valley pan, and 3 hrs later. She fired right up.

 

[6 Nebraska IDIs]

$45? Thats CHEAP! They are well over $100 around here!

 

[f-two-fiddy]

Napa sells them for $66

 

[JeffMoss1]

all the plastigage turned out within spec. the wet-dry 1200 grit paper worked BEAUTIFULLY! That one bearing had a tiny bit less clearance than the others, but it was still within spec. So everything seemed to go together nicely, and the engine spins freely this time.

It's back on the motor mounts and I'm half ready to blow off thanksgiving with the relatives to start her up...but that would just be suicide.

So things are looking good. I'll start it up before the end of this long weekend.

 

[h2odrx]

WOOO HOOOOO!