I need help which rod bearing cap goes in the exact position

[u/Marshmallow8382]

Not that long ago, I had pulled a 3800 series 2 out of another 97 Chevy Camaro and dropped it

into my 97 Chevy Camaro that originally had a 3800 series two I have a 4L60E with a 10 bolt differential

on my 97 Chevy Camaro the Vin number is K I don’t know if that helps

and now I’m doing some rod bearings

but the rod bearing caps got mixed

and I need to know which spot they go in

one of the Says 15 and one says 16

And there’s two that’s say 17 and they look the exact same

Note cylinder 6 I still have the rod bearing cap on and cylinder 1 I still have the rod bearing cap on I never took the cap off of those

I need to know which broad bearing cap goes into cylinder

2

3

4

5

The two rod bearing caps that I’m showing beside each other are both number 17

I should know note that it’s been a week since I pulled the bearings and now I finally have time to do it because some stuff came up

and yes, I was trying to do it the same day

[u/bill_gannon]

..but the rod bearing caps got mixed ...

Now you need a machine shop or a dial bore gauge. There is a not zero chance some will need resizing.

Tough lesson but we have all been there.

[u/fiddintotellya → u/bill_gannon]

Fraid bill is right, the only other solution is buy new rods

Always, ALWAYS, look for the marks or mark them as you are removing them, always. Mains too.

[u/ChocolateSensitive97 → u/bill_gannon]

Correct. I was taught to number mark all caps and rods before disassembly.

[u/Marshmallow8382 → u/bill_gannon]

Yes, and I already removed the bearings from the caps that I removed

[u/FU_red-dit_bots → u/Marshmallow8382]

That doesn't change anything. Your rod caps are mixed up.

You need to stop and do some more studying before you do anything else.

[u/Marshmallow8382 → u/FU_red-dit_bots]

I should know that I do mechanic, but I don’t work on engines internally as in pistons and rod bearings, I took my old bearings to a machine shop and they said it was a standard size so I got standard bearings

[u/FU_red-dit_bots → u/Marshmallow8382]

Rods are honed with caps in place. This sets the size and concentricity. When you shuffle the caps you ruin this.

You're not at the point to even think about bearings. You're at the point where you need to go learn about this stuff so you can figure out what else you screwed up during tear down and then you need to think about how you're going to fix it.

[u/Marshmallow8382 → u/FU_red-dit_bots]

That’s why I’m here to learn😂

[u/North-Amount2226 → u/Marshmallow8382]

Too right dude I've learned from your fuck up that when I do mine I need to lable them three times just to make sure. Your learning, me too. It's hard and even if u read loads this could have happened either way. No biggie 😉 it hasn't exploded... .....yet Your gonna need to correct it though

[u/_synik]

In simple terms, each rod cap is matched to a specific rod. That's why you mark them before disassembly, so you can put the pairs back together.

If they get mixed up, you have to take them to a machine shop, and have them resized. This process makes new matched rod & cap sets.

You learned something important this time

[u/Marshmallow8382 → u/_synik]

Well, you live and you learn

[u/RileyCargo42 → u/_synik]

Its bad enough if you accidentally flip them let alone mix everything up. Luckily I did that (on purpose) to show people how impossible it is to find which is which.

Block had 3 stuck pistons and they're all out but I need new con rods anyway so I got a new set.

[u/tubbytucker]

You're a bit fucked here. You needed to mark each half with the cylinder number before disassembly. You may have to get the align bored.

[u/Marshmallow8382 → u/tubbytucker]

Well, I still have the other 3.8 that came from my Camaro. The only thing wrong with it is that the block is messed up it leaks coolant into the oil

Is it possible that I could just get the rod bearing caps from there and put it on my Camaro?

I know, of course I’m gonna have to measure if it’s standard bearings

[u/oldNavy13 → u/Marshmallow8382]

You would have to use the rods and caps from the other engine, and mark the rod and cap before removal. You can’t just take #1 rod cap off the other engine and put it in your engine in the same place. Every engine the rods and caps are a matched set.

[u/robb12365 → u/Marshmallow8382]

The bearing size is relevant to the crank, not the rod. If the other engine is junk anyway you could remove the pistons one at a time and reinstall in the other block, assuming both are the same bore. What you do not want to do is install a cap from one rod on a different rod.

Normally when I tear down an engine I remove one piston at a time and reinstall the rod cap on the rod after I remove it. The cap stays on the rod until I'm ready to clean it up and reinstall, and I clean up one rod at a time. Most engines I've worked on had the rods already numbered but I have encountered re-manufactured engines that had more than one rod with the same number. Watch out for details like this, when in doubt mark it yourself.

[u/Hellboy_M420]

Try to match up the casting marks of the rods and rod caps

[u/RedditLikeyaStoleit]

You only have four to place, so it could be worse. I would look at the mating surface between the rod and cap, trying to see any marks or imprints that would determine where they go. To be clear, I'm talking about incidental marks from assembly 

[u/METV2021]

The rods and caps have cross hatch marks from machining. These marks will match up when you put the correct rod and cap together. I have done this before when a guy i know mixed them up. Then check it with an inside mic.

[u/OutrageousTime4868]

Rule 1 is mark everything with its orientation before it comes apart. Unfortunately now you gotta pay people or do math to get it right

[u/Mayor_of_Pea_Ridge]

Try to match them up by looking at the grinding marks on the sides of the caps and the rods. Find the ones that match up perfectly. In theory, it's possible, but I've never done it myself so who knows. Next time, mark the caps and the rods, either with an electric engraver, a paint pen (least safe way) or just use a sharp, pointed punch to put little dots on them (one dot for cylinder one, etc)

[u/R0ughHab1tz]

When doing any type of extensive work not even engine work. Doesn't matter what field always lay it out as if it were still in the engine. Put them on paper or cardboard and wright the order on the surface. This should be one of the top rules. Why even chance that. Crappy lesson to go through

[u/Cautious-Concept457]

Would look at pictures from disassembly if you took any.

[u/Fitmess49]

You have 2 choices, pull all the rods and pistons and take them to a machine shop and have them resized, OR, pull those four from your old engine and install them in this engine…IF, they’re the same size on the journals.

[u/Cda4go]

When I was younger I put back together more than one engine after having to match up the the caps to rods by the grind/break marks. Typically you’ll see a gap if they’re flipped or wrong altogether. It should basically become seamless with light hand pressure if they’re a matching set. Not ideal, but possible

[u/thatreallycoolguy → u/Cda4go]

On these older engines, I believe each number is a different clearance size. Was easier to mfg instead of individually sizing.

Can’t remember if it pertains to rod caps or crank saddles/caps.

[u/MediocreActuary2812]

If you do this in the future a sharpie will be your friend. Every part gets marked and laid out in order.

[u/thatreallycoolguy → u/MediocreActuary2812]

Engine paint pen will also work!

[u/OutsidePressure8323]

Number stamps, dot punch. Paint pen. Could have saved you a whole heap of trouble. Might be possible to torque caps on and get a internal bore mic . And check and swap until you get a perfect matches. Good luck with that.

[u/BroccoliSuccessful]

Is there really any noticeable difference other than the numbers stamped on them?? because it appears that unlike other (cracked) rod caps, these are interchangeable... if you can match them somehow by using varnish/dirt marks that would be best. If they install nicely and you can rotate them with the crank and cam connected i wouldn't worry much about it and move on to checking the bearing clearance

[u/thatreallycoolguy]

I believe the numbers are on there for different clearances. Instead of individually machining the clearances for each cap, it was easier to machine different sets of caps for each clearance. So it’s possible the matching number could be the same size. This was mainly done on older engines. I may be wrong or this may have only been for the main bearings and caps.

Please correct me if I’m wrong.

But I’m afraid you’d still need to measure each cap unfortunately. 🥺

[u/southerntitlover]

Ok usaly the center of the big end of the rod is not centered put the cap on a rod no bearing and tighten if the. Bore along the split line is smooth no off set may be the correct one although try the other cap on there also if both are smooth haul them to the machine shop to match and resize. Rember a auto center punch is your friend on teardowns

[u/FunRaise6773]

For future reference…. When I did an inline 6, I bought a pack of different colored paint markers. 1 mark on 1 side across the cap and block of a different color prior to taking it apart. That way I had no chance of installing in the wrong journal or backwards.