Found loose shims & unused cotter pin in oil pan - What do I need to check? (w/pics)

[Laredo]

When I drained the oil this morning to do an oil change, a couple shims were poking out of the pan drain hole. I dropped the pan and found 3 used rod shims (had crimp marks on them) stuck in the pump spring and 1 unused cotter pin lying in the drip tray.

So....the question is where exactly do I go from here? I'm completely new to As and engine with babbitt bearings/shims. The guy I just bought car from said that he had put no more than 500 miles on the rebuilt original engine. I believe that after looking at the bottom. He had a counterweighted and counterbalanced crank installed, as well as a Model B camshaft. The engine ran great - no knocking or other odd noises, great power.

There was zero sludge in the pan. All connecting rod nuts have their cotter pins installed. All main bearings and connecting rods have shims present and seemingly tight - I tried pressing on each stack of shims sticking out of each rod, and none of them budged any.

I tried to wiggle each rod cap to see if there was any side-to-side play, and here's what I found. Rods 1 and 2 (starting from the front) were tight and didn't move at all. Rod 3 had the most play (although it was very little, I could see and feel it). Rod 4 had a very small amount of movement (I couldn't feel it but could only see the oil squeezing out when it did move). I have a video of it that I will post.

So what should I do from here? I've never checked any bearings with shims before. Is it necessary to do in my case?



Front Main:


Center Main:


Rear Main:



#1 Rod:


#2 Rod:


#3 Rod:


#4 Rod:


Shims found:




Any guidance would be appreciated.

[J Franklin]

If shims or cotters are missing take a closer look. Maybe they were just extras or someone had dropsy fingers.

[Bill Cilker]

Those are shims for the rods. I would pull the cotter pins on the rods and make sure that each rod bolt is tight. I would not tighten them more if they are already tight. If all is well, then I would assume that they were dropped while building the engine.
Are the shims single units or are they more than one shim in each unit?

[Laredo]

That's the thing - all of the shims seem tight and have no movement to them when I pressed against them. So I don't know whether I need to get into this thing to check it or chance it. The unused, new cotter pin makes me think the engine builder must have been a little clumsy or not paying close attention. Who knows.

Here's the video I uploaded of the side play:

https://youtu.be/7qduTKS6Wl0

[Laredo]

Originally Posted by Bill Cilker

Those are shims for the rods. I would pull the cotter pins on the rods and make sure that each rod bolt is tight. I would not tighten them more if they are already tight. If all is well, then I would assume that they were dropped while building the engine.
Are the shims single units or are they more than one shim in each unit?

When I first noticed them sticking out of the drain hole, two of them were still stuck together. It was only during removal that they peeled apart. And then the other shin was poking out but was separate from those previous two.

[Bruce of MN]

Sponsored Links (Register now to hide all advertisements)

Definitely save the cotter pin for use later.

[jack backer]

No rod knock? Sloppy engine builder..a brother mechanic used to say “parts left over? Toss’em in the carb, they’ll find their place”

[nkaminar]

Normally I would recommend taking the rod caps off and checking for the proper clearance, but in this case I would say to bolt it back together and run it. The fact that all the rod bolts have the cotter pins in them is a good sign. The sideways movement of the rod bearings is normal.

It is probable that the engine builder dropped the shims and pin when setting up the engine. They probably got caught in the pistons and when the engine was turned over and run for the first time, dropped into the pan. If they dropped to the dipper trays the rods would have slung then into the bottom of the pan.

[rotorwrench]

The dipper tray is sometimes difficult to remove but it can always be popped out of there. Perhaps whom ever did the last engine work didn't take it out to clean under there. Maybe they didn't know it will come out. Amateur mechanics don't always know how to deal with old technology.

[Patrick L.]

' clumsy or not paying attention '

That kinda sums it up. Maybe just me, but, as long as the pan is off, I'd recommend checking the clearances. I set them at .0015"

[Chris in WNC]

I agree, since it's apart check all clearances.
I'm not a fan of plastiguage.
Use the tinfoil go-no-go method.....

[katy]

Check the crankshaft end thrust while you're down there, hopefully it won't need adjusting.

[gdmn852]

Hello,as mentioned some side play is normal, the shim will only take up clearance between the diameter of the rod and journal.To check bearing clearance, you can use either plastic gage or shim stock, usually around.0015 is what you want.

[Laredo]

A few more questions for the group:

1. Since I only found rod shims in the bottom, should I only check the clearances on the rods? I know I'm already "in there," but I also don't want to open up a can of worms by fixing something that isn't broken.

2. Because of the castellated nut and cotter pins, what do you do in the scenario where you have obtained the correct clearance but the holes in the nuts aren't aligned for the cotter pin to go through? Do you tighten to the next hole and, as a result, make your clearance tighter, or back off to the previous hole and make it looser?

3. I'm curious about the accuracy of the foil method (as it's recommended) because I just used a quality Mitutoyo micrometer (accuracy verified with a standard) to check the thickness of the standard Reynolds aluminum foil. A single layer of foil is 0.0007", double layer is 0.0014" and triple layer is 0.0021". So the double layer that is often recommended to achieve 0.002" is actually too tight.

I can't decide between Plastigauge and the foil method. If I do the foil method, it definitely won't be with just 2 layers. I also learned something on this forum about using Plastigauge with a little bit of oil to avoid imprinting the babbitt. I have always read and been told that it should be using dry for accurate results, but, low and behold, the official Plastigauge website says to "apply a smear of grease to the journal and small quantity of silicone release agent to the shell" before applying the strip of Plastigauge in the next step. Learn something new every day.

[J Franklin]

.0014 is perfect. I use plasti-gauge. How long has the engine run since the rebuild? I really don't see much to worry about in your photos.

[Patrick L.]

1. It doesn't take much more to check at least the center and rear main.
2. Once you tighten the nuts and the pin won't fit thru, tighten the nut just enough to
stick the pin in. Don't back off on the nut. This will not change the clearance.
3. I'm not a fan of the 'foil' method. I use fresh Plasti-gauge.

[Benson]

Maybe the grandkids were "helping Grand Pa" and put these into the engine when Grandpa was at Lunch!!

[Laredo]

Originally Posted by J Franklin

.0014 is perfect. I use plasti-gauge. How long has the engine run since the rebuild? I really don't see much to worry about in your photos.

Including the test drive, I have personally only put less than 20 miles on it. The gentleman I bought it from said that he had not put more than 500 miles on the rebuild that he had a shop in Kansas City do.

[Laredo]

Originally Posted by Patrick L.

3. I'm not a fan of the 'foil' method. I use fresh Plasti-gauge.

I'm leaning toward using Plastigage. That's even what is recommended to use in the Les Andrews book.

[Laredo]

What size cotter pins do I need to get? I assume it's not recommended to reuse them. Is there a certain "type" (meaning, can I get them at Ace Hardware or do they need to be stronger?)