Removing rod bearings from 218

[Dave72dt]

29 minutes ago, Sniper said:

I dunno, call me a snob but I's rather spend my tool money on real quality tools. Like Starret or Mitutoyo.  Yeah, they cost a bit more but are definitely quality tools. 

 

I would too, and have.  I was also making my living with them.  It was the style of caliper that I was pointing out and he probably doesn't need to spend a bunch of money on a likely one time build buying high end tools.  Cheap or not, they'll still be more accurate than the slide caliper for crank measurements.  A slide caliper is still a handy tool for quick measurements and it won't hurt him to have one in his toolbox.

[keithb7]

I bought some asian made micrometers. (not Mitutoyo).A 0-6” set. A dial bore gauge too. I really didn’t want to spend a lot. Possibly using them just for one engine overhaul. So I didn’t buy the best. Nor did I buy the cheapest. Sort of in the middle price range. I considered them to be part of my education costs. There’s no local course to take for rebuilding Mopar flatheads. I invested in myself and learned a ton. The tools allowed me to really dig in and find, and understand internal engine wear. Thrust and combustion forces. Uneven wear patterns. Etc. I measured everything I could, many times and gained a ton of experience. I researched why parts were wearing as they did.  The tools really knocked it home in my pea brain.  Proving the wear patterns. 
 

High quality tools are nice to have but not necessary. If you have time, scour garage sales and auto swap meets. You can find quality tools for great prices. That’s a bonus. 
 

I have found that I reach for my micrometers for other work quite regularly. They get used in my shop. The dial bore gauge? Awesome tool to own but it might, maybe, see one more use in my lifetime. I do like rebuilding engines. Who knows? Another opportunity may come along. 

If I recall (double check to ensure) your  rank rod surface is in the 2 ⅛” range? Buying 1 single 2-3” micrometer would get you what need today. It won’t cost much.  Then you get to learn how to read a micrometer! Fun times ahead. 😊

Edited April 11 by keithb7

[Sniper]

Well, maybe if he bought a set of real good standards to verify his readings then it might be ok.  But when your measuring things whit thousandths or ten thousandths of an inch tolerances, cheap stuff probably isn't up to it?

[Hickory]

Here are my homemade buttons

[Cooper40]

So let me get this straight. In order to find out what size bearings I need, do I need to measure the diameter of the crank journal with the micrometer or are there other ways to find out the size? I knew I needed to get a micrometer but I'm not sure what to measure with it ha! Totally new at this I want whatever micrometer I get to be good but I'll probably only be using it for this one measurement, put the bearings in and that will be it for now. Also, doesn't it say the size of the bearings on the back of them or no?

[Los_Control]

Myself I'm the guy that wants not the cheapest tool, but am looking for things that might be well built at a reasonable price.

I will need to get a ok set of calipers in the future, I plan to use them so little I would not spend a lot on them.

 

Important to measure piston cylinder wear. They typically wear in a egg shape .... As the piston goes up and down, the crank exerts pressure to the cylinder unevenly as it goes around. What you are looking for is consistency. Trying to figure out how badly worn the cylinders are ...... People like to set the ring gap differently for different reasons.

So if your tool is a couple thousands off, it is no big deal .... Total accuracy is not important here for checking .....

 

I'm not even going to take 3 seconds to look, I bet there is a machined block of metal available cheap, to test accuracy of your measuring tool. Just a piece of metal for a couple $$ designed just to check accuracy of your tool.

 

So same deal, the end goal on measuring the rod & main bearings. You use the plasti gauge  and measure the thickness with feeler gauges.

What you are looking for is consistency from one crank journal to the next to decide if you can use it without machine work. You are allowed a few thousands play .... If one journal is 15 thousands out from the rest ..... you just know it will not work .... does not matter if the cheap tool is one or 2 thousands off .... you are just checking.

 

So my thinking is, I can use cheap tools at home and decide if I can do a quicky ring & bearing job at home. .... I'm looking for consistency not accuracy.

 

If I decide that the measurements just wander to far out of tolerances and I need a machine shop to straighten it out ...... That MOFO better have over $6k in measuring tools.

Because he does it for a living and sells his service as a product.

 

 

1 hour ago, Cooper40 said:

So let me get this straight. In order to find out what size bearings I need, do I need to measure the diameter of the crank journal with the micrometer or are there other ways to find out the size?

Any competent machine shop will stamp the size on the piece. For example bored cylinders the pistons will be stamped telling the size of the bore.

Same with crank, I have a engine that was turned 10 thousands on main & rod journals and it is stamped 10/10 ..... it is in a very obvious place and easy to read.

[Dave72dt]

It MAY say the size if the crank has been ground before.  That however won't tell you if the crank journals are worn.  Each journal will require multiple measurements taken and recorded.  Keith probably has video of the process.  You may also want to watch a video on the correct usage of micrometers, how to read them.  Using them correctly will ensure an accurate measurement.

[Sniper]

40 minutes ago, Dave72dt said:

It MAY say the size if the crank has been ground before.  That however won't tell you if the crank journals are worn.  Each journal will require multiple measurements taken and recorded.  Keith probably has video of the process.  You may also want to watch a video on the correct usage of micrometers, how to read them.  Using them correctly will ensure an accurate measurement.

 

Problem is, I don't think the OP is planning on having the crank machined so it really doesn't matter. In which case two options apply.  Don't worry about and leave the bearings alone or just put new ones in the same size as you have.  Neither is optimal

[Los_Control]

25 minutes ago, Sniper said:

Problem is, I don't think the OP is planning on having the crank machined

Thats fine but measuring is still important. If the op finds a journal wore more then most, I suggest taking a break and drink a beer.

Then the beer can can be cut up to make shims to make the bearing fit tighter within specs ..... You will never know if not measured.

 

Again if the tool is a 1 or 2 thousandth off, we are concerned with how many shims are needed behind the bearing .... not the accuracy of the tool.

The more beer cans needed to be emptied to complete the project ......

[Sniper]

The 230 I bought to build had shimmed bearings, never saw that before.  Plastigage will do that for the OP, no need to spend money on calipers.

[Dave72dt]

OP's first post mentioned flaking on the bottom shell of # 6 so I don't think he's going to be able to just leave them alone and since the engine was stuck he may need to go further in depth.  The visual inspection is the start.  How far the OP needs to go can be determined later.

7 minutes ago, Sniper said:

The 230 I bought to build had shimmed bearings, never saw that before.  

 

You've led a sheltered life.  There's a lot of things that were done to salvage engines years ago that people shudder at today.

[Los_Control]

7 minutes ago, Sniper said:

The 230 I bought to build had shimmed bearings, never saw that before.  Plastigage will do that for the OP, no need to spend money on calipers.

While I say it jokingly, it certainly was a thing.

 

I'm just saying to @Cooper40 cheap tools may be fine here ..... just do not make them too cheap & junk.

At home we are just checking for consistency, the machine shop we are paying and expecting 100% accuracy.

[keithb7]

Not all bearings have the size stamped on them. 
 

If I were doing this I’d first of all get a paint pen. Draw an arrow on each rod cap pointing towards the front of the engine. You can number them as well just incase they were not stamped at the factory. Its so vitally important the caps go back on properly. If an oil hole is covered up by improper cap placement, you’ll be mad at yourself when the bearing starts knocking. 
 

The micrometer, if needed can be used to measure each shiny rod bearing journal on the crank. Measure each journal 3x. At each outer and, and in the center. As mentioned write down your measurements. You’ll get fumbled up a few times and think holy! That one is way out of spec. It’s likely your mistake when reading the mic. You are not doing the actual machining here. So a machinist grade micrometer is not required. You are measuring to ensure you get the right size replacement bearings. 
 

I looked it up. A new 218 rod bearing journal is 2.0615 to 2.0625 “.  If they have been ground down you’ll come up with a smaller number than this. 
Max allowable taper or out of round of the journal is .001”. 
 

Rod journals are often ground .010, .020, .030 down or more.  When I rebuilt my engine the surfaces were stock size still. True and even wear. I found a set .001” bearings on ebay. Designed for when just a polish is needed. I bought them and that’s what I told the machinist to do. He kinda a tweaked a little saying “it might be hard to get just .001 off the journals”. He did. The clearances turned out great.  Great oil pressure! 
 

When installing new bearings make very, very sure they go in place properly. No oil holes are blocked.  Re-install caps exactly as they came out. Be sure the lock washers are re-installed. Torque nut to 80-85 ft lbs. 
 

A Fowler brand mic on Amazon is not the cheapest junk. Not too expensive either. It’ll do fine. 

The principle here is they mill down the crank journal  so its diameter becomes smaller. Then they make the bearings thicker by the same amount. So the crank is undersized, the bearings are oversized. 
 

This job is considered a major intervention. You are basically performing open heart surgery on your cars major component. Think it through. Pay extra attention. When in doubt, stop. Re-evaluate. If you make a mistake the engine may have to come out.  At the minimum the wallet comes out. 

Sounds like an idea for a future video. Measuring your crank! I might do that. 
 

Keith

[Cooper40]

@keithb7 Thanks Keith for the in depth response! I've been watching some of your videos. Very informative. Also what you just wrote really clears it up for me. I will definitely take my time and go slow throughout the whole process.

When i have time (and the weather is good lol) I will go out and measure the bearing journal's and see what measurement I get. I'll paint mark the caps first. They have numbers stamped on them but I'll still paint mark them.

For the micrometer, would something like this work? It's within the 2-3" range. It says it's accuracy is 0.001. Not sure if that's good enough? What do you think?

https://www.amazon.com/Fowler-Micrometer-52-240-003-1-Measuring-Graduation/dp/B00B5HET36/ref=mp_s_a_1_1_sspa?crid=1WSH043D7EHX9&dib=eyJ2IjoiMSJ9.uKgulDy-BlaOFuK4TdIfHJl6t4veDc6LtI9yM0EyghYXQFmi1zQ5g2PxWHm1hogDSeFHsBUxLlI_-E_ekLgQZTsxz58AkCmpEnc-LWm6oX2zD5SIMhEGMZorb3UEm_OnNqUMjLOKGaA7qpBExputn4ixX8s0OJCON7xeLXmN95rQcHegnvCoE3pcu54B1rCUONNHCfxcxAoI9BQnzpTjQg.VEJzohbgH-029rCeJ8QjS5O2t6dF5xuf44G7rIg9BUg&dib_tag=se&keywords=fowler+micrometer&qid=1712922190&sprefix=fowler+mic%2Caps%2C91&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9zZWFyY2hfYXRm&psc=1

 

Thank you again for the informative response! 

[keithb7]

It measures down to .0001, one 10,000th of an inch. Its accuracy is 2 10,000ths of an inch. It comes with a 2” calibration spacer.  That one would be fine for me. 
 

If someone ground more than .0625 off, you’ll need a 1-2” mic. I doubt it  is that even an option?  Measure several times at the same spot. You’ll need to practice your technique. You’ll flub up. I know I sure did. Many times.  Get the pen and paper out and a calculator. Scratch your head a few times. I did! 

[kencombs]

On 4/10/2024 at 6:05 PM, Hickory said:

I roll bearings in about 15 times a year in the diesel world. For a special tool ive made my own buttons for work. Not sure if it would work in your car or not. I take a bolt and grind the head to the thickness of the main shell with rounding a slight arch. Then install the button into the oil hole on the crank and slowly turn the crank with a ratchet on the front. The button pushes against the main shell and rolls it out. Maybe at work tomorrow i can take a picture of one i made.

At one time those tools were available at the local parts store.   The 'head' was at a slight angle to match the oil hole angle and lay parallel to the crank surface.   Back in the day, there were a lot of 'in car/truck' overhauls.   Valve job, bearings and rings.   Mains were really common on Ford Y-blocks.   Most sixes didn't need mains the first time.

[Cooper40]

@keithb7 Sounds good. I'll get that micrometer and wait for a good day weather-wise to do it. 

[Cooper40]

@keithb7 Just pulled out the #1 rod bearings. Here's some pictures. Looking pretty bad 😬

We are trying to measure the crank with the micrometer and we aren't sure how to make sure it's in the center of the journal. It's really hard to see if it's centered properly. I want to be as accurate as possible. We got some measurements, one being 2.0625 I think?? Here are pictures of the measurement. Thoughts on how to measure it more accurately while under the car? Lol

We think the crank might have a taper (thicker in the center than on the edges).

[Dave72dt]

I'm getting a 2.0615 reading.

[kencombs]

Being in the exact center is not important as you need at least two measurements anyway, preferably 3 along the axis of the journal and 2-3 more 90 deg from that.   The bearings actually pretty good, other than staining from long storage with acid containing oil in it.   Normal acids from blowby.  

 

If in doubt of your measurements and/or clearance, clean it off and put it back on with some Plasti-gauge and remove all doubt.i

edit: I agree with your measurement on the first pic, can't see the second well enough.

Edited April 27 by kencombs

[Sam Buchanan]

41 minutes ago, kencombs said:

   The bearings actually pretty good, other than staining from long storage with acid containing oil in it.   Normal acids from blowby.  

 

Ken, are you sure about your assessment of the bearings? They look pretty bad to me, lots of erosion of the surface if I am interpreting the photos correctly. The second photo seems to show bearing material wiped across the oil hole.

Edited April 27 by Sam Buchanan

[Cooper40]

@kencombs I can catch my fingernail in both bearings. They seem pretty bad to me but these are the first bearings I've ever seen lol. 

[Cooper40]

47 minutes ago, kencombs said:

I agree with your measurement on the first pic, can't see the second well enough.

The second pic was part of the first pic. I was showing that the 5 was lining up for the 2.0625. 

[keithb7]

Appears to be stock size rod journals.  Looking at the bearing shells shown I agree, acid corrosion. That engine was likely sitting for a long time with old acidic oil in the oil pan. Some dirt or carbon has scored the bearing. Pretty normal stuff. The crank journal in the background of the one photo looks nice and clean. Measure more, see what you've got across the six rod journals. Can you feel any ridges with your fingernail as you run down the length of the shiney smooth rod journal?  You're 1/6th of the way there on making work scope plan.  I'd likely already have decided to not put those rod bearings back in.

[Dave72dt]

If you're catching your fingernail on them, it's definitely time to replace them.  If you were to run them again, I think shortly you'd see them flaking material off and damaging the crank.  Bearings are way cheaper than regrind plus bearings.  You'll need to drop a main or two also.  Those will also probably look as bad.