Some engine rebuilding questions

[stefan]

Do all of the bearing caps and plasti-gage at the same time....and see if there is any differences.
If nothing exceeds the 0.0015/0.0020 measurement...I would then measure the crank journals...if the journals are in spec...continue with the rebuild

If you mean do all 5 caps at once, thats what I have done every time. and there always all the same.

Also what kinda of tool do I need to use to measure the journals? you mentioned a micrometer but I dont understand how I would use that to measure it.

[jglutz]

This is a micrometer...some are capable of measuring 0.0001" or less.

If none of the old bearing had spun...both the bearing cap and the block will not have changed/worn. The bearings ar new. The only other thing that can be wrong is the Crankshaft journals...if they measure in spec...put the engine together...there is nothing else you can do.

Only other items I could reccommend; Is your torque wrench accurate? Do your have the right caps in the right position?

[stefan]

oh, ok.. you mean measure the crankshaft? I thought you meant measure the diameter of the block/cap, thats why I was confused about the tool. Ok, ill get that done.

I've always been confident in my torque wrench but I guess it wouldn't hurt to try another one, ill borrow one from a friend and give that a shot also.

I definitely have the caps in the right spots. It may have sounded like im hack because I mixed up the bearings, but everything else ive been preticulear about labeling. Also, if I remember correctly the caps are stamped with a number punch.

[stefan]

ok its time i got things rolling.

I got a micrometer, and the LOWEST measurement I could get is 1.9767

And haynes says 1.9661 - 1.9667

Now im really confused

[jglutz]

^^I would be confused too.
Can you post a pict of your micrometer.
What type of engine?

[stefan]

Here she is





I really dont get it! My crank is too big according to spec(), yet according to the plasti, its too loose.

Oh yeah, its a 92' 8-valve B6

[jglutz]

Great picture!
Good News and bad news
Bad news first...you're not reading the mic properly.
Good news...you look really close to where you need to be.
The dimension I read is.....
1 + 0.9000 + (0.025 +0.025) + 0.016
This equals 1.966.
Do you get it?
Now the fourth decimal place 0.000X (1/10,000 of an inch) comes from following the lines
on the left side of the barrell and following them to the right. Only one of these lines will line up with a line on the turning part (thimble). Follow the line back to the left and the number associated with this line is the fourth decimal place. I can not see this from the picture but I'm guessing it is 9 or 0 because you are so close to the 17 on the thimble.
So I read your measurement as 1.9669 or 1.9670
Take another measurement and work on your technique...amount of clampin force.
Once you think you have it....lock the mic with the wing lever...and try to remove the mic and reinstall it while locked onto the crank journal. After a few trys you will know if you are to tight or to lose. Once you think you have the correct amount of squeeze, take the reading.
This a very difficult task that take years of experience to be perfect...I work with people who do this every day and always ask to have their measuremnts double checked.

You're their...don't give up!

[stefan]

I was reading 1 + 0.9000 + 0.075

Because I can see 3 lines after 9, Is that wrong?

[jglutz]

It's not 75 until you pass the 25 on the thimble. Every turn is 25.

Form yetsredays post asking for the pict, I new this would be a problem, very common.

Here's some better text than I can provide

http://www.auto-met.com/mitutoyo/how_to_read_micrometers.htm

[stefan]

Oh, Ok! Thanks!

I just read how to use it on the internet, and the page said to count the exposed lines.. So thats where I whent wrong.

Anyways, I've been trying it more and I'm getting the same results (except read properly this time) Atchuley im getting slightly larger #s than the result pictured, becususe in that pic i had it tightened preety snug trying to get a lower #

So if my crank is well within spec, At this point im tempted to throw it togther.. Im not sure what to do. My clearence is way within the service limit so I dunno. This aint gonna be no race engine or anything.

[jglutz]

First and fore most....put it together

Secondly....take measurments every 45 degrees

Lastly...let's go...put it together.