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Discussion Starter · #1 ·
http://www.network54.com/Forum/85220/thread/1135777857/
http://www.network54.com/Forum/85220/thread/1135305744/Ruined+Block-+How+do+I+check-
http://www.network54.com/Forum/85220/thread/1135691466/How+to+pressure+test+the+oil+pickup+tube-
http://www.network54.com/Forum/85220/thread/1120103248/How+do+you+'adjust'+your+clearances-
http://www.network54.com/Forum/8522...+the+motor+and+my+oil+psi+is+so+low,+should+I...
http://www.network54.com/Forum/85220/thread/1122692219/Very,+very+disappointing+day.+Suggestions-

For those that frequent this board, you're probably somewhat familiar with my situation. After losing oil psi on the Hot Rod Power Tour, I had the car hauled home and pulled the motor. Upon disassembly, I quickly realized a poly lock broke. Since the motor was already out and I drove an unknown distance without oil psi, I decided to freshen the motor. After getting everything back together and started, I had very, very low oil psi (about 5 psi) after a couple minutes of running.
The above linked threads are some of the questions I asked in an effort to find my lost oil psi. The motor found its way into and out of the engine bay 3 or 4 times without a change in results. Eventually, since the car only sat in the garage, I realized the block had froze due to the temperatures in my garage (don't trust a heated garage!).
I bought another block and recently took it to the machine shop. Over the next week, I completely disassembled my old motor and took my crank and a piston down to the machine shop. I stood around for a couple minutes so they could tell me what size bearings to order (I'm having the crank turned). When He said I needed to turn it .030" under, I questioned him because there was very little damage on the crank. He then proceeded to inform me that my crank was already .02" under.

The climax:
That's not what they told me when I had my motor freshened!!! I went home and double checked my rod bearings. I had .010" bearings in it! I assembled the motor with the wrong size bearings!

Although I've wasted so much time and money because of this simple error, I couldn't take the smile off my face last night. I'm just happy to know what the hell happened. Even with that big ole' smile on my face, I still feel like a total jackass for not using $2 worth of plastigage and checking that. Had I of taken that extra four minutes, I would have quickly found that.

I do blame the machine shop some, but, ultimately, the responsibility of double checking falls on me(you). The only way I learn my lesson(s) is when it cost me a combination of money, time, and/or grief-- this simple error caused plenty of all three.

I will now confidentally reassemble this motor (once back from that same machine shop) and finally start enjoying this car/motor!

The moral of this story: spend $2 on plastigage and double check those clearances!!!

Have a good day!
Michael
 

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.010" under bearings on a .020" under crank...tsk-tsk...sorry to hear it...with all the people dismissing plastigage, this is a very good example of what it can do for an end user.

I don't recommend Plastigage exclusively, but this is what Plasitgage is good for. I mean, mic your parts for proper clearancing, sure, but sometimes the bearings are mispackaged and we miss this, and that's where Plastigage can reveal the discrepancy in the blink of an eye.

Some years ago, I was employed as a Service Tech for a major motor vehicle manufacturer. When we built motors, the bearings were color coded. WELL, someone at the bearing factory was color coding the bearings the wrong ID colors, and so they were getting boxed in the wrong boxes/part numbers. I found the discrepancey during a motor rebuild...had to look at the bearing shell's box part number and color code of the bearing about 5 times, then squash another piece of plasitage to confirm my findings. The resulting nationwide recall (pulling all the bearings off the inventory at all dealerships) was done quietly...public was never told.

Don't know if you were handed the incorrect bearings or if they were mispackaged, but either way plastigage would have revealed the discrepancy.

Paul
 

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Good info..

Good info, Michael. Thanks for sharing. I sold parts for a while, and I know how that stuff can happen. I hope you get it back together with no more hassles.
 

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bearing clearances

i'm not knocking on how anybody builds motors .but i have been asked plenty of times why my motors cost so much more than so and so's motors ,and i have to tell them its because of check and double check .the blueprint part of a race motor or hot street motor is vital for its longevity .mic and dial bore gauge all clearances.degree all cams ,check piston to valve clearance and rocker geometry .and make sure all ports and gaskets lne up .those are just some of the proceedures that make the difference between a so so motor and a one that will be ther when its time to call on it and it will satify you .step up and spend the bucks and get it blueprinted . now off my soap box . ron
 

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I've always said, Plastigage may not be dead-on accurate BUT it always reveals installation problems with bearings and machine work. Don't forget that plastigage is supposed to be used dry (without oil during mock-up/checking). Use the proper size (four sizes available) and use fresh Plastigage (it has a shelf life). I think you'll be fine this time (but check everything).
 
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