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Discussion Starter #1
Ok!

I am sure this has been asked in the past, but here goes!

What clearances should I be looking for on my crank and rods?
I am using a stock crank and stock rods.

Using a plastigauge, what measurement should I be after?

This is the first time I have attemted something this in depth with a motor.:WTF

I must be nuts to have started this!

Just got everything back from the machine shop and I am ready for assembly.

Thanks!
 

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for your first time id suggest getting an OEM manual or a book on rebuilding a 350. You'll need it for all the torque specs and other build parameters.
 

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Discussion Starter #3
I have the haynes book for the car. I am just looking for a little advice using the plastigauge. I have never used one before.

The book has the torque specs, etc. I was just seeing if anybody had some tips on where I should be at.
 

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Im to lazy to type but there are many articles on this.


How Plastigauge works with engine bearings

or

HOW TO USE PLASTIGAGE


When checking connecting rod bearings, turn the crankshaft so that the journal to be checked is about 30° from bottom dead center.



Remove the bearing cap and wipe the oil from the bearing insert and crankshaft journal.

Tear off a piece of Plastigage as long as the full bearing width. (Tear through both the envelope and plastic thread at the same time.) Lay the piece of Plastigage across the full width of the lower bearing shell about 1/4" off center.

Install and tighten the bearing cap to the proper torque specifications. Do not rotate the crankshaft while making thischeck.

Remove the bearing cap. The flattened Plastigage will adhere to either the bearing shell or the crankshaft.

Compare the width of the flattened Plastigage at the WIDEST point with the graduations on the piece of envelope torn off in Step 2. The number within the graduations, which matches the flattened Plastigage width, indicates the total bearing clearance in thousandths of an inch or in millimeters. If the width of the flattened Plastigage does not exactly match one of the envelope graduations, interpolation can be used to determine the fraction of a thousandth in the same manner as when using micrometers.


TAPER


When one end of the flattened Plastigage is wider than the other, a difference in clearance is indicated. This difference is the amount of taper in the journal. Measure both ends of the flattened Plastigage. The difference between the wide and narrow readings is the approximate amount of taper.


OUT OF ROUNDNESS

This can be approximately determined as follows:

1 Place the connecting rod at bottom dead center and measure the bearing clearance with Plastigage.

2. Rotate the crankshaft approximately 100- from bottom dead center and again check the bearing clearance with Plastigage.


The difference between the bearing clearances measured in Steps 1 and 2 approximate out-of-roundness.

Upon completion of a clearance check, the flattened Plastigage can be scratched from the bearing or journal with a thumb nail. However, no harm is done if removal is over-looked. Plastigage is oil soluble and will disappear within a few revolutions of the crankshaft.
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How to use plastigage to measure clearances

1
If you are going to measure a crankshaft, assemble the engine together with the crankshaft installed with the new bearing inserts in the block and main caps. Make sure all the caps are numbered, in order and installed properly with the arrows pointing forward. All fasteners/bolts will need to be torqued to specification.
2

Loosen the bolts of the bearing cap that you want to check clearance on. Remove the bolts and the cap. Wipe assembly oil off of the surface of the crankshaft where you want to check for clearance, use a clean lint free paper towel or cloth.
3

Tear off a piece of plastigage. You will need to open the paper to remove the plastigage, place the plastigage across the surface of crankshaft. Try to position the plastigage in the center of the journal surface. Install the bearing cap and torque bolts to specification, remove the bolts and the bearing cap. You will see the crushed plastigage on the journal.
4

Using the paper that came with the plastigage, use the scale on the side of the wrapper to measure the crushed plastigage. Compare your measurement to the clearance specification, if you are within range then you are ok to assemble. If the measurement falls between two sizes then you can estimate what the size in between is.


Read more: How to use plastigage to measure clearances | eHow.com http://www.ehow.com/how_2142943_use-plastigage-measure-clearances.html#ixzz18DNt5ybM
 

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Discussion Starter #5
OK.

All my main bearings are measuring at .002 on the plastigauge. From what the book says this is fine. I dont see any differences in the measurements. all the lines of plasti are very straight. So it looks like I will set these in place.

Unless anyone thinks otherwise?
 

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Discussion Starter #8
Amtech casting on 22nd street in tampa.

Cool!!!:D

I can't wait to finally drive my baby again!! I just want to feel good about getting in it and blasting around. It has been seven years since she was road worthy. She is my first vette. hopefully not the last!!

Can't wait to take my little boy for a ride in it. He is out their every time I am in the garage asking when we can go for a ride.

soon buddy! that's all I can tell him.
 

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Discussion Starter #9
Well after a nice long day at work I managed to assemble the crank and pistons! All the clearances seem to check out fine. :thumbsup:

Thanks
 
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