Engine Build Pre-Assembly (piston ring gaps, piston to wall clearance)

When I got my engine block I purchased a set of piston rings to go with it.  They were the file to fit type, which they make larger so they can be filed to a specific gap.   Which in this case I was reccomended by Keith Black (manufacturer of my pistons) 0.028" for the top ring and 0.018" for the 2nd ring.  I had done the filing years ago when I originally got everything.  This week I got out all the rings that were individually packaged per cylinder and I checked all the gaps to make sure I gapped them right years ago.

 

Below is a picture of a tool used to insert the piston rings evenly down into the cylinder squarly so the gap can be checked.

 

Here is a picture of the piston ring into the cylinder.  The gap can be seen at the top if you look closely.

A feeler gauge is then used to check the gaps.  This is then done for the 2nd ring also and for all 8 cylinders.  I guess I did a good job a few years ago when gapping these rings because they all were good.  I replaced them into their labeled bags and set them aside (I won't need them until final assembly).

Next,  I had to measure the pistons.  Every piston manufacturer has a specific spot on their pistons where they are measured.   I assume this is because it is at this spot where the piston is the largest.  I went onto the Keith Black website and found the installation instructions for my pistons.  In these instuctions it tells me where to measure them.

Here is the link for the installation instruction sheet for my pistons for an example

https://www.uempistons.com/installation_instructions/kb_installation.pdf

In the picture below I am measuring the #4 piston with my 4"-5" micrometer.  I measured all 8 pistons this way.  All of the pistons measured within .0005" of each other.

I then got my dial bore gauge out again.  I set up the dial bore gauge zero to each piston measurement.  I then inserted the bore gauge into the cylinder and took the readings at the top middle and bottom of the cylinder.  Because the zero on the bore gauge was set to the piston measurement the gauge then read the piston to wall clearance.

The picture below is how I set the bore gauge to zero using my micrometer set to each specific piston size.  It's hard to take a picture of this, but I tried my best.

I checked each cylinder horizontally and vertically to double check the machining work and make sure the cylinders aren't out of round.

The picture below is showing an example of one of the cylinder piston to wall clearances I got.  Each line is 0.0005".  So this is reading .0020" clearance.

 

 

All the piston to wall clearances checked out ok from .0020" to .0025".   I once again looked at the piston installation sheet that I printed off from the KB website.  These clearances were exactly what they suggested for a street performance engine.

 

Here is my handy white board again with all my measurements recorded.

 

Time Lapse Video

I recently got myself a new phone app that allows me to make time lapse videos.  I was playing around with it and made one of me putting a piston together and I thought I would share it.  Here is the youtube link to it. 

https://www.youtube.com/watch?v=iy7OP-fL8Ao


I really like this app.  It's called Osnap.   I'm sure I will be making some more of these videos.

Engine Build Pre-Assembly (piston assembly)

 

 

Next job to do was assemble all the pistons with their connecting rods.  This job wasn't overly difficult, just tedious.  The pistons and connecting rods that I have are full-floating pin type, which means that the piston wrist pins are held in the rods and are not pressed in.  The wrist pin in my case is held in with spiral locks.

 

The picture below shows everything I used to assemble the #2 piston.



 

Each connecting rod has a flat side (below left picture), and a chamfered side (below right picture).  Before assembling each rod and piston I needed to make sure I had it in the right set up.  The chamfered side rests up against the crankshaft and the flat side butts up against the other connecting rod that it shares the journal with.  The Piston also needs to be in it's right position too.  In my case the intake valve relief needed to be set up as shown in the picture below.  I labeled the piston so I got it right.  The connecting rods NEED to be checked and double checked that they are correct, which I got one of them wrong (more on that later).

Here is a picture of the spiral locks.  These are a pain, but once I did a few they got easier.  Each one is stretched out to about 3/4".

I have a small pick set with tools that resemble something a dentist would have.  I found that these worked well for this job.  The first spiral lock is worked into the groove in the piston and slowly spiralled into the groove using my small pick.  Get the band aids ready......I cut my fingers several times.

The wrist pin is lubed up with some assembly lube that was supplied with my pistons.  I also put some in the connecting rod bore.

The wrist pin is slide in and then the spiral lock is installed on the other side.

Now, more on my mistake.  I don't mind admitting when I make a mistake.  Maybe someone reading this will learn from my mistake.  When I was putting the #2 piston and rod together, I didn't double check that I had the connecting rod in the right position.  I installed the piston and rod together and had both spiral locks installed.  I grabbed the assembled piston, and took it over to the block to check it.......it was wrong.  I had the rod in backwards with the flat side facing the crankshaft and the chamfered side facing towards where the #1 rod would be.  After I was done swearing, I started trying to work the spiral lock back out of the piston.  They are WAY harder to remove then install.  After about an hour I had it out.  I used two tiny flat head screwdrivers.  One to lift the end of the lock up and then the other to pry it out.  After I had the rod flipped over in the right position I installed a new lock back into the piston.  I searched the Internet about whether I should reuse the spiral lock that I had just removed and couldn't find a solid answer.  For the cost of a new lock ($0.97) I just put a new one in to be safe.

Here is a couple pictures of the finished products.

Engine Build Pre-Assembly (crank endplay, connecting rod oil clearances)

The next measurement for me to take is the crankshaft endplay, this is the amount of forward and rearward movement of the crankshaft.   After I had finished measuring all the main bore oil clearances the main caps were once again removed.  The bearings were lubricated.  The crankshaft was once again installed and the caps were retorqued down in place.  For this measurement I once again used my magnetic base and dial indicator and set it up with the dial on the front of the crankshaft.  Using a large screwdriver I pryed the crankshaft as far as I could to the back of the block.  The dial indicator was then zeroed.  I used the large screwdriver to pry the crankshaft as far forward as it would go.  I then took the reading off the dial indicator.  The endplay on this engine is .005"  which is right on spec.

After I checked the endplay I moved on to the connecting rods.  I checked the oil clearance for all 8 connecting rods using the bore gauge method that I used for checking the oil clearances in the block mains. 

The bolts were removed from each rod and the rod was seperated.  Some of them were pretty stuck, so I used a rubber mallet to tap them loose.

Here is a couple pictures showing the new Clevite bearings that are used in the connecting rods.  Because my crankshaft had been ground down .010" I had to get bearings that were .010" oversized (same goes for the main journal bearings).

I purchased a new set of connecting rod bolts from ARP for all 8 rods.  I decided to do this because my connecting rods were bought used.  Even though they look in excellent shape, I just don't know what those bolts have been through (abused, dropped, over-torqued etc.).  So for the added insurance I got a new set and swapped them in.

Once again, I coated each bolt with ARP ultra torque lube.

The bearings were installed in the rods and the caps.  The caps were reinstalled with the new bolts.

The bolts were then torqued down to 63 ft/lbs, which is the torque recommended by ARP.

It was difficult to take a picture of this.  This is how I zeroed the bore gauge.  I would set my micrometer to a given measurement, in this case I set it to 2.190" (the measured rod journals on the crankshaft).  I would then put the bore gauge in the micrometer and then set the dial to zero.

The bore gauge was then put into the  connecting rod.  The dial will then be reading the difference between the crankshaft journals and the connecting rod bore (oil clearance).

 

 

The connecting rod oil clearances came in right on spec from 0.0025"- 0.0026"

 

Engine Build Pre-Assembly (crank straightness, crank measurements and main bearing oil clearances)

 

Before I put the engine together for the final assembly there are some critical measurements and clearance checks that need to be completed in any motor to ensure that this engine will have a long life.  In the next few entries I will be going through these checks and I will try and explain the best I can.

 

Here is the Crankshaft.  I cleaned it up with some brake cleaner.

 

The first thing that I checked is the straightness of the crankshaft.  To do this I installed the #1 and #5 main journal bearings with some lube, I then set the crankshaft into the block carefully (it's heavy!).  I then install the main caps on #1 and #5 and torqued them to spec.

To check the straightness of the crankshaft, I used my magnetic base with a dial indicator setup on the #3 journal.  I zeroed the dial and then rotated the crankshaft a few times and see if the dial reads anything.  I then moved the dial indicator to the front snout of the crankshaft did the same thing.  I then took the #5 main cap off and put the dial indicator on the rear main seal surface.  everything checked out perfect, which means the crankshaft is perfectly straight. 

Here is a picture of the main caps with their bearing halfs installed. 

I then installed the rest of the main bearings in the block.  I then lubed the bearings up, set the crank back into the block.  I installed all the main caps and torqued them to spec and then spun the crank by hand making sure it spun with ease.

Every time I torqued any bolts down I coated the threads and washer faces with ARP lube.  This is used provide accurate torque readings each time.

The main caps were then taken off and the crank was then removed again.  The lube on all the bearing surfaces was then all wiped clean and the main caps are reinstalled without the crankshaft and torqued to spec again.

I then took my 2"-3" micrometer and measured every journal on the crankshaft and recorded the readings I got.  These readings will be used later. 

The next check I did required using a dial bore gauge.  I had never used a dial bore gauge before, so it definitely took me a little while to get the hang of this tool.  I'm not going to go into much detail on how to use this tool, but if you are wondering how to use it I found a lot of helpful youtube videos on how to use one.  I was using it to check oil clearances.  so what I did was take each journal measurement from the crankshaft and set zero on the dial bore gauge to that measurement.  Then when I put the dial bore gauge into each main bore in the block and took the reading it read the difference between the crank and the block, giving me my oil clearances

I then repeated this for each main bore and recorded each reading

All the main oil clearances on #1-4 bores came in between .0025" - .0028" and the #5 bore came in at .0032".  It is normal for the #5 main oil clearance to run a little looser.  I would like to note that all these measurements I did were double and triple checked each time.  I am happy with all the measurements I got so far and are right on spec for my engine.

Just as a added insurance, I decided to check all the main oil clearances with Plastigauge.  Plastigauge is a little strip of plastic that is put on each crank journal, then the caps are torqued down on top of it.  When the caps are torqued down it squishes the plastic.  The caps are then removed and the squished plastic is then compared to a clearance chart, giving a clearance measurement.  This method is less accurate but still works.

The thin strip of plasticgauge is hard to see in the picture below unless you look closely

In the picture below, I am comparing the squished plastigauge to the comparison chart found on the plastigauge package.  All my plastigauge readings came in at around .002" give or take a bit.  So as this is a less accurate method of measuring clearances I am happy with those results.

In the picture below it shows my white board that I mounted to my garage wall.  I bought this from walmart and find it to be a great investment, it comes in very handy for recording all my results as I go.