Valve Spring Tests

First order of head jobs was to find the correct valve springs. For this I had borrowed two test springs and solid lifters so I could measure the installation and open heights. As I would have to bolt the head on the block, I also decided to measure the valve-to-piston clearance. So, two valves went in the head.

For the piston clearance I placed some blu tack in the valve reliefs.

And I was ready to bolt the head to the block. I made sure to follow the correct order for torquing the bolts and then installed the lifters, push rods and original rocker arms. Before adjusting the lash, I rotated the crank until both valves were closed and then tightened the nut until the push rod just started to feel sticky. Time for measurements. Results were:

-	Intake	Exhaust
Installation height	1.80 inches	1.75 inches
Open height	1.33 inches	1.28 inches
Lift	0.47 inches	0.47 inches

Now I was able to find correct valve springs. Not that surprisingly after a phone call to US-Parts, we came to the conclusion that I should buy what Comp Cams suggests for my cam: Comp 942-16. They had the correct pressure and height so I went and bought a set. Their required installation height was 1.7 inches though so I would have to measure every valve and add shims to get it correct.

Finally I removed the head and checked the blu tack.

The valves had hardly even touched it. After cutting both in half, I measured the clearance to be 0.25 inches. No problems there.

Engine Assembly: Installing The Pistons

Next task on the assembly list was installing the pistons. First they needed to be ringed though. The ring gaps had been inspected so I got on with it. Oil ring assembly was first. They were made from spring steel so installation tools were not needed. I just spread the expansion ring and pushed it in the bottom groove. The side rails followed. I was not worried about the gap positions for now. I'll set them right before installing the pistons.

The compression rings are a bit harder so I bought pliers for them. They were only a few euros and made installing the rings really easy. I just had to make sure the moly faced ring was installed to the top groove and that they were installed the correct side up. This was indicated by a dot on both rings.

Then it was time to insert the pistons to their cylinders. Before the final install, I wanted to check the bearing clearance though. I did that only for the first piston as testing all of them would have been somewhat pointless. First the bearings.

Then pieces of rubber tubing over the bolts to protect the bores.

And installation. I had a cheap ring compressor that I screwed around the piston. I sprayed WD-40 on everything and then tapped the piston in. The compressor unfortunately got stuck a bit and broke as I pulled it out. So much for cheap tools. At least I got the clearance measured with Plastigage again.

As with the main bearings, the result was about 0.002 inches. Acceptable range should be 0.002 - 0.003 inches so I was fine.

I did some reading and apparently the best tool for installing pistons is a tapered aluminium ring that is precision tooled for a single bore size. So I went an bought one by Moroso.

You can only use it for 4.030 inch bore size but I don't think I'll be building another engine any time soon. After pulling the first piston out again, I prepared it and the crankshaft for final install. This meant spreading some assembly lube on the journals and bearings...

...then turning the correct journal to bottom dead center (BDC), oiling the bore, locating the ring gaps and using the tool to tap the piston in. For ring gap positions I used the ones instructed in Millers book.

I have to say that the installation ring was an excellent tool! I did not have a single problem with any of the pistons. They just smoothly slipped in the cylinders. I pushed the piston in until the bearing contacted the journal.

Final step before placing the cap on the rod was checking that the locating tab on all the bearing faced towards the center of the block.

This meant that the rod had been installed correctly on the piston. Everything was OK in that front so I torqued the cap nuts to 24 ft-lbs. And after a few hours of work, all the pistons were in!

Turning the crank was naturally much harder now but everything still moved smoothly so this job was done!

Engine Assembly: Piston Ring Gaps

After the first few visual checks it was time to get serious. The Sealed Power piston rings that I had bought were pre gapped but I was following "How to Rebuild Small-Block Ford Engines" book by Tom Monroe and it instructed to check everything. So I got busy.

I pushed each ring in its respective cylinder and then squared it with one of the old pistons. I removed the top ring from it and then just pushed the new ring in with it.

Then it was time to check the gap with feeler gauges. After going through every ring, they all seemed to have 0,40 mm (0.0157 inch) gap. I did some reading and it was maybe a little tight. Also, I found more modern suggestions that the bottom ring gap should be a bit larger so any pressure that goes through the top ring is not trapped between the rings.

I clamped a fine toothed file to my table and went through the rings once more. I filed a tiny amount at a time and measured again many times until all top rings had 0,45 mm (0.0177 inch) gaps and bottom rings 0,50 mm (0.0197 inch). Finally I removed the sharp edges from the filed end with 600 grit sandpaper.

I will install the rings to the pistons later when it's time to put them in the cylinders.

Piston Weights

As I had to install new pistons, I was a bit worried that it would ruin the balance of the moving parts. So, before taking the old pistons to the machinist, I weighted them. After getting them back, I did a comparison. These weights contain the piston, pin, rings and connecting rods.

Piston	1:	2:	3:	4:	5:	6:	7:	8:
Old	1374 g	1370 g	1379 g	1376 g	1377 g	1370 g	1374 g	1373 g
New	1377 g	1375 g	1381 g	1378 g	1378 g	1372 g	1378 g	1375 g
Difference	3 g	5 g	2 g	2 g	1 g	2 g	4 g	2 g

Wow, only a few gram difference in each piston. I think I'll call a professional and ask if that makes any difference. Most likely not as, according what I've read, they didn't even balance the moving parts in the factory and my engine would not see high RPMs.

And just in case someone is interested, I also weighted just the new Sealed Power hypereutectic pistons and pins. They were between 750 and 753 grams. And for the new piston rings:

1st pressure ring	2nd pressure ring	Oil ring
17 g	20 g	22 g

Block Party

It took a bit longer than expected but I got the block back from the machinist yesterday. I drove to Koneistamo Aaltonen in Mäntsälä and we went through the work that had been done. They had bored and honed the cylinders, cleaned the block, replaced the cam bearings, checked the head surfaces for straightness and checked the crank line for straightness. In addition to the work with the block, they inspected the connecting rods and replaced the pistons.

I also brought my new Comp Cams XE250H camshaft with me so they could check that it fit correctly. The cam was installed in the block but rotating it was harder than expected. The cam was inspected and found to be a few hundredths twisted. They straightened it and got it turning properly.

After getting all the parts to the garage, I checked the basic stuff. The block itself looked fine and just needed some paint.

The piston rings that I had bought were molybdenum faced and the cylinders had been honed appropriately. With moly rings the honing stone must be much finer as they do not need the coarse walls to hold the oil. Everything was good in that front.

Then I made sure that all the cam bearings had been installed correctly. Their surface was nice and you could see their oil hole through the main bearing channel.

Next came the pistons. I measured their weight and visually inspected all of them. I did notice that the wrist pin clips had not been installed. I'll have to make sure they are needed and then squeeze them in.

My crank had already been machined earlier. All the bearing surfaces seemed perfect. I'll just have to measure the clearances later.

After these basic checks I can start planning the actual assembly.