Thread: 355 build HP and Torque?

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The piston ring grinder arrived today, so I was able to get back to working on the shortblock. This little tool was a lifesaver. I can't imagine filing the ring ends manually with a file, as the top rings measured close to .015 and needed to be filed to .026 per KB's chart for the pistons I'm using. The instructions with the grinder said to be very careful not to take off too much, so the first couple rings took a long time as I filed, deburred, and checked multiple times before I got the full gap. After that, I got a better feel for how much I was grinding, and the last few rings were done with only a couple grinds each with the tool.


The 2nd compression rings all measured close to .018 or greater which is right where they should be so I left them as is and didn't need to grind them. I methodically checked each ring gap in the bore it would be installed and then assembled them on their perspective pistons. It took some time to figure out an easy way to put the rings on the pistons, but by the time I was half way through, I had figured out a system and got pretty good at quickly putting them on.


I clocked the rings first with the oil ring components evenly spaced around the circle or about 120 degrees between parts. The compression rings were clocked 180 degress from each other and 45 degrees from the wrist pin. I heard that they all tend to rotate and shift when the engine was running, but that I should avoid having them line up with each other during the initial install. With the bearing dry fitted in place on the rod and a couple pieces of fuel hose over the threads to protect the cylinder walls and bearing journal, a lot of oil on the cylinder and piston, and the ring compressor in place, I was ready to place the new piston in the bore.


With the compressor as tight as I could reasonably get it and square with the block, the pistons were tapped into the bores with the wooden handle of my hammer. I noticed on a few of the installs, the rod bearing would come lose from the rod and either fall off or rotate a little and needed to be reinstalled or straightened before I could fully seat it against the journal.




I checked the first two rod bearings with the plastigage and they both showed a little less then .002 clearance. After that I decided not to check every rod as it seemed like a lot of extra steps to first assemble the bearing dry, do the plastigage thing and then to back off, lube up the journals and reassemble and retorque the caps. I hope I don't regret this in the future, but it does remind me of how impatient I get when some of these details are taking so long and I just want to hurry and move on to the next step. By this point in my evening, it was already getting late, I was tired, and I had spend a lot more time on the ring gapping then I had imagined.


By the end of the evening, most of the pistons were installed and the bearing caps torqued to 35 ft/lbs in a 3 stage torquing. I did notice at this point that the bottom end of the block was getting quite heavy and my homemade engine stand was requiring a lot more manual effort to rotate the block upside down. I think in the future it would be nice to have one of those fancy ones with the rotating cranks to help save my back. Actually I'm thinking I could probably modify my homemade one to bring the engine higher so the center of gravity is closer to the pivot point at this stage in the build. My theory, is that after the pan is installed and the heads and manifolds are added, giving more weight to the top, that the need to rotate the assembly upside down should not be necessary.