DIY: Installing a Piston and Rod Assembly

**Kirk** · 11-14-2007, 03:02 PM

Tools.
Ring expander
Ring compressor
plastic mallet
block of wood or the handle of above mentioned plastic mallet
feeler gauges
assembly oil or light engine oil
You should have all the other tools needed.

1: Insert a new piston ring into the cylinder. Use the head of the piston to position the ring so that is is square with the cylinder wall, next use a feeler guage to check the end gap. Compare the endgap specs from the tsrm with the measured gap and correct as needed. Normally, the gaps of the piston rings are staggered to prevent them from being in line with each other, the rings will be installed easily with a ring expander.

2:Before attempting to install the iston and rod assembly into the cylinder bore, makre sure you place rubber or aluminum protectors/boots over the threaded section of the rod bolts. This will help prevent bore and crankpin damage.

3:Lightly coat the piston, rings, rod bearings, cylinder wall, and crankpin with an approved assembly lubricant or a light engine oil. Some people submerge the piston into a large can of clean engine oild before its installed which is also acceptable.

4:Stagger the ring end gaps and compress the rings with a ring compressor. This tool is expanded to fit around the piston rings, then tightened to compress the rings. When the rings are fully compressed, the tool will not compress any further. The piston should fit snugly, but not tightly.

5: Rotate the crank untill the crankpin is at its lowest level (bdc). Then place the piston/rod assembly into the cylinder bore until the ring compressor contacts the cylinder block deck. Make sure that the piston reference mark is in correct relation to the front of the engine. Also, when installing the assembly make sure that the rod threads do not touch or damage the crankpin!

6: Lightly tap on the head of the piston with a mallet handle or block of wood untill the piston enters the cylinder bore. MAKE SURE WHATEVER YOU USE IS CLEAN! Push the piston down the bore while makeing sure the connecting rod fits into place on the crankpin. Remove the protective covering from the rod bolts now.

7: Position he matching rod cap and finger tighten the nuts. Make sure the connectin rod blade and cap markings are on the same side, now gently tap each cap with a plastic mallet as it is being installed to properly position and seat it. Torque the rod nuts to the specs in the tsrm.

8: Repeat for each assembly.