Hastings 2M139040 Piston Ring Set

Brand	Hastings
Model	2M139040
Size	.040

Piston Rings

4.040 in Bore

5/64 x 5/64 x 3/16 in Thick

8-CYL RING SETHastings Moly .040 over piston rings.Applications.040 over327 and 350to 1985 small block Chevyengines..040 over289 302and 351W Ford engines with the following ring grooves. Bore Size Ring Width 4.030 5/64 5/64 3/16 Also available in Std .030 .060Quantity - 1 SetPart # 2M139-40Moly ring Set for common 350 chevy 4.040 bore, 302 Ford 4.040Bore, 351w, 351m, 400 Ford 4.040 bore... please check ring groove sizes below.ThisHastings ring set hasMoly coated Top Rings, and featureHastings Flex-Vent oil control rings to eliminate blow-by, and cast-iron second groove rings with a reverse-twist taper face for reduced friction. Top Groove 2nd Groove 3rd Groove 5/64 5/64 3/16 Ring gaps are often a confusing and misunderstood part of a rering job. There re MINIMUM and MAXIMUM ring gap specifications which must be observed for the best performance of a new ring set.Minimum gap tolerances must be observed in order to prevent the ring ends from butting together as the ring expands when the engine approaches operating temperature. Hastings recommends a MINIMUM of .0035 gap per inch of cylinder diameter. Example: 4 (bore) x .0035 = .0 14 minimum gap.Maximum ring gap is an important part of ring performance in that too much gap results in lost compression, power loss and ultimately poor oil control. The following chart indicates the specifications for compression ring gap as outlined by the SAE (Society of Automotive Engineers) as standards for the automotive piston ring manufacturers.An important fact to remember is that the manufacturers rigidly adhere to these tolerances and that the ring gaps are inspected in gauges accurate to .0001 at the cylinder diameter the ring is manufactured for. Any increase in the diameter of the cylinder is being used in, over the designated size, results in an increase of approximately .003 in ring gap for each .001 increase in cylinder diameter.In order to