engine compression

I just bought a used 5.3L LS engine out of the junkyard and after we got the engine back to the shop and mounted it on an engine stand, we decided to do a leakdown test. We checked all eight cylinders and the average was close to 40 percent. We removed the oil filler cap

Got questions? We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we discuss the basics of compression and how it relates to your fuel octane. T.C. • Dayton, TX Q: I have a 1993 Chevy Silverado Z71 and according to the repair manual, my small block’s compression is 8.2:1. What

Got questions? We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we help a reader overhaul his Rat motor for street/strip performance. G.T. • Keaau, HI Q: I have 1973 454 big block Chevy. It has 8.5:1 compression, stock oval port cylinder heads, a Crane PowerMax camshaft, an Edelbrock Performer