A: Any bolt can be torqued. The question is: will using the torque method of tightening a bolt give you good, repeatable results? This is important because at top dead center of the exhaust stroke, the piston wants to continue right up through the cylinder head and the crankshaft wants to pull the piston back down the cylinder walls. At high RPM this load can exceed 18,000 pounds of pull on the cap. It is the job of the bolt(s) to provide enough clamping force to keep the cap from separating from the tower of the rod. The problem is a torque wrench only measures friction not clamp load and every time you tighten the bolts you change the mating surfaces of the threads and where the head of the bolt contacts the rod. This changes the amount of friction that must be overcome to correctly tighten the bolt. What this means is if you tighten the bolts to the same torque level, you will have a different clamp load on the bolts each time. Because of the large potential variations in the actual clamp loads achieved by using torque, we strongly recommend against using torque.

Return to Top

A: We didn't invent this. It has been used by automobile and diesel manufacturers and in the aerospace industry for many years because it is much more accurate than using torque to tighten bolts. Torque and Angle uses the pitch of the threads as a good, repeatable reference for properly tightening the bolts. For example, if the bolt has a 7/16" 20 threads per inch pitch, then one full (360 degree) turn of the bolt will move the bolt exactly .050" (fifty thousandths of an inch), or 36 degrees of turn will move the bolt exactly .005" (5 thousandths of an inch). We have a specification for Torque and Angle for all of our bolts, no matter their size (5/16", 3/8", 7/16" etc.) and our specs are all derived from the pitch of the specific thread on each size of bolt.

Return to Top

A: Don't confuse torque and angle with torque to yield. Torque to yield stretches the fastener past the point of where it will not return to its original length. This weakens the bolt and makes it unusable for repeated tightening. When you use the torque and angle method according to our directions, you will stretch the bolts to 75% of yield. This allows the bolts to be used repeatedly without fear of weakening them.

Return to Top

A: The correct answer to this question is: it depends. It depends upon the fatigue loads the bolts will see in use. The higher the loads, the shorter the fatigue life of the fastener. Our staff can assist you in selecting the proper bolts for your application and in turn, give you a reasonable estimation of the fatigue life of the bolts in your application. Bolts are nothing more than very stiff springs and as long as you do not stretch them past the yield point, they will return to their original length and can be tightened repeatedly. Some manufacturers are still supplying a torque number to tighten their bolts. As the bolts are reused, you actually change the surface finish of the threads and the underside of the bolts and by tightening to the same torque level, you will not have the same clamp load. In some instances, especially when using improper lubrication, the bolts can be tightened too tight and the bolts will have "yielded", all while using the torque method alone. Other manufacturer's "fix" is to sell you more bolts. It is our goal to help you understand the function of the bolt so you can use the bolts over and over instead of replacing your bolts before you really need to.

Return to Top

A: We highly recommend that you keep a log of the un-tightened length of your bolts (keep in mind all bolts are a different length). Whenever you remove your bolts from the engine and they do not return to the original length, they should be replaced.

Return to Top

A: Connecting rods do not break due to horsepower, they fail due to tension loads. Heavy pistons, long stroke cranks and high RPM will actually pull a connecting rod in two. The goal is to select a rod that will handle the tension loads produced by your engine combination. Please call our toll free tech line at 800-253-8108 for assistance with your connecting rod selection.

Return to Top

A: A steel forging is stronger than a steel billet only if both parts are not heat treated or if they are not heat treated correctly. When a part is heat treated correctly, it is heated to a temperature that changes the grain structure and removes the grain flow that is present in a forging. Proper heat treatment will change the steel to a fine grain structure that is stronger than the structure that is found in a forging.

Return to Top

A: We have proven through engineering and the use of FEA (finite element analysis) that our Parabolic Beam (TM) is a superior design and carries loads produced by racing engines better than even the most popular 'H' beam designs.

Return to Top

A: Oliver is more expensive because it is a better product and costs more to produce. There are always places where you can save a little money in a racing engine, but connecting rods are a very highly stressed item and if you break one, lots of other parts will get damaged. In just about every case, the cost to repair your engine will far exceed the amount of money you save on cheap rods. Remember you can buy cheaper, but you cannot buy better.

Return to Top