12/28/2023 0 Comments Honda civic piston rods marked 2 and 3![]() Before beginning the assembly, since we wanted to be cautious that we had removed all of the WPC media from the block, we sent the block out to be ultrasonically cleaned and then gave it a good scrub down using a plastic bristled brush and liquid Tide. With all of the hardware now sourced for our bottom end, we were almost ready to begin its assembly. To compensate, a slightly thicker wall wrist pin was used in tandem with the higher strength 9310 material. With a decrease in wrist pin diameter, comes a slight decrease in strength and stiffness. Why? A 20 MM pin is what the QR25DE uses from the factory. Instead of the factory 21 MM diameter pin though, a 20 MM sized pin was selected. An accumulator groove is designed to increase the area under the first compression ring and reduce the chances of pressure build up and ring flutter at high RPM.Ī 9310 alloy steel wrist pin is used to join the K1 Technologies connecting rod with the forged JE piston. To round out the piston's features, JE Pistons coated the piston's skirts and machined an accumulator groove into the second ring land. The WPC give longer ring, bore and piston life as the treated surface retains lubrication better and is inherently harder and slippery due to the process characteristics.Īt the same time, we had JE pistons increase the compression ratio a point and a half to 11.5:1, which should still be street-able even with California's lousy 91 octane gas. We also WPC treated the bores after machining for less ring and skirt friction and longer life. Hey, it's not much but we'll take what we can get since this motor will be sucking instead of getting blown. One of the side benefits of this increase in bore was a small increase in displacement of 22 cubic centimeters. Since our B18C1 had seen over 200,000 miles of service, we decided to bore and hone our block to 81.5 mm before putting Humpty Dumpty back together again. 989″ compression height, we turned to JE Pistons to design and manufacture a set of forged pistons for our long rod B18C1. Having figured out conceptually how we were going to run our short. Absence of a rail support would cause the oil ring assembly to essentially unwind itself and spiral through the opening in the ring groove. Appropriately named, a rail support does just that, supports the oil ring rail and assembly across the opening in the ring groove caused by the pin bore. In cases where the pin bore crosses into the plain of the oil ring groove, an additional steel rail called a “rail support” is installed underneath the oil ring assembly. 989″ compression height we didn't have to go to any of those extremes however, the pin bore was run into the oil ring groove and it was necessary for us to run a rail support.Ī detent as well as tension, locks the rail support in place and keeps it from rotating out of the opening. Actually, it's about as short as one can go without ditching a compression ring, using pin buttons, or having an unacceptably small wrist pin diameter. 989″ is pretty short for an automotive street application. 989″ Compression DistanceĪ compression distance of. In our case, the new compression distance for our long rod pistons worked out as follows: (Block Height) – (Rod Length) – (½ Stroke) – (Deck Clearance) = Compression Distance To figure out the new necessary compression distance is simple and can be calculated using the formula below. ![]() Compression distance, also known as pin height, is the distance from the center of the piston's pin bore to its deck. Without a piston that is shorter in compression distance, none of this long rod business would actually work. With the crank and rod situation figured out, there remained one missing link to make this exogamic marriage of Honda and Nissan components complete. ![]()
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