Wrist-Pin Locks and Types Wrist pin locks are spring-type fasteners designed to provide an interference fit in a groove machined at the edge of each pin boss on the underside of the piston. We had the 120R heads worked over by Mackie, whose porting skills and finishing work are second to none. The wrist pin is held in check and kept from scratching the cylinder by a spring-loaded lock on each side that secures the pin between the pin bosses. The only tools I found were for 22mm and under, the Fiat circlip is 24mm. After trying various methods and home made tools, I had given up and went online to buy a tool. I took them all and came up with what turned out to be a straightforward, relatively easy installation process. After we got some specs from TR and passed the info along to Darkhorse and Dave Mackie, the two were able to set up our heads and the crank accordingly and get the bottom end on its way back to the shop. Thanks for all the tips on the circlip installation.
The kit is a bolt-on and requires no case boring.
#Wrist pin g clip installation upgrade
TR informed me that he has developed a 124-inch upgrade kit for the 120R crate motor using Nikasil cylinder technology as well as a new piston ring design. To do this, we contacted TR Reiser of T-Man Performance and went over the details of the build. When H-D introduced the 120R, it was only a matter of time before aftermarket manufacturers developed parts to make The Motor Company’s biggest motor even bigger.Īfter we sent our bottom end to the guys at Darkhorse Crankworks, it only seemed fitting to reassemble the motor as a 124-inch beast. Perfect for installing wrist pins in pistons for two-stroke and four-stroke motorcycle, ATV, snowmobile and other powersport engines.
These two things are desired by Harley-Davidson owners, and most will go to elaborate means to achieve what they want.