Barrel Shims - 85.5mm, .030"

Whether your motor lives or not can depend upon this little shim. Many people tend to overlook this part, but the shim controls the compression ratio. Compression equals heat and heat destroys motors. Take the time to figure your compression ratio and get the proper shims for that desired compression. Figuring compression ratios and getting the right shims is a long subject, so for help, just call. We find that 99.9% of all engines need barrel shims. Shims are sold in sets of 4.