Review on ACL 4B8351H STD Standard Performance Bearing by Eddie Simpkins

Even with the suffix STD bearings they are too big. I've been waiting to write this review until I broke my rebuilt engine. When I plastigauged the old bearing clearance at 100,000 miles it was still within spec for the Miata 1.8L BPZ3 engine (0.8k to 1.4k) at around 1.2. I put these bearings in and remeasured and measured 1 mile on all the freeways. I also installed ACL roller bearings for the cranks and they were above spec as well. While the engine is running normally there is a little more noise than the original and I assume this is due to these bearings. If you advertise a bearing as a standard size, it must be at least within specification.