13B Family

Cross-section of a 13B engine
Cross-section of a 13B engine – photo by Softeis

13B Family

This page is still under construction, and may not have complete information.

All Engines

Problems

  • Apex seals – carbon deposits will eventually wear out the apex seals and cause the engine to lose compression. Rotaries should go to the redline at least once per drive to blow out carbon deposits. A compression test at a Mazda dealership or rotary specialist is a necessity as part of a PPI. This cannot be performed like a normal compression test, as the rotary engine has a variable compression ratio unlike a regular internal combustion engine.
  • The cooling system should be closely monitored, as overheating can warp the rotary housing and cause the engine to lose compression. Common upgrades include bigger radiators and lower-temperature thermostats.
  • Engine repairs can generally only be performed at rotary specialist shops (which are few and far between) and Mazda dealerships.

AP

Usage

  • Mazda B-Series Rotary-Engined Pickup (Gen 2)
  • Mazda Cosmo (Series CD)
  • Mazda RX-4 (LA2)

13B-DEI

Usage

  • Mazda RX-7 (FC)

13B-MSP Renesis

Problems

  • Apex seals – Using higher-viscosity engine oil appears to reduce the likelihood of carbon buildup, as does mixing two-stroke premix oil in when filling the car with gas. Running seafoam through the engine also appears to help. Despite this, engines will still only typically last 50-70k miles before requiring rebuild/replacement. A common symptom of failure is difficulty starting the engine once it is warmed up, but not when it is cold.

Usage

13B-RESI

Usage

  • Mazda RX-7 GSL-SE (FB)

13B-REW

Usage

  • Mazda RX-7 (FD)