Triumph Racing Primary Crankcase Breather Stub By CBS

  • Sale
  • Regular price $ 26.95

A popular racing mod back in the day on pre-1970 Triumph 350, 500 and 650 unit twins was to allow the engine to breathe through the primary side case. Models from 1970 and on already featured this design however, pre-1970 models did not.


If your engine features the timed inlet cam breather and you would like the engine to breathe through the primary you would have to drill (3) small holes near the bearing housing...


I won't get into detail regarding the mod as you can look online for more info that has already been covered... This aluminum plug will thread into your top engine case which will replace your filler / inspection plug and you can then run a breather hose on the stub.


Our breather plug measures (1" X 16) and accepts a .750" I.D. (3/4) breather hose (not included) - Made in the USA exclusively for CBS


Breather stubs are sold each as pictured - for racing motors applications only! 

  • Made in the USA by Classic British Spares, Inc
  • Replaces OEM part number is 70-0732, E0732, 57-2166 and T2166
  • Free shipping in the USA (lower 48)