Is this the big nose crank?

[mathia]

Thanks for the detailed info naprotejay! Yep, mines a big nose. Good call on ID'ing the oil pump. Finally got the time belt pulley off and it measures 27mm.

Sounds like it's not really worth worrying about if you've got a small nose crank in a BG chasis car. But when ever a manufacturer goes to the trouble to update a part, I've got to think there was something significantly wrong with the original design, so I'm happy to have the big nose.

Now I can get back to getting this motor ready for its GTX turbo build up

[naprotejay]

I have to say that my GTX motor from Japan came with that miata.net refers to as the long nose.

not doubting you Alex

maybe in the JDM market, Mazda had a 'long-nose' fix/replacement for failed 'short-nose' BPT cranks.....?!?

[Lex]

I'm actually inclined to think that the "fix" was incorporated in BP motors from the get-go. The long nose and full keyway insertion that is. Perhaps only the B6 had the short nose?

[TurboProto]

Hey Matt you have nothing to worry about the stock crank failing. Its the rods you need to worry about. The stock bp05 will hold the boost just fine as long as you tune the timing correctly. Ive herd of fully stock blocks that are boosted that have put out in the 300hp range. Not too sure on how long that motor lasted!