Oil pump drive - to key or not to key, that is the question!

[Mettler]

As most of us are aware by now, the oil pump drive does not have a corresponding keyway/key on the crankshaft. I thought this worthy of its own thread.

Some of us believe this to be a design flaw, while others do not.

Personally, I have faith in Nissan's engineering that they have done it this way for a reason... and the fact that the crank bolt is torqued to 370NM from factory would suggest one hell of a clamping/friction load on the oil pump drive. It's not exactly going to spin unless your oil pump itself siezes up for whatever reason, by which time you're already screwed.

The question is, for those of us presently in the throes of a build... do you think it would be wise, or overkill, to get a keyway machined in?

Discuss.

[ultrapulse]

I'm not bothering. The clamping pressure on even less than that front pulley torque would be very high. There shouldnt be much load on it, if there is then theres that lightweight chain...So yeah i trust my front bolts done up.

[elwesso]

Personally I wouldnt mess with it.. Reason being that you look at how the rest of the motor was designed, if a key for the oil pump was even remotely necessary they would have certainly given it one...

[maxnix]

Q45tech has stated the pump is left unkeyed so that at very high resistance levels (extremely cold oil) the pump willnot fail as if it were keyed. In normal operation, there is no need to key. In extreme conditions, there is ample reason not to key.

[elwesso]

Ahh very nice Brian... That makes perfect sense!