Started cleaning up the engine and when I removed the fan pulley this water pump was under. Is this OEM? I have had a few engines apart and never seen one like this.

Doesn't look OEM to me. All the water pumps I have seen have a recessed (thinner section) area around the bolts. Where your bolts are at the same height as the pump body. If you know what I mean...

Looks like some sort of aftermaket unit.

Chas

I'd be interested in seeing the impeller blades. Never seen a casting like that before.

My 2 aren't anything like that.

Yes, I too would be interested in seeing the impeller blades. Here is where I go out on a bit of a limb (pier?) and say that the factory pumps has cast iron impeller blades whereas a lot of the cheaper aftermarket pumps had pressed steel ones. The cast iron types result in less cavitation than the pressed steel ones at higher RPM's - he said...

I can't tell you the last time I used the word "cavitation" in a sentence! Any liquid dynamics PHd's care to pour over their notes?

That looks strikingly like the pictures in the 1970/71 Engine Service Manual. I have never seen one like that in person before though. What year car is that engine from?

Here is a pic from another post of original service manual photos:

Edited June 14, 201311 yr by er34gtt2000jp

Yes it does look like it is OEM from that photo, the motor has a cast date stamp of June 26, 1970 and the build date of the car is Aug 1970

That looks strikingly like the pictures in the 1970/71 Engine Service Manual. I have never seen one like that in person before though. What year car is that engine from?

Here is a pic from another post of original service manual photos:

[ATTACH=CONFIG]63980[/ATTACH]

EuroDat,

My old water pump seems to have recessed bolts. The pictures are of the water pump that was on my car that I pulled off a few weeks ago as it had started to leak slightly. It says GMB on it which doesn't seem to relate to Nissan as far as I know, from that it must be aftermarket? I can't tell if the impeller is iron or steel. The engine I have has no serial number, I read that means it was a replacement engine from Nissan, don't know what that might mean in terms of water pump.

impeller:

Edited June 15, 201311 yr by Mikes Z car

That is a stamped steel impeller.

EuroDat,

My old water pump seems to have recessed bolts. The pictures are of the water pump that was on my car that I pulled off a few weeks ago as it had started to leak slightly. It says GMB on it which doesn't seem to relate to Nissan as far as I know, from that it must be aftermarket? I can't tell if the impeller is iron or steel. The engine I have has no serial number, I read that means it was a replacement engine from Nissan, don't know what that might mean in terms of water pump.

impeller:

[ATTACH=CONFIG]63988[/ATTACH]

I think mine is the same. Can't see much because its covered by the pulley. The recessed areas seem the same and I can just make out the ridged section, but could not see the GMB stamp because of the pulley.

I wonder what GMB means. Maybe Nissan had contracted manufacures to make these or its aftermaket?

Chas

GMB was started in 1976, GMB

GMB CORPORATION

150-3, Handa, Kawanishi-cho

Phone: +81 745441911 SHIKI-GUN, NRA 636-0295 Japan