m55hv pump in stock pan - what oil pickup?

[shiftpro]

Thank Art.
Don't believe I ever heard of setting pump clearance, but makes total sense.

 

[74 Shortbed]

Thank Art.
Don't believe I ever heard of setting pump clearance, but makes total sense.

You're welcome, hardly any of them are the same, I've seen them with over .004 out of the box, that's a hell of a lot of slippage and loss of flow..

 

[shiftpro]

If you use a speed handle to prime the motor by hand, you will feel the difference between the two and it's very noticeable.


Right, I do it all the time big or small block, but all that does is smooth out the flow and eliminates turbulence at the pump, passages are still the same size as bearing clearances, so the volume is still the same.


Well, that depends on how deep of groove you cut, lol, just the slightest bit will flow enough oil without affecting the volume, also if you clean out the center slots in the valley helps too.

The two galley plugs are already drilled .035 from the factory to release air and to lube the chain, any bigger and the oil gets whipped around and gets aerated, not the best thing. As I mentioned before, set the clearance right (.0025) it makes the pump more positive which will flow more oil and an increase in pressure.

Art I found this article about grooving the bbc pump. Are you familiar with this?
http://www.chevelles.com/forums/18-engine/397733-bbc-oil-pump-mods.html

 

[shiftpro]

Actually my computer was stuck and I couldn't scroll down to the comments about the groovin mod.

 

[74 Shortbed]

Art I found this article about grooving the bbc pump. Are you familiar with this?
http://www.chevelles.com/forums/18-engine/397733-bbc-oil-pump-mods.html

Yep, that's to prevent cavitation at high rpm's, a necessity on road racing and marathon stuff, if you ever see the needle on the gauge bouncing around at 7500+ that's what's going on..