Oil pumps again...

Bewy said

Not joining/commenting on the above 'debate', but......

There are odd numbers bandied about for oil pump flow etc. The BB Ch must have one of the most restrictive inlet flow paths for the popular V8s. Long p/up tube, only about 3/8" internal diam. Then, when the oil gets to the block it has to negotiate a torturous path around a 90* bend with sharp edges. Sticking a HV pump & HP spring at the end of this invites sucking air into the system. Ch wisely increased the p/up diam for the hemi. As a comparison, the stock 60 lb pump on a Pontiac has a short J shaped p/up, about 6" long, 3/4" OD & 5/8" ID, smooth flowing.

Click to expand...

Exactly. The inlet side of the pump is THE critical restriction on any pump. That’s why a mid or rear sump pan with a front mounted pump is stupid. Same as a rear mounted pump and a mid or front sump pan.

The longer the pickup tube, the greater the diameter it needs to be to reduce intake restriction.

Also of note is the difference in the pump output between a spur gear pump and a gerotor pump. The gerotor pump needs a greater cross section pickup tube by the very nature of its design. And the out put of the spur gear pump is smoother than the output of the gerotor pump. IMO, the HV pump helps to smooth the output of the gerotor pump.

High pump speeds and a restrictive pump inlet is a bearing killer.

There is more to lubricating these engines than making a blanket statement that a HV pump is a power loser.

Of course, when you don’t do your own testing and you only believe what happens in one’s one head then you continue to make the same mistakes over and over.