You're saying the oil pump needs "backpressure"?
I had never considered it, but immediately it doesn't make sense to me... can you explain further?
The oil passes from the pump, into the housing, through the cooler hole, through the filter, through the threaded post, past the stock OPS, into the oil gallies.
I respect your knowledge, and you have me worried I'm missing a big concept here.
The pressure gauge won't be useless. All of the other gauges I've seen are placed in the same part of the circuit as all the bearings, so it reads what the bearings see. Putting this right by the pump would be incorrect, as would be putting it up on a cam bearing.
Matter of fact, the Probe OPG threads right into our OPS spot.
Also, in the pic solo posted, the oil cooler is absent on later models, no cooler hole.
I don't think you are correct. The pump operates independently of the rest of the system. You could run the pump on a bench with zero restriction on the output, it would work fine, its just a gear pump.
The pressure relief is built in so the pump doesn't grenade if it gets blocked (some people shim this, I KNOW this is a terrible mod with NO benefits whatsoever, tell your friends)
As long as it has that to regulate the max pressure, and no limit on minimum output pressure, nothing will change as far as the pump is concerned with what I'm doing. The bearings will now see the full power of the pump at all RPM's (assuming before that that restriction was the main bottleneck).
A throttle on a positive pressure system will only regulate the high side pressure, the low side pressure depends on the flow rate on that side(depends on another throttle).
I think I am correct.
Maybe you're thinking that the bearings are on the same side of the pump as that throttle? Thats what it sounds like now that I think about it... But that doesn't make sense, because then it would be in parallel, hurting min pressure at bearings, and would indeed render gauge useless, as well as pump unfiltered oil to the bearings...
all of the pressurized oil passes through that small hole before it hits any bearings. It is the a series component in the parallel system of bearings.
Imagine you're blowing backwards through an exhaust header. You can get x amount to each port. Now put a throttle right next to where you're blowing into, what you can get to each port must now pass through that throttle.
I think its incorrect that the bearings must see a minumum pressure... if they allow more oil past them, thats great assuming its healthy flow and not poor clearance flow. Think in reverse, why would you want to restrict the oil on its way to the bearings? I can't fathom any reason...
Dan, I have the pickup diameter in my thread on PT...
http://forums.probetalk.com/showthread. ... yan+oiling
~17mm
Sorry, if you didn't want to read all of my brain-babble:
-the oil cooler restriction is a restriction that all of the oil sees, it is a series component before the parallel branch of the oiling circuit.
-the pump does not require backpressure
-throttling the oil on the way to the bearings will not increase the pressure at the bearings.