I suspect so too, at least in your typical domestic iron. My aftermarket HV pump was rated at something like 10 gpm @ 3000 rpm. The OEM pump had half the vane depth. I would imagine many of your OHC setups have higher typical flow numbers since they're forced lubricate critical items in more places then the typical pushrod engine where one main gallery lubes the mains and the cam.
Okay ...that's totally possible...but there is reasonable cause to see a cause and effect relationship. I'll entertain alternative causes ..but so far no one has come up with any. (visions of Anthony Hopkins in Meet Joe Black, "You say you love her but you don't know what love is. She says she loves you, but she doesn't know who you are." * requires substantail associative ability for relavance)
Well, let's qualify that. We're not truly viewing the filter from a resistance aspect. We're viewing it as a pressure drop that we integrate to a resistance. Now the filter is a non reactive component ...but pressure drop is a reactive indicator. If you had a background in DC resistive circuits this would be easier to understand (or at least would have you asking the same questions that I am)...the only difference is being able to view it from a current flow perspective with a variable voltage supply that antenuates at a max voltage.
But my observations discount this to a great degree. Surely the use of a 20w-50 as opposed to a 5w-20 would have far more viscosity differences than similarities in a vast number of conditions (temps and flow rates) ..yet both produce a 3-4 psid in all modes when the peak system pressure is below the relief threshold. That is, the engine represents the majority of the pressure drop and the filter, integrated for all the reasons that effect pressure (visc, flow, etc.) are proportionally impacting the downstream environment ...and the differences in the filter's impact on the total pressure drop is not apparent and I'm leaning toward that they may be able to be measured in inches of water column.
I understand DC circuits. Equating hydraulics to electric circuits. As you know, pressure is voltage, current is flow, and a filter is a resister. Thus, the voltage potential measured across the resistor must increase as current increases. Right?
The problem here is that we do not know how accurate your gauges are. One thing you could try is to take a reading, swap the Pin and Pout gauge, then take the reading under the same circumstances again. Another problem with your gauges is that it is difficult to read down to the 1 psi. Then you are subtracting one reading from another to get PSID. of 3-4psid. A gauge error of 2 percent could cause the reading to change by over 1psi(2% of 60psi = 1.2psi). To get a reliable reading you really need a PSID gauge.
Correct. The twist is that electrical circuits are "demand driven". You have an available current limit and an applied pressure. It's not the same "view" that we need for a hydraulic circuit like this ..where the applied pressure is a result of vaiable current through fixed resistances.
True. Do you know how accurate any gauge is? How do you know?
I have done this...with identical results. That is, if any error or inaccuracy is in these two gauges .. it is shared equally between them. So, when comparing magnetude of readings, although the true amplitude may be in error, they should be good indicators. That is, 82 may not be truly 82 ..and 78 may not be truly 78 ..but they both say so.
I completely dissagree. It is true that our positive displacement oil pump is equivalent to a current pump. However, that does not change the way the resister/filter will behave with increased current/flow.
Great, and I aggree. If the magnitude is off a bit it does not really matter. I still question the "precision" of the gauge. The smallest increment on the dial is 2psi. It is diffucult to read much more accurately than the nearest 1psi. So, it is difficult to be very precise with those PSID readings.
I know you have the data. But, I find this impossible to believe. The PSID across the filter MUST increase with the higher viscosity fluid. However, looking at my charts of "friction loss for viscous liquids" (Cameron Hydraulic Data) I see that if you double the viscosity you only increase the resistance by about 15-20%. (for turbulent flow). Looking at viscosity data for 5W20 vs 20W50 the 20W50 is twice as viscous as the 5W20 at 100degC. So your 3-4 psid for 5W20 should increase to 3.5-4.5 for 20W50. DO you think you can read the gauges accurately enough to detect that? (no sarcasm intended).
It looks like it should be laminar.
Well, you can't completely disagree ..since I said the same (limited) thing here
Which is does, until we open the relief.. if the same model applied when I saw 10+ PSID ..I would see elevated downstream pressure as well. The elevated PSID would normally imply MORE flow through it ..when we know, simply due the relief setting being reached ..that it is less. (just give me a flicker here, pal ..just one dim glow that you're attempting to see what I'm talking about.
I agree with this.
I'm thinking you are correct. More bypassing results in less increase of flow into the filter... I'll think about it some more and try to update the chart as necessary.
Yes, I think it would be correct then.
quote:
quote:Originally posted by Gary Allan:
You have to work backwards from the normal DC models. I've never seen an electrical "current pump" that you can hook up to a set of resistive loads and produce a resultant voltage.
Now you have
They are easy to make and not all that unusual.
The last time op amps came up (maybe a couple of years ago) you stirred some thoughs in my head. I was still in TTL "back in the day" ..but remembered how relatively simple a op amp was in the LSI chips (the
