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Oil Pump Mods - Max Effort

FreeEMSFred said:
I spent some time measuring my block this evening and although it can't hurt, I have my doubts about the benefit of opening up the feed tube to 13mm ID (matching pump and block) from 11mm ID. Why? Because the gallery from the pump entry to the block and the filter is a mere 10.0mm, and to improve this you'd need to bore it out from the bell housing end. Not a minor job, for sure. Is this in the plans? Or just a case of "may as well make it better while fixing the clearance issue"?
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mini surge tank/swirlpot of sorts>?
 
CaseyHooligan said:
I'm no Fluid Dynamics Phd, but in my experience it does help to improve some areas of a system, even if they aren't the biggest restriction.
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The real improvement only arrives by pushing the point of lamina flow further up the RPM/flow range and delaying the onset of turbulent flow. For a given perfect tube you will reach turbulent flow at some flow level and throughput will fall drastically despite raising pump end pressure, lowering bearing end pressure, and causing more bypass (where the spring comes in). Until that things are fine.

Smoothing things up definitely helps push that point higher, too. But the existing tube is fairly smooth, and 1mm larger ID than the bored out gallery. The worst parts aren't the 13 to 11 to 13 steps, they're the sharp right angle corners in a few places.

And you stated you were interested in low RPM flow. Although it's true that any improvement will help push pressure drop down, final pressure up, and flow up with it, measuring the improvement at the lower RPM non-turbulent end of the flow spectrum might be a challenge ;-)

If you did bore out the lower gallery to 13mm and retap the end for a bigger bung then yeah, there'd be a benefit in overall flow (only significant if the stock system was breaking into turbulent flow at some point, though), provided you followed the improvements through the filter input and output (easy enough to do). The upper rail is bi-directional so wouldn't need much touching and can almost certainly out-flow even a 13mm pump-to-upper-rail connection:

PI * 5.5 * 5.5 * 2 = 190.1 sq mm
PI * 6.5 * 6.5 = 132.7 sq mm

Not taking the non-uniform flow rate, nor the non-even split in flow to the two halves, into account, that's a clear win to the upper rail over any lower feed improvements.

Max effort: Bore that lower gallery out to 13mm and retap the end! Then radius all 90 bends. Then rest assured you've got zero pressure drop issues at higher RPM :-)
 
FreeEMSFred said:
The real improvement only arrives by pushing the point of lamina flow further up the RPM/flow range and delaying the onset of turbulent flow. For a given perfect tube you will reach turbulent flow at some flow level and throughput will fall drastically despite raising pump end pressure, lowering bearing end pressure, and causing more bypass (where the spring comes in). Until that things are fine.

Smoothing things up definitely helps push that point higher, too. But the existing tube is fairly smooth, and 1mm larger ID than the bored out gallery. The worst parts aren't the 13 to 11 to 13 steps, they're the sharp right angle corners in a few places.

And you stated you were interested in low RPM flow. Although it's true that any improvement will help push pressure drop down, final pressure up, and flow up with it, measuring the improvement at the lower RPM non-turbulent end of the flow spectrum might be a challenge ;-)

If you did bore out the lower gallery to 13mm and retap the end for a bigger bung then yeah, there'd be a benefit in overall flow (only significant if the stock system was breaking into turbulent flow at some point, though), provided you followed the improvements through the filter input and output (easy enough to do). The upper rail is bi-directional so wouldn't need much touching and can almost certainly out-flow even a 13mm pump-to-upper-rail connection:

PI * 5.5 * 5.5 * 2 = 190.1 sq mm
PI * 6.5 * 6.5 = 132.7 sq mm

Not taking the non-uniform flow rate, nor the non-even split in flow to the two halves, into account, that's a clear win to the upper rail over any lower feed improvements.

Max effort: Bore that lower gallery out to 13mm and retap the end! Then radius all 90 bends. Then rest assured you've got zero pressure drop issues at higher RPM :-)
Click to expand...

Blind now from all the science...
I totally agree with your determination in regards to the lower galley cross-sectional area.
But what about the stock oil pump transfer tube's interface to the pump? The oil leaving the gear pump cavity runs right into the end of the transfer tube!!! that point right there has got to cause significant turbulence(at any velocity). So increasing the transfer tube's cross sectional area, plus reducing the tube interface area change will likely slow velocity and reduce turbulence, at least before the oil gets the the block.

I'm all for theoretical simulation, but I already know oil system efficiency is not a critical issue for most so I'm just optimizing flow and addressing a few other issues here(main stud clearance, oil seal failure).

I'm a proponent of real-world experimentation, I'll just have to wait and see if all this makes a difference when I get this engine running.
 
Tuff240 said:
Track was literally 5 minutes away from our shop. I drove race cars to the track on the public streets several times. :oops:

Not as elegant and sophisticated as Casey or Fred would do, but it's simple and works. KISS ;-)
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Tuff, I'm totally taking a page from your book and adding a kick-out on the passenger's side.
 
CaseyHooligan said:
Tuff, I'm totally taking a page from your book and adding a kick-out on the passenger's side.
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Cool, I look forward to what you come up with. I'm really enjoying watching your engine build thread. One of the best redblock builds here ever I think. At least as far as thought and care go. Some of us may agree or not agree with some things, but no doubt the level of detail is impressive to say the least.
 
Just sticking my head back in here after being buried by life and other projects.
I'm starting to wind this engine build back up so I can get it on the road.
I'll post more soon, promise!
 
I finally started the process of building more of these oil tubes. Just received the machined fittings, enough for a dozen assemblies. In 4130 ChroMo.

EbxbgBAbjZyl5qKJVSlLul84WBbLYWJ1gR5frRuDh_JOQN1ECZawV3-X8sxZ9LXrwcYAJQ0cdmUR9tpPxhZ0p501_W-mx1STidV9ZVIZRPP61zWcDzCgXJ7heqwmvV9AHGOkvAwEyd086M2pZ7D74YCKBiwyNJMm3ghAa1wbteGsaqVj0T53fxXCzD8Z49eEvX1_unhuyEO-JNoQrXm03VQ08OWA-vwhQbR43Nh3pkl846KnaY_m6EncZldJAwnv9EyxjD8N2O8_LTi9M4I1a2ki-SYTEwAJyTEQTsdqiai_jfRaGRHCyt9UZ97SYcwP3dxQYn6VEWuUrEMTPhksgbCKGuBWFqKnqmlm27PJi2eKJ6i4Zoc459hg5mh7DaOQOFiAqZ898q0UuPtwJgZW-Me68qw_I7IbVOA239DfKl9nPDfz_oMQTgLvd4fQrECtaAlneJqXSSLYFPfo78-N491Q8ojxVJK87IhWGvYuf7NWouUjjgLqtIlvHYTt1zu6Pm8YVmQdlrME02ikHhE3E7REZ3wp73hIgYaHUv-gChbjwJr-b5EivSjSFFJwCUKUHVvbDKpvIEcwcfEeIJgfDINpRWuoq5fdPBybAp6BtSWlHCcUuNWJwAjm3lvv6dY6YA9XkLA2m0sYGyj8VPVRkBv44sHUF8aGrDZZvaYFPePxRcHhO4dC7Fi0yI1DSjcAMlJFqcDjfNUD4i9BwNAH2aLn=w992-h558-no


Waiting on the tube bending, Then I need to TIG them together.
Hope to have something to show in about two to three weeks at this rate.
 
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