Oil Pump Dyno

[Blueoval77]

ok , so I am giving big points for this thing even if it didnt work as well as it does.... Ironically me and a buddy of mine were having this conversation a  few months back how this type of pump was prone to aerating oil and yet we all still get in line to buy and install them. As I recall there is a pump design that doesnt do this but my old brain isnt giving me the answer at the monent...

[427John]

A pump design that doesn't recirc bypass oil back into the suction of the pump and instead dumps it back into the sump will be less likely to aerate the oil,but pump manufacturers know that a design with a dump line like that are subject to having a valve put in it by the end user and getting accidently closed or plugged up somehow and causing the pump case to get split open since it is a positive displacement pump.So it is very common for positive displacement designs to have a relief/bypass port that dumps it directly back into the suction to preclude the possibility of the relief path getting blocked.The unfortunate part is that in relief/bypass mode it tends to aerate the oil.While the argument could be made you don't have to worry about that inside of an engine ,I don't see auto manufacturers seeing the need to reinvent the wheel.

[Barry_R]

When I was at Holley we were working on the gerotor style fuel pumps - eventually sold under the Volumax name.  The lower volume pump would smoothly and cleanly deliver 170 GPH with 1/2 inch feed and outlet lines.  When they stepped up gerotor size and motor to get a 250 GPH pump it got noisy as heck and cavitated badly.  Adding a second feed line calmed it down and it went well beyond the target volume quietly.  The "cure" is inlet passage size/shape/etc. 

[Blueoval77]

Oh thats not a can of worms at all Barry.......

[475fetoploader]

I ran a Volumax 250 for several years, it did have 2 supply lines, and I couldn’t here a darn thing in that car without mufflers. The pump didn’t lose a pound through the lights at 135 though.

[427John]

Will your oil pump test  rig accept a 429CJ/SCJ dual entry oil pump?If so it would be interesting to see if it does the same thing.Maybe ford engineers addressed this issue with the next generation,but didn't see the payback for the FE since it was near the end of its life in cars.

[Barry_R]

I ran a Volumax 250 for several years, it did have 2 supply lines, and I couldn’t here a darn thing in that car without mufflers. The pump didn’t lose a pound through the lights at 135 though.

Should not have been that loud.  I ran one for many years (one of the first ones I suspect).  Car is still plumbed for one, but I went Aeromotive A1000 when I went EFI. 

[oldiron.fe]

  is it possible to observe the oil moving to the pickup before/after bypass happens and any aeriation occuring -- bypass pressure vs point of aeriation rpm occuring --gerotor vs spur gear / drive spur gear with anti-cavation slots ?   GREAT TOOL @ EFFORT  thanks  much  p.s. at bypass is pick covered in (good) oil

[cammerfe]

It may be worth mentioning that the return line in a dry sump system is set so that the oil entering the tank is spun around the inner circumference of the tank for the supposed reason that the centrifugal force helps remove entrained air. And depending on whose tank you're talking about, there are other features in the tank to help remove air as well.

KS

[WConley]

Will your oil pump test  rig accept a 429CJ/SCJ dual entry oil pump?If so it would be interesting to see if it does the same thing.Maybe ford engineers addressed this issue with the next generation,but didn't see the payback for the FE since it was near the end of its life in cars.

For a different engine family I would have to machine a new pump mount block for the rig.  Certainly possible if it makes sense.  Still lots to learn from the FE pumps, and I do have a pretty cool trick up my sleeve to address the cavitation issue.  More on that in the near future.

[WConley]

It may be worth mentioning that the return line in a dry sump system is set so that the oil entering the tank is spun around the inner circumference of the tank for the supposed reason that the centrifugal force helps remove entrained air. And depending on whose tank you're talking about, there are other features in the tank to help remove air as well.

KS

Ken - I actually made a return manifold kind of like you describe.  It's acrylic and the oil gets flung around the top, dissipating its energy before falling back into the pan.  You can kind of see it in this picture.  The original intent was to get the oil back into the pan without flying all over the place, but it may help with the air bubbles too as you describe.  You can see the oil flying into the left edge.  It goes all the way around that top channel:



Oldiron.fe - Yeah it is possible to look at the oil in the pan, but it seems easier to observe the clear pressure lines.  It becomes quite apparent when the cavitation starts to occur.  You actually get a foggy mist forming from the oil dumping back into the pan!  Yes indeed the pickup has plenty of oil during bypass.  I made sure of that, and the graph I posted shows a steady 86 psi pressure up at those speeds.  The pressure would have certainly been fluctuating if it was sucking air.

[427John]

It may be worth mentioning that the return line in a dry sump system is set so that the oil entering the tank is spun around the inner circumference of the tank for the supposed reason that the centrifugal force helps remove entrained air. And depending on whose tank you're talking about, there are other features in the tank to help remove air as well.

KS

KS your absolutely right on the tangential entry on the dry sump tank using centrifugal force to dissipate aeration being effective,we used centrifugal lube oil purifiers to remove contaminates such as water ,metal shavings and dirt ,but was equally effective at dissipating aeration,there was a viewport and you could observe how clean and air free the oil was coming out.

[frnkeore]

The return line entry, isn't a centrifuge but, it does give wall area to dissipate the oil and let it flow back, into the reservoir, with less energy and air. Many tanks, also have a screen at that level to also help decrease aeration and to be a upper baffle.  In the 60's - 70's, there were all kind of tank shapes, with the return just dumping into the top in many different ways, most all running w/o any problems.

Modern tanks are tall and narrow and don't need much baffling, because of that and since air is much lighter than oil, aerated oil, doesn't have much chance to get to the pickup. We are talking about a column of oil, 8" in diameter, 12 to 14" tall (10 to 12 qt).

All that beside the point for this. In a car, with a pan, you have lots of aerated oil, off the crank, landing on top of the oil, above the pump pickup.

This is a great project and can benefit everyone running a pan, if the cause can be found.

Something else that could benefit us, is the actual oil flow used in a FE at some pressure standard and .0015 and main and rod clearance, then .003 or even .004. It think it would show whether or not we need HV pumps.

[blykins]

The return line entry, isn't a centrifuge but, it does give wall area to dissipate the oil and let it flow back, into the reservoir, with less energy and air. Many tanks, also have a screen at that level to also help decrease aeration and to be a upper baffle.  In the 60's - 70's, there were all kind of tank shapes, with the return just dumping into the top in many different ways, most all running w/o any problems.

Modern tanks are tall and narrow and don't need much baffling, because of that and since air is much lighter than oil, aerated oil, doesn't have much chance to get to the pickup. We are talking about a column of oil, 8" in diameter, 12 to 14" tall (10 to 12 qt).

All that beside the point for this. In a car, with a pan, you have lots of aerated oil, off the crank, landing on top of the oil, above the pump pickup.

This is a great project and can benefit everyone running a pan, if the cause can be found.

Something else that could benefit us, is the actual oil flow used in a FE at some pressure standard and .0015 and main and rod clearance, then .003 or even .004. It think it would show whether or not we need HV pumps.

We certainly don't need HV pumps.  I've been using standard volume/standard pressure and standard volume/higher pressure (B) pumps for a very long time.  My 352 had a B pump in it and upon teardown, I didn't see anything that stood out to me indicating I needed a high volume. 

I will also tell you that a standard volume, high pressure pump will feed VERY excessive clearances.

[blykins]

ok , so I am giving big points for this thing even if it didnt work as well as it does.... Ironically me and a buddy of mine were having this conversation a  few months back how this type of pump was prone to aerating oil and yet we all still get in line to buy and install them. As I recall there is a pump design that doesnt do this but my old brain isnt giving me the answer at the monent...

Titan.  But it's a $1000 pump.