Baffling a pan for land-speed vehicle.

[Jetmugg]

OK - I am about ready to re-install the oil pan and windage tray on my 1.5 turbo engine, which is powering a Dodge Rampage (for those of you not familiar with my project).  This is for a land speed record attempt, which is straight line racing only.  There is no need to control oil during cornering.  I only need to ensure a good supply of oil to the pickup, which is located about 2" in front of the oil drain plug, and about 3/8" up from the floor of the pan.

Anyway, I now have the opportunity to weld some baffles into a stock OEM oil pan (from a 9A 2.0L engine).  The oil pan is a blank slate at this point, with no baffles of any kind.

What kind of baffles would you suggest in order to ensure a good supply of oil at this location?

Thanks in advance.

Steve.

[Jetmugg]

OK - here's what I did...

I put the turbo drainback  fitting between two bolt holes on the pan rail, which unfortunately pointed the drainback flow at one of the louvers in the windage tray.  There would have been a lot of turbulence in that area, so I made a short section of curved tubing to direct the return flow towards the passenger's side of the pan. 

Then, I made a simple baffle plate to isolate the "pool" on the turbo return side in an attempt to contain any potential frothing from the turbo return line.  There is a gap of about 5/8" clearance in a window that I cut into the lower portion of the baffle for liquid oil to drain back to the main chamber of the pan.



I had to grind some clearance in the top portion of the baffle so the windage tray will clear.  Here it is with the windage tray in place.

[air-cooled or diesel]

beautiful windage tray; the problem I have is this; the turbo return looks very low in the oil pan/level wont it back up farther into the return? its pretty far down in the pan/oil level.
the welds around the return are globby, a neater weld will typically seal easier, make sure you get the slag off(yes mig welds do have slag), id tend away from painting me thinks, most paints will bleed into the oil-etc.

[Jetmugg]

I know what you are saying about the welds.  They will be cleaned up before bolting the pan on.  I will ensure that there is no loose material, or anything that might work loose.  The inside of the pan will also remain unpainted.  I'm not worried about bare steel rusting on the inside of the pan.

As far as the location of the return fitting - it has enough clearance for the nut that has to be threaded onto the outside of the pan, but not a whole lot more.   The return "elbow" you see there is not the sealing surface against the pan.  The weld bung was welded to a hole drilled in the pan first.  Then, the little elbow was welded to the inside of the pan as a "deflector".

Steve

[Jetmugg]

Looking at an OEM turbo oil pan, I think the return inlet on mine is probably at the same location, or possibly higher, than the OEM unit.

A dry sump setup continues to haunt my dreams.

[air-cooled or diesel]

I doubt rust is a big concern; as long as the turbo return has enough level where the return oil doesn't back up, cause if it backs up into the turbo, well that's a no-no.
whens the next run/'race'.
get us a pic of your oil pump pick-up, I guess you've extended it.

[Jetmugg]

I'm going to try to get a dyno session before the end of July, then it's off to Bonneville on August 6th.

I may be wrong, but I've assumed that since the oil going to the turbo is under pressure, that the return will be pressurized as well.  I guess the main concern is introducing bubbles into the oil pan, which could lead to frothing.  I'm hoping that the baffle and the windage tray will minimize that effect.

Steve.

[theman53]

The return is not pressurized, more gravity type. From what I was told that is why you need a bigger return line than the feed. I think with the bigger pan and windage tray alone would be plenty.

[Gizmoman]

I think the baffle you have is OK. Possibly one more in the center with the bottom edge about a 1/2 inch above the face of the pick-up would keep the oil from flowing backward as you accelerate (if that's your concern).

As for the turbo drain, I agree with theman - no pressure on the return line is the goal. You are correct, if the drain was the same size as the feed, there would be pressure which is not good. There is no such thing as a drain line that's too big. You want the pressure to drop to zero as soon as the oil has passed over the bearings.
My drain (Holset 200) has a 5/8 ID and seems to work fine.

[Jetmugg]

My drain is also 5/8 ID (-10 A/N).  I took another look last night, and there's not much more room to get the drain fitting any higher.  I could have gone another 1/4" up possibly, but wanted to maintain some clearance for the A/N fitting that screws onto the bung.

I understand about having the larger drain tube diameter, but just want to make sure I understand the internal plumbing of the turbo from an oil standpoint.  I have a -6 A/N line supplying oil to the turbo, that is fed from a drilled and tapped port on the top of the oil filter adapter.  That line supplies pressurized oil to the top of the turbo bearing.   The drain line obviously runs from the bottom of the turbo to the fitting on the pan through a -10 A/N line.

That's a good idea about another baffle with the top of the "window" slightly above the pickup level.

If there is pressure on the inlet side of the turbo oil port, then it seems to me that the oil in the return line will be forced into the pan, even if the oil level in the pan is higher than the drain fitting.  It may cause aeration of the oil in the pan, but I think it will have to get into the pan, pushed by the pressure being supplied at the oil inlet fitting on the turbo.

Unless the block itself was drilled and tapped for the return fitting, I just don't have a good way to move the oil return any higher on the pan.

Steve.

[Gizmoman]

Sounds like your drain line ID is good. The #6 feed line seems excessive but it all depends on the smallest fitting ID in the circuit. I agree that the line will have pressure from the feed - it just needs to be as low as possible to keep from pushing oil past the "seals" in the turbo and into your intake or exhaust. My K-14 didn't even have a true seal on the compressor side (not sure about others) and any restrictions in the return pushed oil into the intake. Now I'm running a Holset and a very simple and "open" drain line.

Where to drain back into the engine (above or below the oil) has been debated ad nauseum. All I can say is mine is below the oil and I've had no issues. I'm not competing with anyone though - here, or on the salt . I think where you have it now is fine.

Thinking more about the baffles, I wonder if leaning one way or the other (forward or back) would provide better cavitation resistance?"

[theman53]

I think you could get an AN6 to AN4 connector and solve another part of your problem. My turbo said no bigger than JIC/AN 4. I had a 6 on it which I lost about 15psi of oil pressure when it was the bigger one because it was flowing so much. Check to see what your turbo requires, and note that the 6000 rpm of the diesel it will not need as much as a higher revving gasser.

I know the pressure loss is not a big deal, but all that extra oil being pushed in could have been running that smaller pan dry easier.

[Jetmugg]

I'll take a look at the A/N fittings and lines again this afternoon (first, to make sure my memory isn't tricking me).  You are correct, Lucas - I could use a "stepped down" adapter fitting to restrict oil flow through the turbo.

Every extra HP will help.  Over a 3 mile run, I think I'll reach my terminal velocity.

I have another transaxle that I plan to swap in before Bonneville, which will give a net 2.47 final drive ratio, as compared to the 2.76 top ratio that's in the current trans.  That will move the "record" speed closer to the HP peak of the engine in terms of rpm's, and may help with the oil issues as well.

Steve.

[theman53]

depends which way you need to go but here are some ideas

http://www.ebay.com/itm/AN-FITTING-UNION-REDUCER-AN-6-FEMALE-to-AN-4-MALE-/250358714318?pt=Race_Car_Parts&hash=item3a4a8acfce&vxp=mtr

http://www.ebay.com/itm/AN-FITTING-UNION-INCREASER-AN-4-FEMALE-to-AN-6-MALE-/250351237897?pt=Race_Car_Parts&hash=item3a4a18bb09&vxp=mtr

[air-cooled or diesel]

I hope you haven't welded on an extension for pump pick-up yet; I was going to say, that screen at pick-up has to go; if you can see it -or get to it to clean it, its counter productive. I figure you may have your pan off often, so a screen wont do very much; but if you cannt clean it when you have pan off, well that's obvious; if you really feel the need get a screen and weld to bottom of pick-up; but I doubt for what your doing one is really necessary. its just there as a 1st line of protection for the pump against big debris, pre-filter. if you have the pan off after every race I doubt one is doing very much.