No Oil Pressure

I have a 526 BAE V Hemi. Wet sump Dan Olson funny car pan, Plueger Pump, 16an from pan to pump, System One Funny Car Oil filter with #12 an from pump to filter and from filter to engine. I have experienced oil pressure loss on my second run for the last 4 outings. This entire setup is new. I have .065 restrictors in my rocker stands and have had the problem with both 50wt oil and 70 wt oil. With (15qts) 70wt oil my pressure drops from 90 to 95 @ stage to the low 30's by 1.4 into my run and then by 2.00 into the run I have about 18 to 19 lbs. With the 50 wt oil I have the same pressures roughly but the loss of pressure begins at 1.3 and 18 to 19 lbs by 1.6. I tried to increase the amount of oil to 21qts tonight and the same thing happened, I can overlay the Racepak Data to a pass with a different weight oil and less of it and it happens about the same time in the run. I stage at 6000rpm and am conservative about how long I am at stage rpms. I have checked the drains in the block and heads and they are free and clear. My crank and rod clearances are exactly what BAE recommends. It is definately pumping the oil to the top but I dont think it is a drain problem because when the oil is fresh on the first pass the pressure only gets down to about 32 to 35 lbs at the end of the 1/8th mile runs and gets worse with the thinner oil. My pressure never gets over about 125lbs and when I stage it has 901 to 95 and increases when I leave but drops rapidly. This is a Brad Billet Block. I am lost at this point and grabbing for straws. Is there anything in the pump that can cause this? How about the system one filter? Anyone have any experience with a problem like this before? I am sure I can overcome it by going to a dry sump and more oil but I feel that is just a band aid because there are others with my same setup and they dont have this problem. Thanks in advance for any input/help or ideas.

 

Adjust by-pass preasure

One thing to check would be the by-pass spring in the pump. 90 to 95 lb at stage rpm seem a little low, our car leave the starting line with about 130 to 135 lb and crosses the finish line ¼ mile at about 100 lb. In order to get these numbers we had to increase the spring pressure in the by-pass, adding 2 washers (harden) behind the spring. Also make sure there is not a small amount of debris causing the by-pass to stick open. In any case I would adjust the by-pass to increase the launch pressure up to about 140lb. Can’t say for sure if this is the problem but definitely worth checking.

 

The pressure has been everywhere from 150 all the way down to where it is now and the oil is in the top in roughly the same amount of time each pass.

 

We had the same problem. spun bearings on two consectutive runs. There's something about that new block that doesn't let oil drain down into the pan very well(my opinion). Put a dry sump on and it'll be okay, not just a bandaid. I don't think there are very many wet sumps on new bae blocks. Multiple people told us they had the same problem.

 

Make sure you have the correct screen in the filter , I think there is 3 different ones . Just curious , where are you taking the pressure reading from ? .

 

Pressure is coming from the fitting on the filter, and it does have the correct screen per system one.

 

I had a very similar problem and solved all oiling problems with a Doug Lee Pro pan. I went from using 12 quarts and losing oil pressure at 3.4 sec. into the run to using 7.5 quarts with no oiling problems, including at shut down. Call me at 620-663-4949 and I can put you in touch with Doug.

 

Here's something to think about, when the oil fills the valve covers it also goes into the blowback lines, now theres no air in the valve covers, so now you got a vacum in the valve covers and the oil just sits in the covers till you get back to the pits and it's all draned back to the pan, so you think it's ok, it;s like if you didn't have a big enough vent in your fuel tank, thats what i think and im sticking to it. or you might have a blockage in the frame rales or the blow back tank ( vent) P/S what happend to valve cover breathers, back in the day we didn't have all this oiling shit happaning.

 

oil

When you where saying over laying the racpack could it be a racepack prob. I watched a A fuel team at Columbus in the pits on the warm up racepack said no pressure to very little. They took the pump off checked everything put back on still nouthing. Then screwed a guage into the pressure line and it read fine sounds like could be more than that but may not hurt to check. Could be giving you a false reading.

 

Got something going. We had the same problem. we changed oil pressure sensos with nozzel pressure and found out we had a bad sensor,only bab thing the new sensors are 150.00