Hi Guys, In hindsight I should have asked you to include the oil brand and viscosity you are using in your alloy motors. Could you guys that have already responded to this thread, also include oil type and viscosity. Thanks. Cheers
Hi all, There is talk of loosing oil pressure at the top end of a run in Alan's 525 motor thread. I have experienced this while undertaking some brutal brake testing for engineering purposes. Thought I had prevented this with the gate and shroud around the pickup. Is the masterlube system a bandaid or is the lack of oil pressure a common problem? Thoughts? Cheers
This is what I got. Since new, start motor 100 lbs cold. After motor warmed up idle 40 lbs. Crack the throttle 80 lbs no problem. During burnout pressure will hit 80 lbs and fall to 60. Stage the car 80 lbs @ 2000 rpm. Launch the car pressure will drop slowly to 50 during run and stay steady up to 7000 rpm. Cross finish line hit the brakes pressure will dip to 20 and bounce back up to 40. Oil temp 185 deg water temp 190. On the return road 40 lbs @1500 rpm. Pressure not what we are used to but nothing to be alarmed at. My biggest question is....why such a drop of 30 or so lbs during the run? I am using a scavenger system and have tried 2 different ones, 2 different timing covers, multiple relief valve springs, which only change the pressure cold no change during the run. Different oil filters (system one vs. Napa gold) ,3 different guages, no change. I have approx 50 1\4 mile passes all between 8.93 and 9.10. The next option is to go to belt driven wet sump external pump any eliminate the stock pump. Now here is a new twist, yesterday, at Cecil County take everything I just wrote but change this part when I launched the car the pressure dropped to 20 lbs immediatley and stayed steady and everything was the same ie, oil and water temp and 40 lbs when I took it back on the return road. I did pull the filter and everything looked good, but I still need to open it up and verify that. That's my story. Comments welcome
Just came in from working on the car. Opened the oil filter nothing there. Dropped the oil pan spotless. I know the motor is not hurt,I just pulled the pan for my own piece of mind. As far as a possible windage problem, I have a windage tray covering the pick up area. So far I have talked to a couple others about what they have found but ther motors have only seen dyno time so far. I need to see what happens once the car is going down the track.
