I have a fresh built 302. Stock crank, rods, .30 over speed pro pistons, 192 intake & 160 exhaust, roller rockers, screw in oil plugs, Comp Cam 280H, .10 under mains and rods. That's the setup, here's the problem. It's has great oil pressure at startup but falls dramatically after warmup. It will go below 5 lbs if I let it, but I've never let it. I haven't driven this car this way (for obvious reasons). I have tried several oil pumps from a standard to a high pressure, high volume with the same results. Over the weekend, I pulled it apart to see what's going on. Everything looks pretty decent. The bearings were wore a little more then I thought they should be, which I figure is from the low oil pressure. Also, there was more material in the pan then I expected. Everything else just looked pretty darn good. I'm lost here - any ideas?
i know it may be a far out chance but maybe the problem is bad oil pressure gauge , but i donno youve changed the oil pump couple times and still does it , thats weird eddie
I have tried multiple oil pressure gauges - that's the first thing I tried. I was hoping that was the problem so I wouldn't have to pull the motor again. But, even with a gauge that I KNOW works (came out of another car), it still does it. Plus after pulling it apart and seeing the bearings and pan I know there's a bigger problem. Thanks for the idea.
Oil pressure issue Check the front of the Block - Make SURE all the plugs to the oil Galleys are still in place. You might be able to shine a light down the distrbutor hole and / or use a mirror to see. If one has popped out or is missing - it will cause minimal oil pressure - could be your problem. Also check the oil pump shaft at the bottom of the distributor - make sure it is engaging and turning the pump - could have rounded out the drive opening on the pump. It`s also possible that you have a weak spring in the oil pump and it is bypassing prematurely. Good Luck.
I checked the oil galley plugs over the weekend and have double checked the oil pump driveshaft and the new pumps I used. They're fine. Thanks!
hmm this is becoming interesting, have you checked the pick up , might be something in there , might have cloged, i m not sure just throwing ideas out there eddie
I have tried two pickups. Now you see why this is baffling me. I just talked to my machine guy...I'm running by after work with the block, crank, and cam to see if he has any ideas too.
Yes, I even tried a different weight of oil to see if it would make ANY difference at all. No luck. Yeah, this is what I was thinking - that's why I'm going by the machine shop on the way home.
I Am Experiancing A Simular Problem So I Am Eager To See The Outcome Of This Thread As Well. The Engine I Put Together Is Simular To Rando's And I Am Having The Same Problem But Now, As I Have Put Some Miles On The Engine, I Have A Slight 'rod' Knock At Higher Rpm's..... So Im Thinking It Has To Do With Rod Bearing Clearence Issues. Who Knows..
It sounds like you had enough oil pressure that you could drive it! Mine will fall below 5 lbs after just a few mins of idle. But at startup, it's probably 60 -70 lbs.
Upon Start-up, Mine Was Right Above 60 Lbs. With A Melling Hv, Once Warm It Fell To About 16-20 At Idle.... And The More Miles I Put On It, The Oil Pressure Lowered Slightly. It Still Has About 14 Lbs At Idle Right Now But If U Rev It Up, You'll Hear Something Very Unpleasant I Run Std/std Bearing In Mine And I Think I Should Have Went With .001 Oversize. Im Ordering Some .001 Oversized Ones This Week And Im Gonna Attempt To Put The New Bearings In W/O Engine Removal...lol, Wish Me Luck
