Red rag in engine

motorider

Member
A year ago, I rebuilt my 304 and it ran very well until I parked it this past summer. Getting ready for a trip last week, I lost oil pressure after about a 15 min drive. I have both the original and a aftermarket pressure gage and the lifters were making some noise.

I drained the oil and noticed a small red strand come out with the oil. I then removed the pan and found the pick up screen completely blocked with red fibers, opened the oil pump and it was clean, cut open the filter there were some fibers but not enough to plug the filter, I think.

I then reassembled and had great oil pressure 40 cold, 20 hot at idle, and no lifter noise. Took it on an all day trip with good pressure readings. Then the next morning, I immediately had zero pressure. Removed the pan once more and the screen is plugged.

I still can not be believe I left a rag in the engine. After the first pan removal and cleaning, I thought that I May have left it in the pan. Now, I wonder if I left it in the valley? Or? Never the less, my question is; should I keep cleaning the screen or bite the bullet and look in the valley as well? Or should I plan on completely disassembling, cleaning, and reassembling the engine. A complete tear down is not something I am wanting to do, but will if necessary.

Thanks in advance.

Tom
 
I think you should. The likely spot for a rag to be lodged is in one or both of those ugly, jagged drain back holes that were punched out of the casting. You wouldn't want a fastener, small tool, or atmospheric shmootz to drop through those holes during the assembly process, so they get ragged up. Obviously I wasn't there to see that happen, but given the symptoms you're having now along with the evidence, I think you need to at least try and locate the source.
 
Like trever says, its most likely to be in the valley area.
But, I would pull both valve covers first.
If the head areas are clear, you can look thru the pushrod holes with a small inspection mirror to confirm rag location in the valley.
 
Yup, if you don't find that rag, you'll never have confidence in that motor. Time to start digging.
 
I will do a bit more investigation. You are all correct, I need a reliable engine and not solving the problem would cause me concern.
Thanks.
 
Some racers are so critical as to not use any rag that leaves fibers behind, those little fibers clog oil passages, let alone leave the whole rag in there. Tear it down and find the source, then clean everything, including the insides of the rocker shafts with non-lint whipping rags (like t-shirt material) and compressed air.
 
I removed the distributor and looked through a scope into half the valley and it was clean. Spent some time looking at each cam journal from below and found the culprit around the cam in two areas directly below the valley drain. It is too tight to remove without disassembly.

I agree with everybody that it needs to be fixed properly. As soon as I finish another project, I will remove the engine and clean everything without leaving any extras.

Thanks trevor, tiny, fd, and 1975 for your help. Your advise was spot on.

Tom
 
When I first saw this " thread " I thought about stacie from b.a.b.s he pull th same rag trick while doing his motor:icon_stressed:
 
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