Thread: 454 oil pressure problem

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I recently purchase a 1 ton dulley that had a bad cam. Removed heads and had valve job and replaced three bent valves and bad exhaust guides, installed new cam lifters and timing chain. Started truck to break in cam ran good for about 3 minutes with 60 psi oil pressure. Oil pressure started vibrating between 30 to 60 then went to 0 I shut the engine off. Talked to several people the consensus is I have a spun rod bearing and that starved the cam of oil causing the cam failure. Before I pull the engine does anyone have any other ideas?

Nope, tear it down and see what you can find out.

I had that exact problem on my 331 Ford. Found out I blew out a galley plug so oil was just dumping out into the timing chain area instead of going through the paths it was supposed to take. Not saying that is your problem, just a suggestion. You might have also spun the driveshaft to the oil pump. Pull the distributor and see what it looks like, and maybe put a preluber on it to see what you get.

Don

A spun rod bearing won't cause a total oil pressure loss, nor cam damage either. A main bearing turning might cut oil off to the cam bearings, but it would run for a long time before the cam went away, the bottom end would be wiped out long before the cam. And you would have no pressure immediately on start after changing the top end stuff.
If I had to guess just by what you wrote, I would go with the pump drive.

Years ago I had that happen on the 302 I was running at the time in my 27. Pulled out from a traffic light and started hearing ticking. Thought I blew a header gasket, but when I looked at the oil pressure gauge it was on zero. Pulled the distributor and the end of the pump driveshaft was rounded off instead of hex shaped. Put a new driveshaft in it and drove it for another few years with no problems.

Don

oil pump drives really do not fail on bbc like fords look at a busted oil pump they can fail by bolt hole mount or the pickup fell off and the rest follwed. could be many things

Just curious, when you changed the oil, ( You did do this right?). Did it have any leftover grit from the dead cam? Any glitter? Oil pump screen may be clogged up from trash in oil pan, If thats the case the pump is a dead player too... Consensus of Rod bearing?? Did it knock??
I say drain the oil again, look at it closely and if you can, cut open the oil filter, If there is more grit in there then It.s gonna need at least the pan off for a closer look. Good Luck, I always have that same thing happen to me on my "good deals that I cant say no too" Good Luck keep us posted...

Thanks for all the input, I tried all of the sugestions but no help. Engine is at the machine shop and I should have the answer by next week. I will post the findings so maybe it can help someone else. I guess there is no such thing as a good deal.

Heard back from the machine shop and the problem was a presure valve and spring that had come apart in the oil pump. The bearings were all overheated but none had spun. Doing a complete rebuild .30 over with new pistons and crank. I bought a Eagle crank cheaper than it would be to ship mine to Phoenix to be turned
.10/.10 and shipped back, go figure. I should have a good running engine now hope to have it installed in two weeks.