I've got a 72 chevelle with a 454. I rebuilt the motor while it was in the body shop. I had the motor bored out .030, due to wear. I had the original crank checked and had the journals taken down about .010. I had the rotating assembly balanced. I installed new bearings, oil pump, eagle stamped rods, KB pistons, and high volume oil pump. From the time I started up the engine, I've had a valve tap. (never let a friend talk you into letting them do the valve work). The oil pressure starts out at 60psi till the engine gets hot, then its always run at 20 psi in gear at a stand still until recently. Now its at 9 or 10 psi and it sounds like the valves are comming out, but i cant tell if its from the bottom end. Do you think its an oil return problem or bearing problem ( rod or crank) ?

Mike, Does the oil pressure come up to a respectable # at higher rpms? Does it still read 60 psi with a cold engine? I wouldnt think it is a return problem, that would show up at higher rpms instead of at idle.How many miles on your rebuild? 10 psi does sound low at idle. As for your noise, is it there with a cold engine and higher oil pressure or only after it warms up? Does it only make noise at idle or at all rpms? Maybe a bearing problem. If you bring the rpms ,and oil pressure up and then let off of the throttle does the oil pressure jump up slightly when you let off? If it does that indicates worn main bearings, rod bearings will make a rapping type noise on accel. just a few thoughts.Maybe they help maybe not...lol Steve

Mike,

It sounds like you could be having the onset of some type of bearing failure. Before you do anything drastic, drain some of your crankcase oil out and save it for an oil sample analysis. Look in the phone book, but there are usually several companies that can do this for you at a small cost. They can till you real quick if your having bearing failure. Most large truck fleets use this service to monitor their engines for early failure wear and tear type stuff before it sidelines their rig. Over the road repairs are not cheap. Anyway the oil analysis could give you some extra insight as to whats going on in your case.

Steve, yes the oil pressure comes up to 40# at speed. It does read 60# with cold engine. The engine has about 1500 miles on rebuild. The engine noise is only there when engine is hot, and at idle. If I shut down engine for 10 - 15 min., the sound goes away till engine is hot again. Oil pressure on restart is 20#, then drops off to 10# after running for a short time. If I rev the engine, noise goes away. As I said, it's always had valve chatter. I replaced the cam and lifters twice, but he other noise seems to be a deeper sound. Also, I've been running 10w30. Its been suggested to me that I run 50 weight oil. I'm in Ft. Lauderdale, and the temp. rarely gets into the 40's, and thats only in the middle of the night, and for only a few weeks a year. What do you think about 50 weight oil?
Steve, thats a great idea about oil sample. Thanks.

Mike, Thanks for the compliment on the oil analysis,however that was Rich Tills idea..lol.. I realy dont believe that your oil viscosity is the problem. 10w30 should provide plenty of lube if your bearing clearences are ok. Many new vehicles run 5w20 with no problem. Its odd that with a warmed up engine if you let is sit for 10 or 15 min. that you see that your oil pressure doubles for a short time. Your engine shouldnt have cooled off too much in that short amount of time? Why have you changed your cam and lifters twice? You have changed the oil and filter along the way somewhere havent you? Is it possible that your filter maybe plugging up? The lifter noise going away at higher rpms may just be related to the increase in pressure. The other noise is it more noticable in gear under load or not? Just a few more thought to ponder...Steve

did you have lobe failures that caused you to change the cam and lifters twice?

if so, did you pull the engine and clean the junk out of it?

Steve and Tom, I changed the cam and lifters twice believing this may get rid of the valve tap. I think the new valve seats were not ground properly to fit new valves. As far as oil changes go, I change my oil about 4 times a year due to very high humidity levels in South Fla. R/H normally runs about 90 to 95% in the summer months. I do notice white gunk in valve cover breathers. I have never found any in oil. I've inspected oil after each change. Also, no signs of it under the valve cover. I just think thats its moisture from high R/H. The other noise goes away under load. The valve noise is pretty constant, just increases with rpm.

Quick update. Did oil change. Installed new KM oil filter and new oil. Oil at 70# at idle cold, 85# st 3000rpm, and engine knock at all rpm. Going to pull engine next week and check bearings. Will post results. Thanks for all input.

You had a Fram on there before, didn't you?

Mike, Did you try the w50 oil and this is the result? I think pulling the engine and checking the bearings is a good idea! One tip, when you pull the engine, remove the oil pan before you tip the engine over. Helps keep any debris from falling back into the engine if there is any. Im not sure what the Fram comment was all about...Personaly I use Motorcraft filters..Please let us know what you find...I hate it when I try to help and then never find out what the results were..lol Steve

Steve, yes it was with 50W Lucas oil. I didn't use a Fram oil filter, I used a K&N oil filter. I could hear what sounded like a rod knock on start up of engine. This time, it was with a cold motor it was knocking, even with 70# of oil pressure. When I reved up motor to 3000rpm, I could no longer hear it from inside the car, however, my friends could hear it out side of the car. I will be pulling the motor next week. I have the cherry picker, but loaned out my engine stand. Once I pull it apart, I'll repost what I find. Thanks for the help.

have you found anything out yet. my motor is making a sound and my pressure is 18 at hot idle, 60 going down the road.