1970455sx

ok so i have a rebuilt 70 455 engine while priming the motor i was only getting 10 psi and noticed that two of my lifters were not getting any oil... i pulled them out and seen that the oil passage right below the lifters were pluged up with dirt or something. could this be the reason why there is no pressure? oil pump is good tested it..... or could it be the main berring clearence or oil filter (new filter though)also new oil pressure guage. any ideas?

MDchanic

Okay, oil passages "pluged up with dirt or something" would imply that when this engine was "rebuilt," the oil galleries weren't scrubbed with a long, narrow "bottle brush" and blown out thoroughly with water and / or compressed air.

If this is the case, then all bets are off, you've probably got a gallery clogged somewhere by something, and everything's got to be scrubbed and blown through before you try to go any further.

Good that you tried to prime it properly, rather than starting it right up, like some people would.

- Eric

Rickman48

If you had the motor rebuilt by a company, call them and explain the problem!
Sounds like the motor wasn't cleaned properly, and there's still dirt in the oil passages!
When rebuilding a motor, we always used a 'rifle' brush on the oil gallerys - that's what the plugs on the back of the motor are for.
Hot tanked before machining, soap and water and WD-40 before assembly!
I'd not run a motor on 10psi for a minute!
10 PSI per 1000 RPM with idle @ 30 PSI should be a minimum! = 80lbs @ 5000 RPM
Pull it out and find the real problem!!
Is the oil pump pickup at the correct position?? 1/2 inch from the bottom of pan??
And tack-welded?? [very common problem!]
Good luck!!

1970455sx

ok it does look like it could be really clogged. iam gonna try to clean it first then try to check the pressure again..... also the oil pick up is set perfect 1/2 from bottom. I was at 10 psi.... so i should be looking for at least 30 psi when priming?

Texas Jim

whoever did the vating and cleaning should be kicked in the seat of their pants. Unless it wasn't a shop and you did it just w/ what you had. But like these guys said, take it down and clean it right, essential to keep things from killing the engine prior to it ever getting on the road. You did right, seeing that priming wasn't getting the correct results. Priming will make or break the engine. I couldn't imagine not priming an engine prior to starting it. The old saying in the old machine shops: "If you don't have the money and/or time to do it right the first time, where will you get the money and/or the time to do it right the second time?" I don't mind pulling out onto the street and letting it rip real good w/a project that took me a long time to complete. Much better that than getting one together over-night, pulling it out on the street to let it rip and the engine shutting down on you for some internal reason. When you see something that's been done correctly, how long it took isn't usually a negative side of the conversation. Take your time, get it right.

Nilsson

If it were mine I would be taking it down and going through it.

1970455sx

ok got it.... i cleaned the motor and a bunch of crap came out.... and now the motor is at 50 psi. i think it is time to see how the motor feels on the road.

MDchanic

You took it all apart, so that you could clear out all the passages from one end to the other, right? If there's a piece of crud that blocks the passage to a single bearing, that bearing'll be toast in a minute.

Rickman48

Don't forget 20 min. @ 2000 rpm to break-in the cam!!
I'd be changing the oil + filter after that, before hitting the road, and doing ALL the break-in procedures!