440 Charger
Well-Known Member
I just want 75 at idle.
No oil pressure on new 426 Hemi build
- Thread starter 69 hemibee
- Start date
What’s up dock
Well-Known Member
I've seen the same thing happen with a stuck pressure relief valve in the oil pump. Oil would flow, but would not come out of the oil pressure port on the back of the block. Basically, you have flow, but no pressure. The relief valve is an easy check, since the pump is external. Just remove the large nut, then the spring, then the valve is behind that. It should move freely. I always take new pumps apart, clean, polish the valve, sometimes honing the bore if it's too tight. Assembly lube all parts before re-assembly.
This would have been one of the things to check BEFORE running the engine.
This would have been one of the things to check BEFORE running the engine.
69 hemibee
Well-Known Member
This was my first thought as well and the reason I changed the oil pump. However after installing a new pump the problem still exist. Here are a few pictures of the old relief valve.
What’s up dock
Well-Known Member
I did go measure a few blocks just now, thinking of the depth measurement you gave. Just approximately, I get 3.80 inches. That would be from the outside edge to the bottom of the lifter oiling bore.
The other thing I've seen is there are many different types of pipe plugs, some shallow, some deep. Some of those shallow ones can be screwed in so far, counter sunk into the block, and would block that port leading to the oil gauge. Unfortunately, that doesn't jive with the depth you are getting. If it was blocked with the pipe plug, you would have less depth.
Was that a new block, or an old block? The reason I ask, is there used to be a kit for blocking oil to the solid lifters, using only the valley oil and splash from the crank. If it was a old block, that could be the case if prepped for race back in the day.
Sorry, I'm just brain storming for you.
The other thing I've seen is there are many different types of pipe plugs, some shallow, some deep. Some of those shallow ones can be screwed in so far, counter sunk into the block, and would block that port leading to the oil gauge. Unfortunately, that doesn't jive with the depth you are getting. If it was blocked with the pipe plug, you would have less depth.
Was that a new block, or an old block? The reason I ask, is there used to be a kit for blocking oil to the solid lifters, using only the valley oil and splash from the crank. If it was a old block, that could be the case if prepped for race back in the day.
Sorry, I'm just brain storming for you.
69 hemibee
Well-Known Member
Appreciate the brainstorming, the measure I had included the fitting so if you took that off I'm close to 4", which seems normal based upon your measurements. The block is a 67 block, so nothing crazy. If they did race prep it like you mentioned I would think you'd still need a positive indication of oil or some way to gauge pressure. How did the racers do that?
I haven't had a chance to use the other port as someone mentioned as I've been busy working on the kids car but I'm planning to this wknd.
440 Charger
Well-Known Member
2 psi would be very bad.
69 hemibee
Well-Known Member
Good point, but I made sure the gasket it on the engine side
440 Charger
Well-Known Member
Well I am getting 60
440 Charger
Well-Known Member
So think this way is good for these old motors.
69 hemibee
Well-Known Member
Good news! After taking a few months off, retiring from one job and starting a new career, buying a house, holidays, and whatnot I decided to dig into oil pressure problems on the superbee. Tore apart the front end of the hemi after I had a hunch that an internal oil galley plug was missing and creating a massive internal leak, causing me not to get oil pressure. Well...sure enough a plug was missing, just not the one I thought. @Fran Blacker called it.
I thought it would be the plug facing the ground as its easily missed but it was the one behind the timing chain. I should have caught it when I assembled the motor long block and that one is on me. So happy it's a cheap fix instead of a complete rebuild. Now we wait for the plugs to arrive next week.
I thought it would be the plug facing the ground as its easily missed but it was the one behind the timing chain. I should have caught it when I assembled the motor long block and that one is on me. So happy it's a cheap fix instead of a complete rebuild. Now we wait for the plugs to arrive next week.
Post#2 your welcome. 
Glad you found it. I thought it would have been the other plug.
Glad you found it. I thought it would have been the other plug.
69 hemibee
Well-Known Member
Me too bud, me too. Either way glad it was just a plugPost#2 your welcome.
There were many good suggestions to follow before ripping into the engine.
Runcharger
Well-Known Member
Carefully check the camshaft and lifters, I would also pull a few bearing caps to make sure nothing is hurt. If something is hurt it will cost you a little bit now to repair it, or a lot later.
This is why you had flow to the top with no pressure. Under static conditions the pump had enough oil to get oil to the top. But nut enough pressure with that flow to move the gauge. The volume of flow wouldn't have sustained a hydro dynamic wedge while running. How long did it run like this? There may be damage
25 mins with minimal oil it is a looong time. I'd pull some caps rod and mains. As Runcharger said cam and lifters. Better find out now for peace of mind. Bad things happen fast and get more expensive.
Fixed it for you...
Similar threads
