• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

No oil pressure on new 426 Hemi build

69 hemibee

Well-Known Member
Local time
9:00 PM
Joined
May 7, 2018
Messages
223
Reaction score
141
Location
Fort Walton Beach
Long story but figured somebody can help.

The engine is 426 stock build minus cam. Somebody else built the short block (he passed away earlier his yr) I inspected it and it looked good so I finished the rest of the build. Primed it w/drill CCW but no oil pressure via mechanical gauge. Inspected the heads and all rocker shafts and all are oiling. Put engine back together and installed it in the car to break in FT cam but still no oil pressure.

However, when priming the system I can see oil moving by looking into the distributor hole w/drill running. So I pressed w/cam break in (25 mins) because I know it's oiling. Break-in was fine, the engine purred, valvetrain was very quiet but still no oil pressure. Changed oil pump and still no oil pressure even w/mechanical gauge on back of block. Disconnect the copper line and its dry. I took a piece of wire to see if there is any blockage when the sensing unit goes and the wires goes down 4 1/2" and stops....that depth normal? Why is the oil not coming up to the sending unit location? I fired it up today to let it run, no issues, pulled pass side valve cover and it has oil everywhere, another indication of positive oiling. What am I missing?
 
Bet somebody didn't put the one of the 2 plugs behind timing chain by the cam. you need to remove upper gear to see it.
 
Last edited:
So you broke in a fresh Hemi with no oil pressure? Brave man.
 
Well if you're seeing oil everywhere, and it didn't seize during the break-in...it's oiling.
Did you try two different gauges? If so then maybe that test port isn't open (for whatever reason).
Try this:
Leave the port open and crank the engine a few times, coil disconnected (or put the drill primer to it again). See if oil squirts out...that will help narrow it down.
 
Well if you're seeing oil everywhere, and it didn't seize during the break-in...it's oiling.
Did you try two different gauges? If so then maybe that test port isn't open (for whatever reason).
Try this:
Leave the port open and crank the engine a few times, coil disconnected (or put the drill primer to it again). See if oil squirts out...that will help narrow it down.

I'll have to try the other port, didn't think about that. The gauge is good, used it on other builds.
 
I’m sure it’s beyond repair, I will haul it away for you at no cost….
 
Well if you're seeing oil everywhere, and it didn't seize during the break-in...it's oiling.
Did you try two different gauges? If so then maybe that test port isn't open (for whatever reason).
Try this:
Leave the port open and crank the engine a few times, coil disconnected (or put the drill primer to it again). See if oil squirts out...that will help narrow it down.
If you dont have oil it will break.
 
Rear cam bearing turned blocking the feed port to the gauge ?
 
Make sure it isn’t missing the #3 cam bearing. Ask me how I know. :D
 
Racers put freeze plug in left oil gallery to stop oil flow. Maybe somebody put one on right gallery at the end, but doubt it.
 
If you put a hose fitting where oil sending goes with a 2 foot hose and cranked engine over with coil wire off any oil there out of hose?
 
If you put a hose fitting where oil sending goes with a 2 foot hose and cranked engine over with coil wire off any oil there out of hose?
No, as I ran the engine and disconnected copper line from the back of mechanical gauge and not a drop came out while it was running.
 
I would not run an engine like that until I found out why. Unscrew what ever is in sending unit hole. Put hose fitting and hose into a jar. Disconnect coil wire and crank it over. If there is no oil should find out why. Copper line kinked? I'd go to source on the block.
 
Could be..besides taking it a part how would you know?

Take a thin rod ( clothes hanger maybe ) stick it down the port.
Spin the motor and see if you can feel the rod dragging on the cam ????


But i would NOT be running it untill i knew for sure.
As something aint right. If said bearing is spun ....that means that cam journal is running dry which will score that end of the cam.
 
How would know?
After a tear down looking for the problem! It happened to me one time. The better-half belatedly told me the o.p. gauge was showing'0'. Luckily, I survived. So did she!!! And the engine.
 
Auto Transport Service
Back
Top