New Dry Sump Setup - No oil pressure

[type1.racer]

Looking for some help. Have a new build (was actually built a long time ago, just sat in the garage) with a dry sump setup. Before initial startup I always like to ensure the motor has oil pressure. I pull the plugs and rockers, let the starter do its thing. Usually do about 20 second intervals pausing every 30 or so. Typically after 2-3 mins I see pressure.

With this dry sump setup (CB pump), i'm not getting any pressure reading on my gauge. Hoping someone can help out. Here is the flow:

Driver side pump -> oil filter -> thermostat -> oil tank -> passenger side pump
thermostat has another in/out connected to the oil cooler. I believe it sends ~ 15% of oil at all times down that path

I've taken off the line at each point and cranked over. I can confirm oil is making its way down the paths. I've watched the level in the tank drop but never go empty, same for the oil in the case (via dip stick). My sender is located in the fender with a -6an line going from the stock dummy light location over to my sender. Pulling the line off the sender and cranking, oil is spilling out.

Based on the above, I know oil is circulating. There is always the potential that my sender is bad but I had another motor in the car not long ago and it worked fine, setup the same way (full flow, not DS but same oil line routing). This is a dual relief case, new CB pistons/springs. I pulled the plug on the flywheel end and cranked over, oil came spilling out the hole. So it seems like there "shouldn't" be any blockage. This leaves me with a few concerns:

1. Is the pump not strong enough given the -12 lines + length
2. Is there just not enough RPM from the starter to see the pressure (battery is fully charged)

Curious what other people have done or seen. I'm tempted to just fire the motor as I know I've got circulation but also afraid of locking it up

[Ol'fogasaurus]

Got a pix pf the oil pressure sender and how it is mounted on the block?

Lee

[type1.racer]

Got a pix pf the oil pressure sender and how it is mounted on the block?

Lee

20220110_115856.jpg

[Ol'fogasaurus]

The reason I asked the question was that some of the dual function oil pressure senders (idiot light and oil pressure gauge) can be located with the reservoir facing up or down which can cause problems similar to what you are having. I had a similar problem myself, so I removed it and went another direction.

The answer I was given was to have the domed area facing down so oil could stay in there and the area did not have to be re-filled all the time.

Lee

[type1.racer]

The reason I asked the question was that some of the dual function oil pressure senders (idiot light and oil pressure gauge) can be located with the reservoir facing up or down which can cause problems similar to what you are having. I had a similar problem myself, so I removed it and went another direction.

The answer I was given was to have the domed area facing down so oil could stay in there and the area did not have to be re-filled all the time.

Lee

Interesting theory, my only hang up with it is the location, positioning, even the line hasn't change and all that worked with the motor I had pulled out.

[Ol'fogasaurus]

Interesting. The 1776 I have now has had the block converted to a "full flow" oil system (no good pix on this).

The oil pressure problem I had was again, the "domed area" facing "up" rather than "down" so oil would stay in the reservoir.

Your system doesn't look like mine so start with. I wish I could help more.

Lee

[Bruce.m]

Disconnect the sensor & see if oil squirts out on crank. Probably an air pocket next to sensor

[type1.racer]

Just to follow up on this in case anyone comes across it in the future; I ended up taking quite a bit apart and troubleshooting. After finding nothing wrong, I ended up just starting the motor. I knew oil was circulating correctly so it wouldn't be a completely "dry" run. The moment it fired, oil pressure instantly went to 50psi.

I've got another issue now that its running, but i'll save that for another thread.

[Ol'fogasaurus]

I wonder if you had an "air pocket" in the system.

Not an unusual thing to hear about, sometimes just taking things apart then reassembling it can get rid of the problem. Also, I usually prefill my oil filter also before starting a filtered-up rig for the first time.

Good to hear things are OK now.

Lee