Engine is brand new 2.3 liter stroker that runs great except no oil pressure in the first 8 seconds then it runs fine with 30 lbs at idle and 60 lbs at highway speeds. Temp runs at 180 degrees normally with 210 being the hottest on very hot days. Any ideas on why it takes 8 seconds? Validated on dashboard guages and a mechanical guage. I can't drive this until I get pressure with the turn of the key.

I see my mechanical gauge showing pressure right after the engine starts. 60 psi is great. I would attach a gauge at the engine and have someone start the car to see if you have instant pressure. If so you have a delay of oil pressure reaching the gauge.

External oil coolers / non OEM plumbing?

Are you running an external oil cooler?

That’s my guess

Oil is having to pump to the front before returning to the motor



Accusump for pre oiling might be one solution

Something about a mechanical gauge, I have one for sure. Cheap insurance

Agree with the sentiment/concern in some of the other questions, that something external like a cooler or filter could be causing drain-back when the engine isn't running.

This is worth validating - 8 seconds to generate oil pressure after startup is too long.

Do you have a high-mounted remote cooler or filter by chance? Gravity could be your enemy here.

Edit - you could check for presence of oil in any external oil circuit before startup by disconnecting oil lines.

Thanks for the info. There is a front end oil cooler and gravity could be my enemy. I think adding Accusump might be the answer. I'll let you know how it turns out. This is a 914 after all. Oil pressue is 30 lbs at idle until the engine gets hot then it drops and adding some rpm's fixes that. With good rpm's at road speed it will stay around 60 lbs. I haven't put it on a dyno yet but my guess is about 150 HP.

If you route the oil lines with a high point near the engine you won’t get the drain back, but you will need to open the lines to do oil changes. Or you could add a drain valve at the low point.

I BELIEVE in Accusumps.

I think they should be a part of every serious build.

I ALSO believe in the electronic remote shut off valve.

Jump in the car, hit the Accusump release and see oil pressure BEFORE the crank moves.

You betcha!


Having said that...

I think you have an actual problem that needs to be diagnosed FIRST.

From what I understand the T4 does not operate like a 911 six in that ALL of the oil goes through the pressure side of the pump before it feeds the cooler and the cooler returns it to the oil galleys.

Normal wet sump operation with the addition of 16+ feet of hose and the front oil cooler.

This system SHOULD NOT drain rapidly when turned off. The pump itself closes one end off and the engine oil clearances close the other end.

Does your build include 911 style piston squirters?
Those might create a drain path.

Do you have an oil thermostat?
If this will be used on the street you should.

Either way I'd try removing the oil cooler (looping line on engine) and see if that made a difference.

I'd check my oil level directly after a fully heated up drive and then recheck it 12 hours later.
Did it go up much?

I think you have a minor leak on the suction side of the system (internal in the engine) and the pump/pickup tube drains overnight.
Even this really shouldn't need 8 seconds to prime.

Excessive bearing clearance might be a culprit, but it would have to be BAD.

On installing the Accusump.

I'd want it feeding the engine as far from the oil cooler return as possible.
A big Accusump is 2 quarts and I'm betting your oil cooler and lines are more than 2 quarts.

I'd want my Accusump feeding the engine and not the cooler...

One thing that came up during my research into T4 mods/improvements.
The oil pumps suck big balls...
There can be a serious difference in pump quality and diameter between all of the different variants. It's EASY to end up with an internal leak between the case and pump that you cannot see/diagnosis easily.
Some pumps come with recessed O-rings specifically for this purpose.

The oil pump looked like it required extra care in selection and application to me.

 
I'm interested in how this progresses.

@technicalninja

There is no such problem with the OEM T4 pump.

The problem is people keep insisting on using the T1 pump in a T4 engine.

The only disadvantage of the T4 pump is the tendency of the idler shaft to migrate toward the cam gear when the engine has been abused and overheated. This can easily be addressed by pinning the idler shaft.

There shouldn't be any oil going to the cooler unless the oil is hot. Sounds like your bypass valve is bad or someone forgot something in the build.