Mechanical oil pressure gauge hook up?

[titaniumdave]

I have some questions about hooking up a mechanical oil pressure gauge. After having the reading fluxuate at constant RPM, I want to know what the oil pressure is really doing. I have mounted an Autometer gauge to the deck above the engine, I can easiy read it in the rear view mirror. I have installed a 'T' fitting between the electric oil sensor and the front head, the plactic oil line is hooked in the 'T' before the electric sensor. I get a reading off of the electric sensor(gauge in the dash) but I get no reading from the mechanical gauge. When I unhook the line to the mechanical gauge at the gauge, oil drips out, there seems to be no pressure. I have checked the line and I can blow through all the way to the 'T' fitting, and the fitting is clear.

Any ideas what I did wrong? Is there something that looks like an oil sensor but isn't that I am hooked into?

Ideas?

 

[Briank]

I bet you tapped into the spool valve pressure switch. Connected there you will not see any oil pressure until about 5000 rpm.

See

http://www.nsxprime.com/FAQ/Reference/1991_svcman/1991servman.pdf

Page 92 of the pdf file shows where to connect

 

[titaniumdave]

Damn, I think you are right! I will check tomorrow when I have some light.

Thanks for getting back quickly, before I pulled out all my hair!

 

[titaniumdave]

Gauge hook up

Ah, yes. Should have asked before I started messing around. I was on the spool valve, it sits just above the oil pressure switch. I could not figure a way to 'T' in between the block which the oil pressure switch screws in and the switch, there is no clearance above the switch. I decided to drill and tap the block which the switch screws into. I drilled a hole in line with the oil feed from the block, perpendicular from the hole the switch screws into. I tapped the hole 1/8" pipe thread, screwed in a 90 degree elbow for the 1/8" line to connect with the gauge. Leak checked it and took the whole set up for a madien voyage!

I am amazed at how much the pressure changes, holds rock solid at 75 PSI cruising on the highway, 2.5-4K. As I accelerate, pressure rises to 85 PSI at 5.8K, as soon as the VTEC kicks in the pressure drops to 75 PSI and hold there all the way up to 8K. I have found pressure as high as 95 PSI if I accelerate moderatly through 5.5K RPM. The dash gauge seems to float just below 6 bar most of the time except at idle, when it drops to just above 1 bar. The mechanical gauge indicates 25 PSI at 800 RPM idle.

Seems like some nice peace of mind to have a double check on the pressure, I will be interested how things look at the track next season when I get to run the NSX hard for a whole session.