Fuel Pressure Gauge

[Houle #382]

Looking to buy a new Fuel pressure gauge, which is the most accurate a liquid filled gauge or a non liquid filled gauge and what brand is a good one

 

[dvw]

Non liquid. The liquid gauge in my experience showed lower pressure the hotter the temp. I finally drained the liquid out of it. Stays constant now. It is an Autometer.

Doug

 

[Aron Gleason]

My autometer fuel pressure gauge has been very consistent for the last 25 years. Non liquid filled.

 

[RJRENTON]

Looking to buy a new Fuel pressure gauge, which is the most accurate a liquid filled gauge or a non liquid filled gauge and what brand is a good one

The liquid filled gauge (usually glycerin) slows the response time slightly. The most important consideration is: DOES THE GAUGE HAVE A FLOW LIMITING DEVICE INSTALLED INTERNALLY? Standard fuel pumps are positive displacement devices and produce a pulsed output and subject the gauge's internal bourdon tube (pressure measuring componrnt) to these pulsations and therefore subject to fatigue failure. IF...during high RPM operation at maximum flow and pressure the gauge's bourdon tube ruptures, due to the pressure pulsations AND the gauge is under hood mounted, fuel will spray every way over a hot engine....resulting in a huge fire. THIS IS WHY A FUEL PRESSURE GAUGE SHOULD NEVER BE PERMANENTLY CONNECTED ....AND THEN ONLY THRU A GAUGE ISOLATION DEVICE. If the gauge is underhood how do you read it anyway?....especially during competition endeavours??......just my opinion of course....
BOB RENTON

 

[moparsaver]

If the gauge is underhood how do you read it anyway?....especially during competition endeavours??

 

[RR Fan Dan]

The liquid filled gauge (usually glycerin) slows the response time slightly. The most important consideration is: DOES THE GAUGE HAVE A FLOW LIMITING DEVICE INSTALLED INTERNALLY? Standard fuel pumps are positive displacement devices and produce a pulsed output and subject the gauge's internal bourdon tube (pressure measuring componrnt) to these pulsations and therefore subject to fatigue failure. IF...during high RPM operation at maximum flow and pressure the gauge's bourdon tube ruptures, due to the pressure pulsations AND the gauge is under hood mounted, fuel will spray every way over a hot engine....resulting in a huge fire. THIS IS WHY A FUEL PRESSURE GAUGE SHOULD NEVER BE PERMANENTLY CONNECTED ....AND THEN ONLY THRU A GAUGE ISOLATION DEVICE. If the gauge is underhood how do you read it anyway?....especially during competition endeavours??......just my opinion of course....
BOB RENTON

Good advice. I’ve always run them and now thinking about it you’re correct. Why risk the fire. I was going to install one on my newly acquired road runner, but you changed my mind. It never gets looked at unless you have a fuel pressure regulator and are adjusting fuel pressure, which setting the fuel pressure is like using a RonCo Chicken Rotisserie, “set it and forget it”.