Liquid-Filled Gauges vs. Dry Gauges, The Problem and the Solution – TB #903
Finding a fuel pressure gauge that is accurate, reliable, and affordable proves to be a surprisingly difficult job – more so than most enthusiasts realize. There are two main types of gauges on the market: liquid-filled gauges and dry gauges. A liquid-filled gauge is tougher and more durable than a dry gauge. If a dry gauge is under extended shock and vibration, its internals can get damaged and the needle falls off. The oil in a liquid-filled gauge protects its precision internals from shock and vibration, solving this issue. And there’s no arguing that a liquid-filled gauge looks like a higher quality instrument.
Unfortunately, there’s a hidden “gotcha” that users of this type of gauge experience: a reported lack of accuracy and consistency is common. In fact liquid-filled fuel pressure gauges do exhibit seemingly random pressure swings. The reason this happens is because, as the temperature under the hood heats up, the oil in the gauge heats and expands, causing the needle to move without any kind of pressure change within the system. Dry gauges, on the other hand, do not have these pressure swings that liquid-filled gauges do.
Here at Aeromotive, we are focused on eliminating fuel system compromises wherever possible, including gauge inconsistency. Our new liquid-filled gauges feature a special sealing plug that is fitted with a stainless steel pin-valve that can be pulled up slightly to equalize internal pressure and then pressed back down to re-seal. The gauge remains sealed but able to be equalized at any time, regardless of gauge temperature, immediately restoring accuracy and eliminating heat-related inconsistency.
Note: in order to use the pin-valve effectively, these new gauges require mounting so the face of the gauge is perpendicular (at a right angle to) the ground, and with the pin-valve/plug assembly on top.
Designed to the smaller, 2″ diameter size most popular with enthusiasts across the motorsports spectrum, these exciting new gauges feature a stainless steel case, polished bezel, heavy-duty brass 1/8″ NPT male connector, and are compatible with 1/8″ NPT female pressure ports found in most performance fuel pressure regulators. The white face with black numbers and hash marks is easy to read and includes the Aeromotive name and logo. Two versions are currently offered; 0-15 PSI P/N 15632 and 0-100 PSI P/N 15633, and are available now through any Aeromotive dealer or at: www.aeromotiveinc.com.