Sometimes used as simple indoor garlands, dial indicators play an important role on modified cars and even become indispensable when they are used on the circuit or intensively. Coolant and oil are the first parameters to monitor (in addition to intake pressure on supercharged engines). We, therefore, propose to discover step by step the installation of water temperature, oil and oil pressure dial indicator.
The installation of the sensors can be done in several ways
In some cases, for example, the oil temperature sensor can be plugged into the sump, usually via the drain plug (this avoids piercing the sump). This assembly has two disadvantages: on the one hand, the measured temperature is not realistic (underestimated), on the other hand, the probe can easily be torn off in case of the exit of the track (one can even lose all its oil!).
Some cars are equipped with an original oil pressure sensor. You can replace it with your pressure gauge, making sure that the signal emitted by the original sensor is not used as a tool for controlling engine operation. But the best in the field remains the sandwich plate. This simple wedge, which comes between the block and the oil filter, serves as a support for the pressure and temperature probes. This is the simplest and fastest method! This is the one we chose!
Note that the temperature sensor positioned directly at the motor output gives a faithful reading of the state of the fluid. Recent engines (80’s and up) are all equipped with several coolant temperature sensors. Generally, one of them is only used for the display located on the dashboard and is not taken into account by the computer (correction of the ignition advance and times of injection).
Like the oil pressure, if you replace the original sensor with that of your pressure gauge, you lose information on the dashboard. In the same way, as for oil, some adapters can be installed on the upper waterline and that measure the temperature of the liquid at the motor output. Check the inside diameter of your hose and make sure that it has a straight section long enough to fit the adapter.
Upstream work is needed
Before embarking on the installation of the dial indicators, you will have to carry out punctilious research work. Judicious choices, regarding both the compatibility of elements and the respect of a certain quality, you will avoid many disappointments during assembly! The biggest puzzle concerns the compatibility between the threads of the probes and those of the sandwich plate or the adapter on the water hose. Check both the diameter, but also the pitch of the nets. In many cases, the indicator is offered naked (without sensor). It is then necessary to ensure that the two elements associate without a problem. The probe is for example not always calibrated in the same way as the mano. A stupid and nasty detail: pay attention to the units of measurement (pressure in bars, the temperature in degrees Celsius, etc.)! American products, for example, do not use the metric system … Nobody is perfect. You will avoid to your brain a gymnastics of conversion of which it would be well in sports driving! Another critical point is the extension screw of the sandwich plate. On Japanese cars, there are three types: M20x1.5, M18x1.5 and 3/4 UNF-16. The first two are very similar and it is for example possible to screw an M18 bit into an M20 thread. Although the elements are assembled without a problem, the game between the nets weakens the assembly. To forbid! Finally, measure the diameter of the O-ring. The bearing perimeter on the block can be quite narrow. You will not have much room for maneuver. You will avoid to your brain a gymnastics of conversion of which it would be well in sports driving! Another critical point is the extension screw of the sandwich plate. On Japanese cars, there are three types: M20x1.5, M18x1.5 and 3/4 UNF-16. The first two are very similar and it is for example possible to screw an M18 bit into an M20 thread. Although the elements are assembled without a problem, the game between the nets weakens the assembly. To forbid! Finally, measure the diameter of the O-ring. The bearing perimeter on the block can be quite narrow. You will not have much room for maneuver. You will avoid your brain a gymnastics of conversion which would happen well in sporty driving! Another critical point is the extension screw of the sandwich plate. On Japanese cars, there are three types: M20x1.5, M18x1.5 and 3/4 UNF-16. The first two are very similar and it is for example possible to screw an M18 bit into an M20 thread. Although the elements are assembled without a problem, the game between the nets weakens the assembly. To forbid! Finally, measure the diameter of the O-ring. The bearing perimeter on the block can be quite narrow. You will not have much room for maneuver. The first two are very similar and it is for example possible to screw an M18 bit into an M20 thread. Although the elements are assembled without a problem, the game between the nets weakens the assembly. To forbid ! Finally, measure the diameter of the O-ring. The bearing perimeter on the block can be quite narrow. You will not have much room for maneuver. The first two are very similar and it is for example possible to screw an M18 bit into an M20 thread. Although the elements are assembled without problem, the game between the nets weakens the assembly. To forbid ! Finally, measure the diameter of the O-ring. The bearing perimeter on the block can be quite narrow. You will not have much room for maneuver.
The mounting of the dial indicator
Once all the elements in hand, think about making clear montages. On the oil side, check that the extension screw presses the plate correctly on the block, that the filter, too, presses the plate without any constraint and that the oil can normally circulate towards the filter (sufficient clearance between the end of the screw and the inside of the filter). A blank mount is also useful for checking the orientation of the probes. These must not be in contact with the motor. The plates sometimes have several holes, thus increasing the possibilities of assembly. Keep electrical wires away from moving parts (pulleys, belts, etc.) and avoid bending them. The temperature probe may sometimes have a long measuring tip. Be careful that its tip does not come into contact inside the sandwich plate (risk of breakage). Rest assured, mounting a sandwich plate usually happens without a hitch, provided that the preliminary work was done correctly. It is important to control everything well in order not to break his engine stupidly! Finally, think of working cleanly and handling the parts carefully to avoid getting dirt inside. Small reminder: the oil leaves the block by the periphery and returns inside by the center after being filtered. Finally, think of working cleanly and handling the parts carefully to avoid getting dirt inside. Small reminder: the oil leaves the block by the periphery and returns inside by the center after being filtered. Finally, think of working cleanly and handling the parts carefully to avoid getting dirt inside. Small reminder: the oil leaves the block by the periphery and returns inside by the center after being filtered.
Steps to setup
- Mount the car on four candles, drain the engine and remove the oil filter. Once all the oil has flowed, screw in the bleed screw.
- Prepare the sandwich plate: install the probes (and adapters if necessary). Use dough for sump (e.,g. Loctite Autojoint black) on the threads of the probes
- Cap the holes that are not used. Use sealant for corks too.
- Grease the sensor connectors (grease supplied with the indicators in our case) and connect the cables.
- Apply a little grease in several places in the O-ring grooves. This trick helps keep it in place when positioning the plate.
- Remove the thread lock (low grip, green Loctite type) inside the extension screw.
- Carefully position the sandwich plate with the extension screw. Make sure the O-ring stays in position. Orient the plate so that the probes are not in contact with the motor.
- Tighten the extension screw firmly. Attention: on some cars, the male part of the engine is fragile (SR20 in particular), do not force in this case.
- Install the new oil filter and pour the required amount of oil into the engine.
- Drain your cooling system.
- Disassemble the upper water hose.
- Cut the hose in the middle of its straightest part and remove a slice of about 2cm (depending on the shape of your “T”).
- Install the water temperature probe on the “T.” Use sealant on the net.
- Insert the two pieces of pipe on the “T” without tightening the clamps.
- Install the assembly between the engine and the radiator. Vary the orientation of the different elements if necessary. Be careful that the hoses are not bent or pinched. Tighten the collars.
- Grease the probe connector and connect the cable.
- Fill the engine with water.
- Start the engine and follow the oil and coolant return procedures (leak detection, levels, air bubbles, etc.).
Tooling
The installation of dial indicators requires many tools, most common. This includes candles, an oil tank, a jack, a coolant container, a funnel, a set of flat and cruciform screwdrivers, a socket case and ratchet, a large diameter socket for expansion screws ( size may vary), an oil filter wrench and a set of flat keys to tighten the probes. To ensure the correct assembly of some parts and a seamless seal, provide you with a tube of silicone grease, thread lock with a light grip and joint paste designed to withstand high temperatures and corrosive liquids (oil, gasoline, etc.).
Not always easy to navigate the jungle of products offered! The models we have chosen have the advantage of being supplied with their probe. The electric cables are also part of the package. The oil pressure dial indicator also receives an adapter for the probe allowing it to be mounted on any support. Thanks to their large measuring range (needle scanning of almost 300 °!), This series of Stack dial indicator finally offers an accurate reading of the measured value. Quality products, reliable and precise, for the most demanding of you!
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