With more and more vehicles getting an engine of LS origins swapped in, we have put together a guide that shows how to get both your oil pressure and water temperature measurements using AutoMeter adapters.
Due to the metric ports on the LS based motors, a standard 1/8″ NPT sender won’t bolt on directly. Fortunately, AutoMeter makes a number of adapters to make this process easy.
The first way to get an oil pressure reading is to use the factory port on the back of the engine. This is an M16x1.5 thread. AutoMeter Adapter #2268 will thread right in place and give you a proper 1/8″ NPT port.
Here’s a shot of the #2268 adapter being installed (prior to being fully tightened) with its included sealing ring.
Here, you can see a Short Sweep Electric Gauge Sending Unit installed (Part #2242). The 2242 is included with the short sweep gauges. In cases where space is at a premium, you can also run a piece of braided hose to the sender to get it up off the block. There is no reduction of accuracy or function to remote mounting the sender and oftentimes, the reduced vibration load can increase the overall lifespan of the unit.
The solid state, full sweep electric senders are much smaller and typically don’t require relocation. These also deal with vibration a little better than the larger short sweep senders (Part #2246). This is included with the Auto Meter full sweep gauges.
On the back of the passenger’s side cylinder head, there is an M12x1.5 port. Due to the small size of this port, you will not be able to use a mechanical temp gauge without drilling and tapping the head. An electric gauge is definitely the way to go here.
AutoMeter Adapter #2277 threads right into place here to get you a proper 1/8″ NPT port.
Again, because of the small size of the port, a standard Short Sweep Electric Temperature Sender will not fit. You can use AutoMeter Replacement Sender (Part #2259) and it will clear perfectly. Accuracy is not affected by the lower profile.
Here is a picture of a #2259 Short Sweep Electric Temperature Sender installed in the head.
Due to its thinner profile, the sending unit from the full sweep electric gauges threads right in.
Another option for oil pressure is to remove the cover plate right above the oil filter and then drill and tap it. This a great spot on the engine to get a really precise oil pressure reading.
Here is a picture of the cover removed from the engine. It’s just two bolts, and the gasket is reusable.
In order to properly tap the unit (NPT threads are tapered), we remove a little bit of material from the protruding neck.
Here, we drill through the blind hole of the cover plate with a 5/16” drill bit.
Then, it is chased with a 1/8″ NPT pipe tap. We recommend not going further than half way with the tap, then check fitment of the sender as these are tapered threads. You do not want the sender to bottom out. The sender should thread in, leaving a couple of threads left over as it tightens up, being that the threads do the sealing.
Here is the finished product.
Now our sender screws right into place. If you still have the stock exhaust manifolds on the engine, clearance can be a problem and the unit will probably need to be remotely mounted. However, most aftermarket headers provide plenty of space.
Here is the smaller Full Sweep Electric Pressure Sender installed in our new port.