Getting the Proper Oil Pressure on a GSX1300 Dragbike Engine

Challenge : One of our customers needed to obtain the correct oil pressure reading for his screamingly fast GSX1300 dragbike. In particular, he needed an accurate reading for the highly customized and tuned engine's connecting rods to make sure they were correctly lubricated during its very brief, but highly punishing runs.

The typical approach has been to tap into the hydraulic cam chain tensioner lubrication point. However, after some study, we determined that the oil pressure here is bled down by the oil feed to the transmission and heads. Thus the reading would not be sufficiently accurate for this application.

An alternative was to tap into the bottom access hole closer to the connecting rods. Unfortunately, this machine's particular configuration would force electrical wiring into its sidewinder exhaust. Now we could try calling all of the hydraulics distributers we know, explaining that we have an 18.0 X 1.5 mm access hole and need a 90 degree angle to a 1/8 NPT standard thread; all within an overall length of 50mm. But, basically that option was out of the question as no one was going to have those parts lying in inventory.

Now you could say, I have too much machining tools on hand, but I prefer to view my equipment and knowledge of how to design and create with them as allowing me to formulate options where none existed. In this instance, I added some billet alloy and made the necessary part. Here's a few photos to show how it went.

Starting with the proper billet.

The base piece is taking form with 18.0 X 1.5 mm threads.

Note the oil channel machined into the center. The part on the right is an AEM oil pressure sensor.

Now we add the 90 degree 1/8 NPT standard thread tap. Note the flat areas on the end. These are added so that an open-ended wrench can be used to tighten the piece into the engine's 18.0 X 1.5 mm access hole.

Now this is taking shape!

A test fitting between the oil pressure sensor and the 90 degree oil channel. This looks ready to go!

Ah! In place on the engine. No interference between the exhaust and the pressure sensor's electrical leads.

Hope you enjoyed this little article on how we at Metric Motorcycles create custom solutions for custom challenges. Thank you for your interest in our work and thank you to all of our customers for your business!

Andy Marcer