Today, I did something I have been wanting to do for a while. When I bought my engine, the builder told me it had already been primed. If you have been following my build, you know that I drained all of the oil when I replaced the oil pan. I never put oil back in the engine because I wanted to ability to rotate it on the engine stand. I wasn't worried about corrosion since there was residual oil inside and my shop is climate controlled. Since I am prepping to install the engine into the frame, it makes sense to get oil back inside this thing. I figured the best way to add it was by priming it again. This way, I can see it for myself and check for leaks in the process. There are a few ways to go about priming an LS engine, even though some say you can't. I found a cool video that offered a pretty inexpensive method. Here is what I ended up doing.
I needed two of these fittings. One gets installed into the front oil port on the side of the block. The other gets installed on the top of the block where the oil pressure sensor normally lives.
Next, I needed to install a hose barb into the previously installed adapter on the side of the block.
Next, I installed an oil pressure gauge into the previously installed adapter on the top of the block.
I'll be forcing the oil inside the engine with a pump sprayer. I had to make a few modifications to it for this to work. First, I installed a metal valve stem so the bottle pressure can be measured during priming. Second, I removed the external spray tube that came with the sprayer and replaced it with 1/4" clear tubing.
The engine builder originally put 3 quarts of oil in this engine. He supplied an additional 3 quarts with the purchase. I'll be used this oil to prime. Before I start though, I filled to kitchen sink up with water as hot as I could get it. I used the hot water to transfer heat to the oil through the bottle. This will help the oil get where it needs to go, quicker.
Ideally, I would get the pump sprayer up to about 30psi and the engine would report back something steady over 20psi. As I started pumping oil in, it only took about 10 seconds for the pressure gauge to start coming up. Within about 20 seconds, the pressure gauge showed 20psi. Awesome!. In all, it took about 5 minutes to pump in 3 quarts. I rotated the crank 90° every 45 seconds. This took far less time than I expected, so I drained the oil and did it a second time. The best pressure I could get was 26psi at the sprayer and 21psi at the engine. No leaks either. I'm very happy with this. Prior to actual first startup,, I will drain this oil and prime one last time.
