Setting Valves and Injectors CAT 3116 Diesel Engine

Mechanics Hub - March 11, 2014

Setting Valves and Injectors on a Cat 3116 Diesel Engine

Our fleet starting getting Cat 3116 diesel engines in the mid 1990s and we ended up with 13 in total. Caterpillar delivered a lot of these diesel engines during the late eighties and mid nineties. There are still many of these models running around so I want to share some maintenance information on setting valves and injectors.

I have had a lot of experience with these engines mainly because a few of them dropped an exhaust valve so a complete rebuild was required. The block does not have dry sleeves so this meant removing the complete engine for repair. I also had the advantage of factory training which is a huge asset when working on the 3116.

I won't get into the rebuilding details but I want to stress that it's very important to keep the valves adjusted properly so nothing like the above happens unexpectedly. The tools for just the valve setting alone are basic...all you need is a metric combination wrench, screwdriver and .015 and .025 feeler gauges.

The one thing you can't get away from with the 3116 is buying the tool kit for adjusting the top end. For timing the injectors you need a dial indicator # 1U-8869, contact point # 9U-7274, timing gauge block # 9U-7269 and a magnetic base # 123-4940.

Setting The Engine Position for Valve and Injector Adjustment

The first position the engine has to be set on is # 1 Compression. Since # 6 cylinder is on the same throw on the crankshaft it will be on Top Dead Center along with # 1. All you need to do is rotate the engine over using a socket on the vibration dampner bolt while watching the exhaust valve on # 6 cylinder.

When the exhaust valve starts to close and the intake valve starts to open stop there. This valve over lap will indicate that # 1 cylinder is on compression stroke with both intake and exhaust valves closed with both valves moving freely.

At this engine position half of the injectors and valves are ready for adjustment.

Adjust #3 #5 #6 injectors. The timing specification is on the valve cover and the dial indicator has to be calibrated before checking injector timing.

Adjust: Intake Valves #1 #2 #4 to (.015 in.)

Adjust: Exhaust Valves #1 #3 #5 to (.025 in.)

Rotate Engine 360 degrees to #6 compression stroke.

Adjust #1 #2 #4 Injectors

Adjust #3 #5 #6 Intake Valves

Adjust #2 #4 #6 Exhaust Valves

The 3116 Cat Tool Kit

As I stated before the valves can be adjusted with basic tools but the other procedures need to be performed with the CAT tune up kit. The fuel rack synchronization, injector timing and full fuel setting can not be done without these tools. If you have a fleet of these engines it would be well worth it to purchase the tool kit.

I hope you got something out of this post and please share your experiences and thoughts below. Thank you for hanging around and if you are looking for an interactive mechanics forum join up with where you can ask questions and contribute your knowledge.

Diesel Engines