Today I am going to show you how to adjust the valves and injectors on a Caterpillar 3116 Diesel Engine. The injectors are mechanical and are checked and adjusted manually using the appropriate Caterpillar tune-up tools.
Here are the tools needed to perform the valve and injector adjustment: Caterpillar Part #'s
*Dial Indicator # 1U-8869
*Contact Point # 9U-7274
*Feeler Guage # 123-4941
*16mm/18mm Drop Wrench # 128-8824
* Timing Guage Block # 9U-7269
Magnetic Base # 123-4940
Setting the valves and injectors is a preventive maintenance operation and should be done on a regular basis. Once you get through one setting it's a cakewalk the second time around. Below is the dataplate that tells you the timing specification for setting injectors.
The dial indicator has to be pre-set so it reads 62.00 mm when placed on the timing guage block as shown below. These tools come with the complete Caterpillar tune-up kit with detailed instructions included.
The first thing to do is rotate the engine over until # 6 cylinder valve rockers are rocking. Watch # 6 valve rockers as you are rotating the engine, keep turning the engine until the exhaust valve closes and the intake valve JUST starts to open. Stop there, # 1 cylinder is now on the Compression Stroke and ready for valve adjustment as well as the other designated injectors and valves.
*Adjust 3-5-6 injectors to timing spec. / in this case 65.74 mm / + or - .020 mm
*Adjust 1-2-4 intake valves .015 in.
*Adjust 1-3-5 exhaust valves .025 in.
*Adjust 1-2-4 injectors
*Adjust 3-5-6 intake valves
*Adjust 2-4-6 exhaust valves
As you can see from the above picture the magnetic dial indicator holder sits on top of the injector. The dial indicator measures the distance from the top of the injector to the machined body surface at the bottom which must be set correctly. This dimension effects injection timing and can be adjusted at the injector rocker arm set screw.
I hope this post helps out all you Cat 3116 owners. The valve and injector adjustment is probably the most crucial as adjustment can change with normal wear and tear as your diesel engine racks up the mileage.
That's all for now, thanks for visiting and be sure to check back for more Diesel Mechanic Tips.