Timing meters

[jik]

I was wondering what kind of timing meters are used on Diesel engines. Type & models.
Thanks,
Jik

[NH2112]

There are 2 kinds of timing meters used on diesels, the injection pulse and luminosity probe type. An injection pulse model works a lot like an inductive pickup light used on gassers, with a piezoelectric pickup that clamps to an injector line and converts the mechanical pulse of injection to an electric signal that triggers the light's strobe. The luminosity probe type is a little more complicated, with a clear "window" that's inserted into a glow plug hole and a magnetic pickup that mounts to the crank pulley or damper. The actual combustion event is viewed through the window, and the number of degrees before or after TDC that combustion takes place is determined.

They both have their advantages and drawbacks. The injection pulse type is quick and easy to set up and doesn't involve removing a glow plug, but on higher-mileage engines injection and combustion are going to be farther apart than on a newer one. The luminosity probe type is more involved to set up but tells you when combustion actually takes place, which is obviously more important than when injection happens - if injection takes place at the correct time, but combustion doesn't occur till several degrees or more ATDC you won't be getting all the power the engine's capable of making. So, for the most accurate timing, it's probably best to use both types of meters.

[britannic]

I have a Snap-on MT-480 (analogue meters) and a Ford Rotunda 78-0100 (digital) - both are lumy/mag style and are very accurate once the timing offset is dialed in (don't use #1 cylinder with the 9.5 degree offset on this type of meter, as there isn't enough time for the mag pickup to signal the meter's computer).

The later Snap-on MT-1480 (digital) has more bells and whistles

[aloharovers]

I have the snapon injection pulse timer. I do like it. But I have noticed that the clamp is very sensitive. Its possible to have it on too tight or too loose which fails to signal the timing light. Other then that it works.
I havent tried a luminocity probe so can not compare them smile.gif