​ELDs And Glider Kits

Fernando DeMoura
January 2018

I had some interesting conversations last week about which Series 60 engines are ELD exempt and which are not. The webpage link below is from www.fmcsa.dot.gov. It looks a lot like the old rule that allows glider kits to run pre-emissions engines. So it’s the year of the engine and what year the engine was registered as that determines if a truck can be ELD exempt. So the real question is, when so many Series 60 engines are put together with a mix of parts from different model years what year is the engine?

Two years ago I thought a 1994 GK block running 1999 500hp BK injectors and a late 2002 camshaft was strange. There is no factory program for something like that. No recommended camshaft settings, or performance numbers were known. I was left to decide what injection timing this thing should run. I called an engine like this a Frankenstein. Over the last two years these engines have become more and more common and I’ve had to change the way I look them. I’ll admit some combinations actually work and if the fueling and timing are matched up in the programming some combinations work well. Given how common these changes have become over the last few years I’m almost to a point where I don’t bother listing the model year anymore. If I’m having a problem issuing a model year for a Frankenstein engine then how are glider assembly inspectors or DOT inspectors going to determine a model year?

Some of the biggest names in the glider business standardize their Series 60 engine configurations by using DDEC IV programs originally intended as a field update for Series 60s that initially ran a DDEC III from the factory. The engine serial number used for these gliders is from an early 1998 however the pistons, injectors, and usually the block are from a later model DDEC IV. That’s a Frankenstein engine. In most cases the only thing that’s 1999 or older in these trucks are the programmable serial numbers and the camshaft…and as I understand it as long as they are registered as a 1999 or older these trucks are considered ELD exempt.

That’s something to think about before you build a glider. The difference between being ELD exempt or not might just be the which engine serial number you want to use and what you have programmed into your DDEC.


Written by Fernando DeMoura, Diesel Control Service LLC.