Opacity testing and Biodiesel.

I thought you may be interested in these results. These test were performed by my class after we had covered alternative fuels and opacity testing. The opacity tests were done on a Smoke Check 1667 opacity meter (Colorado state certified SAE J1667 Opacity test). The Biodiesel was some of mine from home except one test so noted, that was made in class. The biodiesel used passed both the water separation test and the 3/27 test. The engines used were from the Engines class and are torn down and rebuilt each school phase (5 week period) by students. Differences in results were from: (Detroit vs. Cat) differences in injection system type and (Detroit vs. Detroit) differences from student rebuild of injectors, valve settings, etc. Temp readings were taken at the exhaust manifold. Each result is the final average of three tests. First test of each, the temp is slightly lower due to the engine not being quite warmed up.

Test #1 1991 Detroit series 60

Fuel type/ Temperature/ Opacity %
Petroleum / 213` F / 25.4%
Biodiesel / 222.5` F / 21.5%
Petroleum / 231.5` F / 29.1 %
Biodiesel / 221.0` F / 23.1%

Test #2 1996 Cat 3406

Fuel type/ Temperature/ Opacity%
Petroleum/ 191.5` F / 6.5%
Biodiesel/ 235` F / 2.75%
Petroleum/ 241.5` F / 5.33%
Biodeisel / 229` F / 2.5%

Test #3 1991 Detroit series 60

Fuel type / Temperature/ Opacity%
Petroleum/ 190` F/ 22.6%
Biodiesel (classbrew)/ 215` F/ 17.5%
Petroleum/ 230` F/ 33.8%
Biodiesel/ 215` F/ 19.2%

Thanks to Mike Slicker for the use of his engines and to Ashlie Martinez, Kevin Meyer, and Levi Treese (three of my students) for cleaning & operating the opacity meter, and recording (and crunching the numbers!) the results. Videos and pics were taken and I will try to post as soon as we get that sorted out.

Thank you for sharing these rsults

Ditto!
Good job,
Jon

dumb question here..

but is the lower number of Opacity better??

just when I start to think i know something..I get surprise again? got love BD making always something new.

-dkenny

quote:

is the lower number of Opacity better??

Yes.

With B50 my truck tests 0% opacity and 10ppm HC. Very clean by 'diesel' standards.

I was guess that was the case, but thought I ask to be sure.

we don't have opacity testing here in NC..but I've never seen smoke come of of my Cummins..

-dkenny

Those biodiesel numbers are much higher than I would have expected, maybe the enignes are not broken in enough to get good results for bio?

In AZ the state standard for opacity is a measurement of 40 or lower, on dino my truck was 60 blech! On Biodiesel the same truck was 2.3, Thats a huge difference!

And yes Dkenny, lower is better
The higher the number the bigger the black clouds are that come from your tailpipe(s).

Opacity is the measure of how much visible soot is in a deisel exhaust. The lower the number, the cleaner it is running. The engines being tested are used to teach students how to rebuild heavy duty truck engines. They are well broke in but individual adjustments (valve lash, injector pump setting, injector shimming, etc) will make the differences. And the engines are on engine stands not in a vehicle. Also, they push these engines to the limit of power and still (sometimes lol) keep it legal. One student had rebuilt his personal pickup engine (cummins) with custom injectors, chipping, tuned pump, etc and the blew a 100% opacity! We had to completely tear down and clean the opacity meter. That truck is fast!

quote:

One student had rebuilt his personal pickup engine (cummins) with custom injectors, chipping, tuned pump, etc and the blew a 100% opacity!

Is that amount of pollution legal?

NO! The legal maximum amount of opacity in Colorado is 40%. The student gets that reading when he has the chip turned up and floors the accelerator. After the testing he shut it down (the chip)and greatly reduced his soot output (Kids will be kids). He will probably be ticketed for that if he does it on the street and is seen by Denver PD. Most mechanics end up turning a wrench because of an interest in performance when they are young. I try to get them involved in alternative energy as a different direction to go in. Sometimes it works, sometimes not. At least give them a different perspective.