High Performance Diesel Engines April

Movin' Out Magazine
April 2016

Back in the 1980’S Cummins Engine Company made a .013 thicker head gasket for engine blocks that were resurfaced. It was an ingenious idea, because as the block is resurfaced the compression ratio of the piston is increased because it’s now closer to the top surface of the block. As compression ratio increases, the volumetric efficiency decreases and the horsepower decreases. Volumetric efficiency is the engine’s ability to ingest air. A turbocharged engine with a lower compression piston will ingest more air than a high compression piston. So when the block is resurfaced the compression ratio is raised. The .013-inch thicker head gasket for the Big Cam Cummins Engine was an ingenious idea and now with all of the diesel engines being overhead camshafts it’s even more of a problem. As the decrease in deck height moves the camshaft and cam gear close to the idler gear it rotates the camshaft. This is a particular problem with the 12.7 liter 60 Series Detroit. Think about this, when the head is resurfaced it also moves the camshaft closer to the idler gear. So with resurfacing the block and the head, this problem is compounded. This is a necessary evil; blocks and heads must be resurfaced in order to maintain a good seal of the head gasket. At Pittsburgh Power we discovered this problem with the 12.7 Detroit while building several engines for our clients. There was not enough material to resurface the block and maintain the proper piston to deck height. At this time, we were not thinking about the rotation of the camshaft, we were more concerned with the compression ratio going too high and loosing performance. The valves can also hit the piston during a hard pull if the piston to deck height is too high. We are always looking for cures for the engines we work with and knowing the Cummins .013-inch gasket for the Big Cam solved this problem we wanted a head gasket for the 60 Series Detroit that would restore the piston to deck height. It’s taken one year to design and have manufactured a .012-inch thicker head gasket for the 60 Series and the first one is now in service. On the dyno we gained 27 horsepower to the rear wheels without changing anything other than the head gasket, and the gear train on the front of the engine became a lot quieter. Other changes we noticed was the engine ran smoother, was quieter and smoked less even when the engine was cool. If you are in the process of having your 60 Series rebuilt, please have your mechanic check the piston to deck height with a dial indicator and if it’s near the minimum spec you just might want to install a Pittsburgh Power .012-inch thicker head gasket.

The new programs we have developed for the 2008 and newer ISX Cummins continue to impress us, with all of the emissions intact, the horsepower to the rear wheels is 600, which is 705 flywheel horsepower, and the torque is 2150 pound feet. This engine is compliant and you can take your truck into any truck or engine dealership and it will pass the emissions. We currently have four of the ISX Engines running with this tune, and the emission related problems have diminished. We feel that we will need to do an emissions tune up about every 250,000 miles and expect to see these engines run in excess of 1 million miles with EGR, DPF and DEF running perfectly. For the past 39 years we have always looked for ways to improve the Cummins Engine and we feel that we have hit a HOME RUN for owner-operators with the 2008 and newer ISX Cummins keeping the engine completely legal. You can now have horsepower, torque and fuel mileage and run in and out of California and be completely legal and smoke free.

The Owner-Operator Snowmobile Conference is now over and all who attended had a wonderful time. We had a total of 27 people, 6 of them were women and we met at the Togwotee Mountain Lodge in Wyoming. The riding on Friday was good, Saturday it snowed most of the day and we still rode and Sunday, we had great riding. Saturday night we watched the movie “Convoy” and like last year as we watched “Smokey and the Bandit”, the comments for owner-operators are always entertaining. It was neat to see the old trucks that many of us have driven and worked on. This was our eleventh year riding together and many of the owner-operators want to get together twice next year. If you have never participated in a motorized sport with a group of owner-operators, you are missing out on a great time. We talk trucks, motorcycles, and snowmobiles and ride hard on the mountains. We really need to get together to do a motorcycle trip someday.

I want to say thank you to Michelle Buzalsky of Riverton, WY for being our tour guide and avalanche patrol. She is the president of the snowmobile club in Riverton and a trained avalanche instructor. Her husband, Keith, is an owner-operator and mechanic and we really enjoyed their company.

For next year, we will have two Owner-Operator Snowmobile Conferences, the first one will be at the end of January and the second one will be the end of February. I know most of you will not be able to attend both of them, however several of you will because it was your idea to get together twice a year to enjoy each other’s company and ride snowmobiles together.

Written by: Bruce Mallinson and John Walko, Pittsburgh Power Inc., 3600 South Noah Dr. Saxonburg, PA 16056. Phone 724-360-4080