Eliminating Performance Roadblocks on a '94 to '98 5.9L Cummins Diesel

While reading a Driving Line story about 5.9-second diesel drag trucks, another story caught my attention. It was an excellent tutorial on how to get more performance and power from a mid-90s Cummins diesel engine. We'll give a brief overview here of the highlights and then link to the story, which includes photos that illustrate exactly what is being described.

Don't you hate it when something is explained but you have no clue how to do it because you don't know exactly what you are looking for. This article shows and tells, and is worth bookmarking.

The article by Mike McGlothlin, published last summer, is titled Performance Roadblocks of the '94 to '98 5.9L Cummins. This particular Cummins hit the road in '94-'98 Dodge Ram three-quarter and one ton trucks. 

The article opens by noting how durable the Cummins engines of this period were. 500,000 miles is not unusual at all with a few performance modifications. The factory setup was somewhat conservative for this engine, however, so get get the most from it McGlothlin zeroes in on the various ways this superb engine could be improved.

Roadblock 1: The P-pump
This is a Bosch P7100 mechanical injection pump, a "little engine" on the engine. Because of its factory setup the P-pump is more of a limiter than contributor of power. Hence, the starting point for more power is to move this roadblock.

The goal is to modify the air-fuel ratio. To do this, adjust the AFC (air-fuel control) by adjusting the pre-boost screw. (The article includes photos so you know where to find it.)

The second adjustment is to tweak the star wheel that sits on top of the AFC housing. By gingerly rotating the star wheel toward the passenger side you will increase the engine's power. If you go too far you will have black smoke that you do not want, so tweak accordingly.

The third adjustment again focuses on the AFC. Bring the AFC forward as far as it will go. The author writes, "Combining a full-forward AFC with the aforementioned star wheel rotation, it’s not uncommon to see a 60hp and 200 lb-ft gain."

His fourth trick is to have you remove the P-pump's fuel plate. To do this you will have to remove the AFC housing. These four moves alone will make a difference and cost nothing to implement. He then turns to a couple of "cheap" maneuvers.

His "Cheapie Fueling Fix #1" is to pick up and install a $15 Mack rack plug. This alone will add up to 35 hp to your truck. His "Cheapie Fueling Fix #2" is a timing adjustment.  

Roadblock 2: RPM
The second Roadblock, McGlothlin explains, has to do with RPM, or lack thereof. "If you perform all (or even some) of the fueling mods listed above, your power band will remain limited until you address the factory governor springs." The solution he says is to get a 3,000 RPM governor spring kit.

Roadblock 3: Lack of Boost
The adjustments you have made so far should have added 100 hp and 250 ft-lb. of torque. But the with factory turbo untouched, you're missing out on the full potential this engine offers.

His first suggestion is to install a boost elbow. This is a $25 item that enables youto fine-tune boost. It comes with precautions, though. 

Roadblock 4: Factory Torque Converter or Clutch
Another weak link to consider addressing, especially after you have removed all the other roadblocks to performance.

If this kind of thing interests you, but you have a different kind of engine, be sure to check out the forums (listed in the right hand column of this blog) where a lot of smart and experienced people gather to share ideas and help their fellow diesel friends.

You will find the Driving Line article here. 

Winners and Photos from Last Weekend's East Coast Diesel Nationals Gives

All photos courtesy Diesel Motorsports

For a lot of people, their first exposure to diesel competition took place at a county fair.  County fairs are a tradition as American as apple pie. In fact, your first apple pie might have even been at a pie eating contest at a county fair. Fairs give communities a chance to show off what is special in their communities. They are also lathered with nostalgic memories, becoming a gathering place for young and old alike. 

These thoughts came to mind when I read this headline from the Journal-News: County Fair Tractor And Truck Pulls Rescheduled (Again) For Aug. 22. It was that word "Again" that tipped us off to the biggest challenge all motorsports promoters face: the weather. 

EAST COAST DIESEL NATIONALS 2021

This past weekend in Numidia, Pa., the day opened with a bright sun scattering its arrows of light across the landscape. It seemed a good omen, since the East Coast had been receiving buckets of rain nearly daily for a week while a large swath of the country has been experiencing a drought.

Unfortunately the day's events were later cut short... by more rain. Despite the weather, racers persevered and we had winners in a number of categories so the the day was not a complete washout. The 2500+ attendees who came to Numidia saw 175 competitors in a limited event that included racing, pulling, dyno and Show-N-Shine.

Champion Blue Flame Oil is pleased announce the following winners for the East Coast Diesel Nationals last Saturday in Numidia, PA.

 

ET Bracket

Champion – Jake Allison

Heads -Up

Champion – Marlin Shirk

Sled Pulling

WorkStock

1 – Matthew Fessler – 339.19

 

Hot WorkStock

1 – Tom Hassler – 317.95

 

2.5/2.6 Class

1- Brenden Finck – 315.28

3.0 Class

1 – Jared Brown – 342.68

 

2WD 6200 LB Trucks

1 – Dale Forrester – 311.39

 

8500 LB Mod Tractors – (Single/Multiple engine)

1 – Vern Zerby – 315.81

 

7800 LB Tractors
1 – Amber Blizzard – 351.12

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Diesel Motorsports is the official sanctioning body for this event. In addition to tractor pulling and drag racing in multiple classes, there's a Show 'N Shine and a Dyno competition. The full range of events can be found here. 

Special thanks to Ron Knoch and the Diesel Motorsports team for doing all they can to make their motorsports events to be a rewarding experience for diesel enthusiasts and their fans. Here are a few additional photos from this past weekend.

Here is a list of upcoming Diesel Events.

If you know of an event you'd like us to add,

place it in the comments. See you at Rocky Top.

Ford Walks Back on Diesel F-150

This past week the news spread like a California wildfire. We read about it in several articles. This one by Joe Patel, from Cars Direct, has a pretty good summary of the report. 

Many observers noticed the absence of a diesel option in the 2021 F-150 last year, but then Ford seemed to have a change of plans and the Power Stroke V6 became available later. This year, Ford Authority announced that the diesel engine for F-150s is to be a thing of the past. This leaves five engine options for F-150 buyers: a 3.3-liter V6, turbocharged 2.7-liter V6, turbocharged 3.5-liter V6, hybrid turbocharged 3.5-liter V-6 and a 5.0-liter V8. 

According to Car and Driver, it's the popularity of these other engines, such as the EcoBoost, that led to this decision. July 16 was the last day one could order a Power Stroke diesel option.

Cars Direct stated that this last Power Stroke V6 showed some real grit when one looks at the numbers it generated. 250 hp and 440 lbs-feet of torque is nothing to scoff at. But according to Patel, the availability of a hybrid overshadowed that power.

This is not the end of diesel engines at Ford. Diesel is still "available on the XL, XLT, Lariat, King Ranch and Platinum trims  with four-wheel drive." The extra cost varies from $3k to $5k. With a diesel engine the F-150 has a towing capacity up to 12,100 pounds or a payload capacity of 1,840, numbers that fall short of what Chevrolet and Ram offer. In fact, even the hybrid V6 has more oomph when it comes to torque (12,700) and the v8 as well (13,000), both of these being outdone by the turbocharged 3.5-liter V6 (14,000 pounds).  

The Cars Direct article concludes with a reiteration of Ford's commitment to be carbon neutral by 2050. The all-electric F-150 Lightning and their Mustang Mach-E are the first signals indicative of their seriousness in this effort. "Offering a diesel powertrain doesn’t exactly help the automaker with these goals. Ford didn’t help the diesel engine’s case, though. As Ford Authority points out, the diesel engine wasn’t available with the 36-gallon extended range fuel tank or the automaker’s Pro Power Onboard system."

The departure of the F-150 diesel is not the end of the world, but it is the end of an era.

Read the full story here: F-150 Diesel Engine Discontinued

The East Coast Diesel Nationals and Thoughts on Why Motorsports Competition Matters

Photo courtesy Diesel Motorsports

Tomorrow the East Coast Diesel Nationals will be underway. As you read this, teams and enthusiasts are packing their gear or already on the road. Promoters are setting up to make everything is fan-friendly, or tying sponsor banners along fences and talking with the media. 

To give you an idea of the scope of the East Coast Diesel Nationals, here's a Diesel Army story about their 2017 event here. The Official Oil this year is Champion Blue Flame Diesel Oil, which you may have read about in The Shop Magazine.

Diesel Motorsports is the official sanctioning body for this event. In addition to tractor pulling and drag racing in multiple classes, there's a Show 'N Shine and a Dyno competition. The full range of events can be found here. 

THOUGHTS ON MOTORSPORTS RACING 

Some of us have been involved in racing nearly all our lives -- many as fans, and later some of us as drivers, and still others as sponsors. What's evident is that there is much more to racing than simply trying to see who is fastest. There are economic benefits, social benefits and many other benefits not immediately observed. 

In 2017 Automotive News published an insightful article on why racing matters. It begins with an anecdote about Henry Ford, who in 1901 beat the country's most famous racer in a 10-mile dash. One result of this victory was that it attracted investors into a fledgling company that has continued to this day.

The Automotive News editors were intrigued that whenever they had long discussions with auto industry leaders, somehow the conversation often drifted to racing. The AN editors came to realize that racing was itself a microcosm of the industry. 

In 1963 Roger Penske significantly observed that racing is not about individuals doing magnificent feats. "You're dealing with a team sport here, not just an athlete."

When you go to a diesel competition, you'll see how much these are truly team efforts. It would be fascinating to study how the character of leaders is such that their mechanics will stay up all night to get their vehicle ready for the next day's race.  

There's more to racing than what takes place on a weekend, though. All the top teams are gathering data that is used to for improving the vehicles in production for the masses. Whether it's dirt bikes, snowmobiles cars or diesel trucks, data is being gathered and innovations are being noticed in Detroit and elsewhere. 

* * * 

For those who love trucks simply for their beauty, the East Coast Diesel Nationals is the place to showcase your passion. Here are a couple Show 'N Shine stars from the past. Maybe your truck is the one that will shine tomorrow.

Photos courtesy Diesel Motorsports

Related Links

Why Sports Car Racing Still Matters (Motor Trend)

What Matters More in a Race: The Car or the Driver

Diesel Events: East Coast Nationals 2021 

Top Service Tips for Hard Working Diesel Engines For Operating at Peak Performance

Yesterday we wrote about three reasons diesel engines overheat. Upon seeing today's article about maintenance, it seemed like a good follow up and worth sharing. Rental is a publication for construction pros, but it's relevance is for everyone who owns a hard working diesel.

As we all know, there have been lots of changes in engine technology the past two decades, and this current decade we're seeing an increased transition for diesel to EV in many realms. In this article the author, Alexis Sheprak, reached out to three leading engine manufacturers to discuss some of the challenges this presents along with tips on how to improve the way we take  care of our equipment.

The three manufacturers she spoke with are Cummins, Perkins and Hatz. The question she asked was "What are your top five service tips for larger diesel engines to maintain peak performance year-round?" Here are the suggestions Rental's readers received. For the purpose of brevity, the suggestions are abbreviated and paraphrased. You will find a link to the full article at the end of this post.

Hatz
1. Follow the maintenance schedule as outlined in the owner's manual. If you're working in a harsh environment, however, make adjustments accordingly. (He uses the example of air filters plugging sooner than normal in extremely dusty environments.)

2. Because their is more electronics on engines these days, use more care when power washing.

3. Monitor your diesel particulate filter (DPF). Do not ignore warnings.

4. If you're running idle much of the day or low-load conditions, "make sure you run the engine at full load for at least 30 minutes at the end of a shift to ensure the diesel oxidation catalyst (DOC) is reaching the appropriate burn out temperatures."

5. Pay attention to engine codes, and have them diagnosed as early as possible.

Cummins
1. Use the correct parts.

2. Following recommended maintenance schedules is critical. "Preventive maintenance saves fuel costs, major repairs in the long-term, and maximizes the productivity and life of the engine."

3. Use the correct fuel, oil and DEF. (Also, regularly check tire air pressure and air filter cleanliness.)

4. Engine filters are becoming more technically advanced. Make sure you are using filters that meet standards.

5. If you have a Cummins, they direct you to their service website, quickserve.cummins.com.  Enter your serial number and you're good to go.

Perkins
1. "Engine oil sampling, change intervals and oil grades." Keeping your oil health is critical, especially heavy working engines under load.

2. "Coolant condition and system performance." Overheating does all kinds of damage as we noted here yesterday.

3. Pay attention to fuel cleanliness and filtration. Failure to pay attention to these will cost you money down the road as it impacts fuel pumps and injectors.

4. Be sure you adjust for the seasons. (Here are some winter maintenance tips from the Blue Flame team.)

5. DEF handling and cleanliness. Also, when storing DEF keep it out of direct sunlight in a cooler storage area. It should not be above 95 degrees F.

* * * 

Additional questions that these engine professionals answered were as follows:

Q: New advanced engines and cooling systems are changing cooling system maintenance requirements. What should rental houses pay attention to when it comes to cooling systems?

Q: What about proper fuel maintenance?

Q: What technologies are available to help monitor engine performance and manage service schedules?

Q: I know there’s been a big push lately for more sustainability. What are some of the latest advancements in fuel types? And what should rental equipment owners be aware of about them?

Q: What’s next for engine technology?

* * * 

This article is packed with valuable, authoritative information. You can find the full article here: Diesel Engine Maintenance Tips for Peak Performance

What Are the Three Main Causes of Diesel Engines Overheating?

On Monday Truck Parts & Service published an article about the causes of diesel engines overheating. Being that we are currently experiencing one of our hotter summers on record, it seems like a good time to review causes of overheating diesels. This particular article by Bill Grabarek is addressed to heavy diesel equipment, but it applies to all hardworking diesel engines. 

An overheating engine can produce serious damage. Head gasket failure and cracked cylinder heads will give you more than a head-ache. Sometimes the damage is so severe, such as a cracked engine block, that it is irreparable.

Perhaps you have had the experience of trying to remove a metal lid that is stuck on a glass jar. One way that often works is to run it under hot water. The heat causes the metal to expand, liberating the lid from where it has adhered to the glass. 

This principle of thermal expansion is what's going on when your engine gets hot. The author points out that the normal operating temps for an engine should be between 190 and 220 degrees. Increased temperatures beyond that will put stress on the cylinder head, liners and engine block, he says. Overheating beyond these acceptable ranges "causes these parts to expand beyond the engine's tolerances." To fix the damage can run into thousands of dollars, and for larger heavy equipment the bill can amount to tens of thousands of dollars. 

All this to say that it's worth reminding ourselves of a few basic steps to avoid such a disaster. In short, a stitch in time saves nine. This is the essence of preventative maintenance.

Mr. Grabarek cites three basic causes of diesels overheating. 

Low Coolant Level or Coolant Loss
One cannot assume that they won't overheat, even if they have the correct coolant level according to the manufacturer's recommendation. Nevertheless, it is important to routinely check fluid levels because this is the first sign you'll have that there is coolant loss taking place. 

There are a variety of areas where one can have coolant leaks. Hoses, gaskets, water pump, thermostat, heater or freeze plugs are just a few places to look. Often you can smell a coolant leak. A cracked cylinder head can also be the culprit, which will sometimes produce white smoke from the tailpipe. 

Air Pockets in the Cooling System
This is a problem that can develop when replacing coolant, or when the  coolant has been drained for a repair job. Air pockets may form when refilling. These air bubbles can interfere with the flow of coolant through the hoses. If these air pockets aren't bled from the system the engine can overheat. 

Faulty Thermostat
Thermostats regulate the amount and flow of coolant by responding to temperature changes in the engine. When the engine gets too hot the thermostat opens to allow more coolant to flow through. Thermostats are a valve that can sometimes get stuck, however. In such cases they need to be replaced.

* 

The article ends with instructions on how to bleed the air from your cooling system. You can read the full story here.

'58 Oldsmobile 88 Diesel Rat Rod Lowrider Makes Waves on Social Media

1958 Olds, getting the Rat Rod treatment.

The SoCal street rod scene has deep roots stretching back seven decades. Through the medium of Hollywood, street rodding became a transcontinental phenomenon. 

During that evolution, car collectors invested increasing amounts of time and money into creating pristine showcase vehicles that are strikingly beautiful. Just as a few of today's billionaires compete in a rich man's space race, so we've found others who seek out premiere builders to win them awards. "Whatever it costs, I want you to win me a Ridler Award." 

It was against this backdrop of perfection and prestige that the rat rod scene emerged. Instead of seeing who could spend the most money to re-create the perfect dream car from the past, rat rods allowed wrench-turners and welders to focus on creative self-expression. You didn't have to worry about a perfect paint job. In fact, the grittier the better.

A lowrider look is the final vision for this build.

What caught our eye about this rat rod build featured at autoevolution.com was how they dropped a diesel engine into a 1958 Oldsmobile 88. Those were the days when an auto body was truly substantial. Some cars were built like a tank. Fuel was abundant and cheap. Style took precedence over aerodynamics. Fuel economy wasn't even a consideration.

According to the article by Aurel Niculescu, the 88 as a brand was born in 1949 and had a 50 year lifespan. Some considered the late Fifties era to be a forerunner to the 60's Muscle Car era.

The car featured in this story was created by THD Performance. (THD is short for True Horsepower Diesel.) The author notes that THD specializes in all things diesel, including Cummins swaps and fabrication. It's obvious they have fun in the Rat Rod realm as well. 

Now that we live in the social media age, it's no longer good enough to create a car and use it for local cruising. Which leads to the next part of this story. THD Performance asked Dom Höst, a pixel artist, to make a dream version of what they were intending to create so they could share it on Instagram.

There weren't a lot of details posted, other than the fact that it's likely to be powered with a Cummins diesel. The author speculates it will likely be mated with a twin-turbo companion kit. 

If you want to see some very cool builds, you should check out their gallery on Instagram Do a search and you will find them at truehorsepowerdiesel. 

The original article about the build can be found here at Autoevolution.  

Follow THD Performance on Facebook here.

Here's another build they've been working on at THD.

Do you have a cool diesel ride that you're proud of an want to share? Tell us about it in the Comments section and leave your contact info. We'd like to see it and share it here.