Unfortunately, my beloved truck fell victim to someone's recklessness. It seems they took it for a spin while their own vehicle was out of commission. My suspicion is that they pushed the RPMs too high, causing damage to the cam follower and camshaft. Now, I'm wondering if the camshaft can be salvaged, or if it's better to just replace it entirely.
It appears that the outer edges of the cam lobe are showing signs of copper wearing down to the core material.
I would advise against taking the risk of not addressing the issue now and instead, it may be worth looking into further. Saving a little money upfront could end up costing a lot more in the long run. Is there a possibility that the equipment is already halfway toward needing an overhaul while it's currently out of commission? That situation is unfortunate, I can empathize with your frustration.
Before my purchase, the vehicle had recently undergone an inframe overhaul with documented paperwork. The inframe has around 11,000 miles on it. It seems that the previous work may have overlooked setting the overhead and cam followers correctly, resulting in issues with the number one cylinder and a bent push tube at 9500 miles. This was likely caused by a sticking cam follower, which has now been identified.
That sequence of events is quite revealing and noteworthy.
I believe the issue may have been related to a misadjusted injector or a faulty jake brake, rather than a sticking Cummins cam follower. This is not a common problem that is typically heard of in the industry.
Additionally, we installed a new fuel injector for the cylinder experiencing fuel blubbering issues caused by a misadjustment.
I am hopeful that we can resolve the issue with my beloved truck, which is my favorite vehicle in our fleet. I plan to keep it as my personal hobby truck once it retires from active duty.
Hallback mentioned that they replaced the injector for a cylinder that was spewing fuel due to a misadjustment, which raised concerns. Is it the same shop handling the repairs on both occasions?
The root cause of the problem stemmed from a misadjusted injector, which caused the push tube to become bent. Despite replacing the push tube and correcting the injector alignment, the damage had already been done and the issue persisted, leading to the emergence of a new problem.
Which large cam is it, III or IV? When replacing the cam and followers, be sure to also inspect the cam bearings. I typically adjust II's and III's so that they are slightly behind based on the timing code. For example, if the timing is at 70, I would set it at 72 or 73 to allow for more hang time between shifts. It's important to consider whether the cam was changed during an inframe overhaul. Over-fueling an engine by 20% or more can significantly reduce the lifespan of the camshaft, particularly if driven aggressively. Excessive fueling with stock injectors increases pressure on the cam lobes. Ideally, stock rail pressure should be around 185, but mine would reach 300. By switching to ten orifice injectors, the pressure dropped to approximately 240, which is still relatively high. I monitored fuel pressure using a liquid-filled gauge to ensure everything was functioning properly, especially during intense acceleration. One interesting anecdote about my engine in a '66 vehicle with a KT 1" pump and ten orifice injectors is that under constant heavy throttle, the pyrometer would reach 1100 degrees. However, when I would suddenly release the throttle, the pyrometer would drop since the cylinders were being flooded with fuel. This engine was truly a standout at the Truck Shop.
In response to RZucker's comment about a potential can of worms being opened, the question was raised about whether it was the same shop on both occasions. "I'll take two of those worms and raise you four spiders," was the playful retort made in jest.
The Truck Shop owner confidently declared, "I'll see your two worms and raise you four spiders." This shop is not for the faint of heart, with giant black widows lurking under the benches. These spiders are crucial for controlling the mouse population, so be sure to thoroughly inspect each box before grabbing it.
When working on a truck engine, it is essential to identify whether it is a big cam III or IV. The first step is to replace the cam and follower/followers and inspect the cam bearings. For optimal performance, timing should be adjusted accordingly based on the timing code. Setting II's and III's slightly advanced can enhance shift transitions with timing set slightly higher than the original code. It is crucial to consider the impact of previous over fueling on cam life, as excessive fueling can significantly increase pressure on the cam lobe. Monitoring fuel pressure with a gauge is recommended to ensure the engine is operating efficiently under heavy throttle. An anecdote about the writer's experience with a specific engine highlights the importance of engine modifications being driver-specific. Trusting only oneself to make engine enhancements ensures both performance and safety on the road.
Hallback expressed frustration over his favorite truck being driven by someone while their own was unavailable. It seems that the individual may have run the truck at too high of an RPM, damaging the cam follower and camshaft. The question now is whether the camshaft is salvageable or if it needs to be replaced. It is likely best to opt for a new camshaft, as running the overhead out of sequence may have caused further damage.
Now that we've established the need for a new camshaft and rocker boxes, which supplier do you recommend for purchasing the camshaft?
When it comes to replacing the camshaft and rocker boxes, Hallback recommends going with Cummins for the parts. In his opinion, Cummins is the top choice for this type of repair.
Can you please provide me with the CPL information for this engine at the Truck Shop?
After determining that a new camshaft and rocker boxes are necessary, the next step is deciding where to purchase the camshaft. It is recommended to invest in an OEM camshaft, as aftermarket options may result in needing replacements sooner. Quality matters when it comes to crucial engine components like the camshaft.
This morning, I will have my mechanic obtain the CPL for this engine. The Truck Shop inquired, "Hallback, what is the CPL on this engine?" Click here to find out the details from Truck Shop.
I believe the CPL stands at 891.
If the overheads were not adjusted correctly, it could cause the engine to perform poorly. It is likely that the camshaft was damaged during the repair process. Visit the Truck Shop for expert assistance with engine repairs and adjustments.
The performance of the car was as swift and agile as a cat doused in turpentine. It really garnered impressive acceleration, confirming your suspicions, TS.
The 891 pump is unique in the 800 series, as it is the only one with a CPL number. Have you checked if the seal is still intact on the plunger cover at the back of the pump? If it has been modified with a #5 or #7 button and shimmed for higher RPM, it is likely used by a logger. A stock button would typically be a #32 or #37, resulting in a 35 to 40% increase in fuel delivery. This can cause a 30% over-fueled Big Cam to sound like a PC Cat, producing a noticeable rattling noise. In the past, a logger who occasionally worked on the west side used to bring his modified pump to our shop in Eburg to keep up with his peers. Visit our Truck Shop for all your pump needs.
According to Truck Shop, improper adjustment of overheads may have caused the truck to run poorly, like a sack full of a$$holes. They suspect the cam may have been faulty when it was reassembled. This humorous expression certainly caught their attention!
When adjusting overheads incorrectly at Truck Shop, the truck may not run properly. It is possible that a bad cam was the issue during the rebuild. Trucks that were worked on in this manner typically did not run well initially, requiring further adjustments and part replacements. It is important to address any issues promptly to prevent potential damage. Truck Shop used to address this by replacing bad rollers and lock pins as needed.
I have a confession to make: I once damaged several push tubes on an older smallbore 335. It was later discovered that the accessory drive was replaced without being properly timed.
I am hopeful that I can resolve this issue within the next week, as it is time for my hobby truck to retire and be put out to pasture.
Hallback, later OEM Cummins BC3s incorporate crowned camshaft lobes and rollers for improved performance. When purchasing recon Cummins lower boxes, it is recommended to use a pressurized engine oil source to flush out any debris before installation. You can use a pressurized oil source, such as a clean weed sprayer pumped to 15psi, in conjunction with a flat metal plate secured by bolts and nuts. Make sure to drill and tap a 1/8" PT hole in the lower box gasket to allow oil to enter the boxes' lube oil orifice. It is important to manually work the rockers and rollers for 10 minutes per lower rocker box to ensure proper lubrication. Use a clean catch pan and paint gun filter to check if any particles are flushed out during the process. Some may prefer using aftermarket parts like Custom Stainless exhaust manifolds for Cummins Small Cams, which feature exhaust port stainless steel stuffers to enhance flow rates and fuel efficiency. Consider upgrading with a preluber and Lower Rocker Box Plate for optimal performance. Truck Shop / RZucker.
I can't recall seeing any stainless steel parts in the III cpl, despite having worked on almost every one of them. I do not remember seeing any crowned lobes on the rollers or cams either. Can you please provide a picture for reference? This inquiry is from a truck shop.
Truck Shop mentioned that there used to be stainless aftermarket ‘pulsed exhaust manifolds’ available before the Cummins Big II was introduced in 1979. These manifolds were a product of a California off-road racing airflow expert, whose name escapes my memory. They were crafted using round 309 stainless tubing, with 6 pipes leading into a cast stainless center section resembling the Cummins cast iron pulsed manifold. The goal was to retain heat energy and increase exhaust gas velocity for faster turbo spin up. Truck Shop also noted that in their experience with Cummins camshafts, they haven't come across any crowned lobes on rollers or cams. The crowning, which is subtle and difficult to spot with the naked eye, is around ½ degree or less across the lobes parallel to the cam center line. This design adjustment was part of the OEM's efforts to prevent lobe failures after the introduction of PTD-TopStop-DFF injectors, pneumatic variable timing, and step timing due to stricter emissions regulations. The user "Pumpguy" may have access to Service Bulletins related to this topic, as I have disposed of all subscription literature and engine advertising brochures. Additionally, there are a couple of photos available showcasing a 1962 DIY prototype rear cam bearing removal tool. This tool proves useful for extracting rear cam bearings during an in-frame service without the need to remove the transmission or bellhousing.
StanRUS mentioned a unique aftermarket product from the past: Stainless 'pulsed exhaust manifolds' created by a California off-road racing airflow expert before the Cummins Big II was introduced in 1979. These manifolds, made from round 309 stainless tubing, featured 6 pipes leading into a cast stainless center section resembling the Cummins cast iron pulsed manifold. The design focused on heat retention and maximizing exhaust gas velocity for quicker turbo spooling. Cummins also introduced camshafts with crowned lobes as an effort to prevent lobe failures caused by new injector technology and emissions regulations. These camshafts had imperceptible crowning and were part of innovations like PTD-TopStop-DFF injectors, pneumatic variable timing, and step timing. Additionally, StanRUS shared images of a 1962 DIY rear cam bearing removal tool and reminisced about a custom stainless manifold he used on a DIY project with a 400 Magnum engine. The manifold helped him achieve over 435 horsepower and lasted for 162,000 miles before he sold the truck. Unfortunately, he lost contact with the buyer and doesn't know how long the setup lasted.
I have a cam bearing tool in my possession, but I have never come across a stainless exhaust manifold, although it's not surprising if only 150 were made. Regarding the crowned cam, after searching through various books and manuals, I found some information about it, but it didn't significantly impact wear or longevity. The process of cam replacement is similar for most large cams, with the exception of some IV models due to lobe lift and the use of different pistons/valve reliefs. In retrospect, the idea of the crowned cam was flawed as it caused increased wear on a specific area of the cam lobe, with the mistaken belief that it would provide better lubrication. Truck enthusiasts may find this information valuable for their next project.
Keep pushing ahead, I am absorbing all of this valuable information and wisdom!
It is unfortunate that despite our desire to learn more, individuals like T/S, RZ, and Stan have a wealth of knowledge beyond our reach. However, it is refreshing to delve into these discussions. Many thanks to these individuals for sharing their experiences.
It's amazing how much wisdom guys like T/S, RZ, and Stan have, as they seem to have forgotten more than we could ever hope to learn. Nonetheless, we enjoy reading their insights in these threads. Thank you for sharing your stories, guys! I must admit, I am constantly learning new things every day. Although, it does sometimes overshadow the knowledge I already have.
I have a feeling you give that same advice to every up-and-coming mechanic out there.
John C. commented that he often gives words of humility to young mechanics. This approach helps prevent them from developing an arrogant "I know everything" attitude. An unfortunate encounter John had was with a student halfway through a 2-year automotive course at a community college. Despite his education, the student lacked basic mechanical skills and wasted his tuition. He mistakenly believed his education made him smarter than experienced professionals like John. It's a reminder that practical knowledge and hands-on experience are invaluable in the field of automotive repair.
Every time someone notices a red spot or bump on my bald head, they always joke that I must have bumped it. I like to respond with, "Those are my knowledge knots from my last job." I make it a point to learn something new every day, starting as soon as I wake up.Visit the Truck Shop to unleash your inner learner!
One popular saying is, "If you're not constantly improving, you're actually declining." This phrase emphasizes the importance of continual growth and development.
Many members of my team often remark on my intelligence and problem-solving skills, jokingly calling me a genius. However, I simply attribute my abilities to the fact that I have had to repeatedly tackle tasks on my own due to financial limitations. I have learned through trial and error, and have always been self-reliant when it comes to fixing things.
Growing up, I never had the luxury of hiring someone to fix things for me. Instead, I had to rely on my own skills and resourcefulness. My crew often comments on how smart they think I am, but the truth is, I've had to learn through trial and error. I've only had to take equipment in for repairs a handful of times in 25 years, including an excavator rotec, a dozer transmission, a Detroit 6n-71 rebuild, and a couple of engine swaps. These repairs were only done in a shop when it was absolutely necessary, as we couldn't afford to stop working. Looking back, I realize how fortunate I was to have learned how to fix things myself, even though it was frustrating at times.
At the Truck Shop, I often get teased when someone spots a red spot or bump on my bald head, with others joking that it looks like I bumped my head. I playfully respond that those are my "knowledge knots" from the last job. It seems like I'm always learning something new as soon as I wake up each day. Reflecting on it, I realize that most of these "knowledge knots" were actually imparted by others when I was young and arrogant, eager to learn from them.
I have a knack for spotting sharp objects and cutting wire ties at precise angles with my intuition. I often find myself wondering who is responsible for leaving them there in the first place. - Truck Shop
The age-old tool of torture known as a zip tie with an angle cut!
The Truck Shop mechanic mentioned his knack for spotting sharp objects or wire ties with his head, often questioning who placed them there. He shared a humorous anecdote about accidentally head-butting a concrete wall while helping his wife store away patio furniture for the winter. Reflecting on the incident, he humorously admitted that he should have declined his wife's offer to help, as then he would have had no one but himself to blame for any injuries.
Working alone in the shop for the past few years has its downsides, like accidentally finding sharp objects or wire ties with my head. In those moments, I couldn't help but wonder who was responsible for leaving them there. Despite the occasional mishaps, I take pride in my ability to identify and address these hazards effectively.
Although old-fashioned, an oil-filled pushrod is prone to bending or end cap failure over time. If not addressed promptly, this can result in the follower slapping against the camshaft. While I haven't seen any cases where this caused significant damage, a few instances have resulted in roller, pin, or rocker damage within the cam box.
When it comes to pushrods, it's important to keep an eye out for potential issues. While oil-filled pushrods may seem old school, they can eventually bend or experience end cap failure, leading to issues like follower slapping the cam. It's recommended to regularly check pushrods by performing a tap test - simply tap them on a hard surface to distinguish oil-filled ones based on the dull thud. Additionally, give them a tug and twist on the ends to check for any looseness that may indicate damage. This simple maintenance routine can help prevent costly damages to your engine components.
There was still a possibility of a failure occurring. We referred to it as "ringslipping," where the item could slip out of one's grasp and fall to the ground, possibly onto a vise, hammer head, or even the shop floor if it was sufficiently clean.
DMiller mentioned that while old school, an oil-filled pushrod will eventually either bend or experience end cap failure. If left unattended for too long, this can cause the follower to slap against the cam, potentially leading to damage in the cam box roller, pin, or rocker. The solution, as suggested by Cummins, is to drill a 1/16" pushrod oil drain hole. It is important to pay attention to the inject pushrod, as they can be used as hydraulic jack handles. Hallback's cam failure seems to have been caused by a mechanic's incorrect inject adjustment procedure. In my opinion, 75% of cam lobe failures are a result of improperly done inject and valve adjustments. It is crucial to follow the proper procedure when torquing the Injector Plunger to set Pre-Load, ensuring Injector Plunger to Cup contact. The use of VS accessory drive pulley timing marks is recommended. Older methods of torquing injectors involved using a short thick blade screwdriver or guessing the torque. Nowadays, it is recommended to use in/lb torque wrenches, such as beam, dial, or clicker types. Clicker types are preferable as they make it easier to adjust all injectors equally. It is also important to pay attention to torquing Rocker Adjustment Screw Locknuts, as over-torquing them can affect inject adjustment or valve clearance. Using a Snap-on type Cummins torque wrench adapter is advised for this. For accurate injector adjustment, measuring the injector's plunger travel at 19deg BTDC for each cylinder is necessary. This helps ensure the fuel is injected properly. Altering the static injection timing can also help prolong the camshaft's service life. Fast Timing is considered advanced and requires higher mechanical-hydraulic pressure, while Slow Timing is considered retarded and requires lower pressure. Cylinder pressure is higher at retarded timing, so it is important to use the correct injector cups and ensure the piston's crown-bowl is at the right distance from TDC. Paying attention to these details can help avoid issues like shortened engine life and excessive smoke.
When it comes to oil-filled push rods, it is crucial to avoid cutting them with a torch or chop saw. I vividly remember being shown images during a training session at a Cummins school, showcasing the dangerous consequences of cutting an oil-filled push rod. The oil flash ignited, causing the push rod to burst and resulting in severe burns to the individual's hand. Avoiding such practices is essential for preventing accidents and injuries in the workplace.
I rarely come across oil-filled pushrods and typically use a hand hacksaw or die grinder with a cutoff wheel to repurpose them. If the socket is loose, it should be removed, cleaned, and re-brazed. For California on-highway usage with later engines (not NH200 or earlier models with single-double disc fuel pumps), it is recommended to discard the compression release control shaft and exhaust pushrods. The control shaft is softer than the pushrod bonnet and can shave away steel, leading to oil particle contamination. Additionally, bored drivers may misuse the compression release to show off, which can cause damage.
Petepilot undertook a DIY project with a Magnum A400 engine, managing to achieve over 435 horsepower from a supercharged engine that lasted for 162,000 miles. Unfortunately, after selling the truck, there was no further contact with the buyer to know how long the engine lasted. However, considering the average mileage of 74,000 miles per year for 24 years, it is estimated that the engine could have lasted over 1.75 million miles with proper maintenance. The use of upgraded parts such as 'retarded injector timing > 0.056”, low pressure PTD injectors > 181C, and low pressure PTG pump > 154psi' can help extend the engine and camshaft service life. An example of this is seen in the case of a 1972 KW#2-W900-NTC SC-350-13 speed with various modifications for regional hauling purposes. Regular maintenance intervals including oil and filter changes using Delo-series oils, along with injector and valve adjustments, were crucial in ensuring the longevity of the engine. Various in-frame services were conducted over the years to address issues like worn ring packs and cam lobe damage, ultimately upgrading the engine to Magnum 420-440Hp for improved performance. The story of KW#2 and its 39-year service life showcases the durability of the original engine, while other KWs had engine swaps to accommodate changing regulations. Important considerations like turbo-manifold pressure and exhaust temperature management were also highlighted to optimize engine performance and efficiency.
Proper deck height measurement is crucial, often more critical than precise timing. A common issue nowadays is the unavailability of on-road engines since 1992. Most engine blocks are not perfectly straight on the deck surface and suffer from erosion in the water ports and damage in the counter bores. In the past, 90 long blocks for diesel engines were assembled, with about 30 of them being complete builds. Injector timing on cylinders #1, 3, and 5 is adjusted using different gasket thicknesses to ensure even performance. Blocks may not be perfectly bored from the factory, necessitating adjustments during assembly. It's common for blocks to be decked multiple times, with each removal marked for reference. Injector settings should be done before adjusting valves, following a method that ensures precision. Repair sleeves in blocks are seen as a temporary fix by Cummins, indicating underlying issues with the engine. The 855 engine model had a major flaw related to bore spacing that was never addressed by Cummins, leading to ongoing gasket problems. Redesigning the block with more deck surface could have alleviated some of these issues. Overall, improvements were made in later models like the NT88, but the fundamental problem of bore spacing remained.
Hallback expressed optimism about resolving the issues with his favorite truck in the fleet, which he plans to keep as his personal hobby vehicle. Check out the attached photo for a closer look at this impressive vehicle.
In a recent discussion on StanRUS, the topic of the longevity of petepilot DIY Mag-435 engines was explored. Could these engines last up to 24 years with an average of 74,000 miles per year in regional hauls where drivers are paid hourly? One example highlighted the use of 'retarded injector timing > 0.056”, low pressure PTD injectors > 181C, and low pressure PTG pump > 154psi' to extend the engine and camshaft service life. This was seen in a specific Corona Clay New 1972 KW#2-W900-NTC SC-350-13 setup used for regional hauling in S. Cal. Regular maintenance intervals included oil and filter changes every 3,750 miles using Delo-series 3-30wt oil, switching to 8,000 miles Delo-series 3 15-40wt oil. The use of Chevron diesel from truck yard pumps was emphasized. Various maintenance procedures and adjustments were made over the years, with in-frame services in Aug 1977 and Dec 1985, and more updates made to the engines over time to improve performance and longevity. Even after 24 years of in-frame service, questions arose about the service records from the 85-year-old owner, Gerald D. Despite facing challenges like hot working conditions and personal losses during maintenance tasks, the KW#2 truck powered by the original engine stood out among others which had undergone engine swaps or upgrades due to various regulations. The importance of maintaining proper turbo-manifold pressure and exhaust temperatures for optimal engine performance was also highlighted in the discussion. Further information and updates on this topic may be shared in the future.
This discussion started with an issue on a BCIII follower/cam but somehow shifted to a rare small cam Magnum engine produced by Cummins in 1987. The discontinuation of the small cam engines led to the introduction of larger cam models. Despite this, it does not relate to Hallback's problem at the truck shop.
During my brief stint at Continental Engine Rebuilders, I encountered challenges with their insistence on utilizing upper bore sleeves to offset the high cost of the installation machine. This led to issues with coolant seepage in the engines we sent out, prompting me to leave after three months. Additionally, I faced difficulties convincing my colleagues to replace more parts in the RT9509s and RTO9513s we were working on, resulting in short-lived and poorly assembled engines. We primarily worked on SQHP and SQ100 third members, occasionally encountering Eaton and Corn Queen models. Despite concerns about riveted ring gears, some of my coworkers were hesitant to switch to bolting kits - a decision I disagreed with based on my experience showing that properly riveted rings outlasted bolted gears.
Truck Shop was puzzled by the sudden shift in conversation from addressing a problem with a BCIII follower/cam to discussing a small cam Magnum produced by Cummins only in 1987. The transition to big cams from small cams was due to specific reasons, but this discussion has no impact on Hallback's issue. The Magnum was introduced by Cummins to phase out small cam engine cores. DIY Magnums were developed before Cummins, where BC parts were used on small cam engines. The camshafts/roller followers from Cummins, whether small cam or big cam, play a role in Hallback's problem. Common failure modes include mistakes in adjustment procedures. To prolong cam service life, it is recommended to retard timing and use lower pressure, high-flow injectors with PT pumps. Retarded injector timing can also extend the service life of liner-ledge. The use of retarded timing has shown to increase torque and horsepower according to dyno tests and off-road equipment specifications. Crowned roller followers and cam lobes are not a frivolous idea but are based on sound engineering principles to prevent edge loading. The AR855 Stainless Pulsed Manifold, designed by James J. Fueling and Garry Shidner, features a patented reverse flow flange design that improves mileage. Hallback's BCIII cyl-block, if manufactured after September 1987, has an increased upper deck thickness to accommodate LPF liners, a carryover design from KT-series engines. The advantages of LPF liners include increased liner press fit, better support in the block, prevention of seeping head gaskets, extended liner-ledge service life, reduced cavitation corrosion-pitting, decreased ring blow-by, and prevention of head bolt thread cracking. Hopefully, Hallback can make connections and seek clarification from the individual responsible for repairing his retirement truck if he is not performing the engine repairs himself.
During my brief stint at Continental Engine Rebuilders, I found that they had a strong preference for installing upper bore sleeves, despite the high cost of the machinery required for the job. This was a common practice among engine machine shops, as it helped offset the expenses of operating expensive equipment. However, this sometimes led to coolant seeping issues that needed to be addressed. After three months of working there, I decided to move on due to the turnover rate among employees. It is typical for engine machine shops to adhere to OEM guidelines when machining cylinder block areas, such as liner ledges and coolant transfer holes. Unfortunately, the low pay and difficulty in retaining experienced machinists are ongoing challenges in the industry. I experienced this firsthand when I discovered an equipment manager receiving kickbacks for sending blocks out for repairs, resulting in significant costs for the company. In the case of the D346 V8 engine, repairs often exceeded $3,500. I made the decision to halt sending blocks out for repairs, following the motto of "if it's not broken, don't fix it." This experience shed light on some of the issues that plague the engine rebuilding industry.
I decided to resign due to my refusal to put my name on subpar work that was being mandated. Despite giving them ample opportunity to improve, it was evident that the toxic management philosophy of "Keeping employees angry to make them work harder" was not effective. This led to a disgruntled workforce that was not performing up to par.
It is a well-known fact that the timing code for a small cam Cummins engine was typically set at 36 degrees. The introduction of the Magnum was Cummins' solution to disposing of outdated equipment. The Magnum's timing was notably advanced to 56 degrees, making it a unique option among small cam engines. It is important to note the difference between small cam and big cam timing codes, as they correspond to different camshaft profiles. Many camshaft failures can be attributed to neglecting routine maintenance such as overhead adjustments and regular oil changes, as well as excessive fueling. With six years of experience in automotive machining, specializing in tasks like head decking, block machining, and line boring, I have firsthand knowledge of these issues. This concludes the discussion. Truck Shop.
DMiller explained that he made the decision to leave his job because he couldn't bear to put his name on subpar work that was forced upon him. Despite giving his employer the opportunity to make positive changes, they failed to do so. The overarching management philosophy of keeping employees angry to make them work harder did not yield the desired results, as it only resulted in a workforce of disgruntled employees who were not performing at their best. DMiller recalled a similar situation with a previous boss who would disrupt the workplace, prompting DMiller to intentionally provoke him in order to restore normalcy once he left. Interestingly, the boss was eventually demoted, and DMiller was offered his position, but he declined and instead assigned the boss to unpopular tasks which he continued to carry out. The irony of the situation was not lost on DMiller.
The Truck Shop made a point about the differences in timing codes between small cam and big cam Cummins engines. The standard timing code for a small cam was 36 degrees, while the Magnum timing was advanced to 56 degrees. This advancement was unique to the Magnum, as most small cams were not advanced to that extent. Comparing the two cam profiles reveals the importance of proper maintenance, such as running overheads, regular oil changes, and avoiding over fueling, to prevent camshaft failures. As someone with six years of experience in automotive machine work, including decking heads, blocks, and line boring, the Truck Shop emphasized the significance of these factors. The Magnum's advancement from 36 to 56 degrees was achieved using an offset cam key, though the specific number escapes memory.
I am a fan of these threads. Recently, a customer contacted me regarding issues with a 1979 Kenworth truck equipped with a big cam 290 engine. There seems to be a significant amount of blow by, leading me to believe there may be a cracked or damaged piston. Interestingly, we performed an "in frame" rebuild on this truck approximately 17 years ago. I have agreed to rebuild it once more to address the current issues. I am curious to inspect the condition of the camshaft. Only time will tell. The cost of a bottom end kit was $1,200.00. The old school 855 Cummins engines are renowned for their durability, almost on par with Detroit engines.
Not quite there yet! Just a little further to go!
User td25c expressed their appreciation for threads discussing old school 855 Cummins engines, stating that they rock almost as well as Detroit engines. Their comment suggested a preference for the nostalgic allure and performance of these classic Cummins engines.
In the world of truck engines, timing is a critical factor that can greatly impact performance. When the timing is advanced, it means that fuel is injected into the cylinder earlier during the compression stroke. On the other hand, when timing is retarded, fuel injection occurs closer to top dead center in the cylinder. The key to determining the timing lies in the push rod travel, with a higher numerical value indicating more retarded timing and a lower numerical value indicating faster timing. Adjusting injection timing is achieved by either advancing or retarding the cam follower action to the piston position. This manipulation is done by changing the orientation of the camshaft lobe to the cam follower using different camshaft gear keys. For Cummins engines like C, J, H, NH, NT, BC1, 2, 3, 4, Vs, and Ks, the standard position for the injector plunger is 19 degrees before top dead center, with a measurement of 0.2035 inches. It's crucial to note that for optimal engine performance, it's necessary to understand the nuances of timing adjustments. Whether through cam follower positioning or the use of gaskets and offset keys, getting the timing just right can make a world of difference in the power output of your engine. This attention to detail is what sets high-performance engines apart and ensures that they deliver top-notch results for truckers in need of reliable horsepower.
StanRUS explained in detail the importance of injection timing in Cummins engines. The timing of fuel injection, whether advanced or retarded, plays a crucial role in engine performance. Advanced timing involves injecting fuel earlier during the compression stroke, while retarded timing means fuel is injected closer to TDC in the cylinder. Adjustment of push rod travel determines the timing, with higher values indicating more retarded timing and lower values indicating faster timing. Changes in injection timing can be made by adjusting the cam follower action to the piston position. This is achieved by altering the camshaft lobe orientation using different camshaft gear keys. For Cummins engines like C, J, H, NH, NTs, BC1,2,3,4 Vs, and Ks, the standard injection timing is 19 degrees BTDC with a plunger position of 0.2035". It is noted that advanced timing involves moving the cam follower towards the inside of the engine, while retarded timing moves it away. In the past, it was common practice to use fewer gaskets or shims for retarded timing and not for advanced timing. The camshaft rotates opposite to the crank rotation, with a 335 engine requiring about 29 degrees of retardation with a straight-up key and no gaskets. This information, originating from various sources, is vital for maintaining optimal engine performance and efficiency.
In a recent discussion, RZucker shared insights on the timing of engine followers with dual indicators, highlighting the importance of gaskets and shims in adjusting timing. The cam's rotation opposite to the crank's movement affects the timing as well. For engines like the 335 with a straight key and no gaskets, timing can be approximately 29 degrees retarded. When it comes to advanced and retarded timing, it's essential to consider the engine's specifications. For instance, in-line 6 cylinder engines like the KT19 manual (18.7 liters) tend to have slower injection timing for higher HP engines, resulting in retarded timing. Models like the KTA700-C with 700Hp require specific adjustments using straight or off-set keys, while KT engines do not have follower boxes or gaskets. Engine timing adjustments for injector timing can be done by honing out the test cam gear for a single cylinder and correcting it based on timing charts. The process may involve heating the regular cam gear in an oven before installation. Engines like the KT series at Tier3 final are still used today. To focus the discussion, it may be beneficial to concentrate on Hallback's BC3. As we continue to learn and adapt, it's important to stay open to new information that may challenge our existing knowledge.
For on-highway use in Southern California, Hallback's BC3 cam & follower issue855s are considered obsolete. However, they are still utilized in off-road agricultural operations that are exempt from CARB registration requirements. One of our customers is currently operating 17 Case 8-tire agricultural tractors with 855s engines, despite the need for ongoing repairs.
The N14 engine is on the horizon as the latest addition to the lineup. The 855 and 1150 systems are quickly becoming obsolete, making way for newer models like the 3406, 3408, 1693 Cats, and the classic DD Two strokers. Upgrade now to stay ahead of the curve with these advanced technologies.
I haven't sold my D343 in the Skagit yet!
DMiller mentioned that the N14 system is the next evolution, leaving older models like the 855 and 1150 in the past. Farmers can rely on machines like the 3406, 3408, 1693 Cats, and the old DD Two strokers for their needs. However, there are restrictions in place for CARB-AG trucks and CARB-Construction Trucks until 2023. New smoke tests are being implemented by CARB for compliance. If you're a licensed general contractor, you are limited to 15k miles per year with CARB-Construction Trucks. The 77-359 1693 with minimal usage is considered a wise investment. Stay tuned on the latest developments on the official California government website. Truck enthusiasts may be disappointed as truck pulling contests are no longer allowed in California. The powerful 1150s with quad turbos in the unlimited class are capable of impressive performance. Tom Lindsay is highly regarded in the industry for his expertise with 1150s. In terms of engine upgrades, discussions about building a KTA700 with phase 8 industrial heads for on-highway use are ongoing. It's crucial to understand the specifications like BTU heat rejection per minute and injection timing from Cummins Engineers for optimal performance. Advanced or retarded fuel injection timing should not be confused in the process. As for Hallback's BC3, it appears that retirement may be on the horizon for the truck. Keep an eye on any updates related to this development. Visit the official ARB website for truck-related information: https://www.arb.ca.gov/msprog/truckstop/truckstop.htm
StanRUS revealed his intention to create a Truck sledge puller but lamented the ban on pulling contests in California. Could the reason behind the ban be the excessive black smoke emissions? It seems like these contests are not promoted due to this issue.
Birken Vogt wonders if pulling contests were outlawed due to excessive black smoke, leading to a lack of advertising. The annual festival in Temecula's Old Town featured tractor mud pit races until October 2013, emphasizing water conservation and the issue of black smoke. Jerry Deleo, owner of Corona Clay, leases practice-test tracks to Moto-Cross factory racing teams and Thompson Off Road Racing. However, regulatory issues prevented the decking of another hill for an off-road test track. With 1,300+ acres of Mining-Industrial property in Dawson Canyon, potential noise pollution from a new housing development nearby is a concern. Jerry's family, including son-in-law Jeff Ward, are involved in racing, but truck pulls present challenges due to black smoke concerns. Legalized Weed has impacted the availability of drivers and off-road operators able to pass drug tests. The business landscape has changed, with businesses feeling like they are now babysitting instead of operating. In California, lifestyle adjustments are required, such as dealing with constant traffic congestion. Despite the challenges, air quality has improved since 1990. Cheers or tears, it's all part of the journey.
California may not be known for tractor and truck pulls, but that doesn't mean they don't happen! Witness the power of a 220 Allis in action at the 2018 Indiana State Fair. Tractor and truck pulling, along with racing, are integral parts of American culture.
It appears that One State is on a conquest to dominate the world, which is not unexpected. If they continue at this rate, by 2023, there may be a significant decrease in farms, farming, road work, construction, and driving activities in California.
Interestingly, agriculture is often granted exemptions from various regulations and rules, showcasing the significant influence that the industry holds within the political landscape of the capitol.
Hallback posed the question: "Can this camshaft be salvaged or should I opt for a new one?" As discussed earlier, the best course of action is to replace the camshaft and followers. However, let me share a story with you all. I encountered a similar issue when I was installing a 290 Cummins camshaft in my 1973 White truck. One of the cam lobes appeared slightly questionable, but not yet showing signs of damage. Upon closer inspection, I found that the cam follower roller was in worse condition than the lobe. I decided to remove the cam follower assembly, lightly polished the cam lobe with emery cloth, and replaced the damaged roller. This experience of working on a Cummins engine in my driveway brought me joy and the truck served me well until retirement. If you start to see flaking on your camshaft, it may be time to consider a replacement.
td25c mentioned that they never experienced any issues with their truck, and it lasted until retirement. However, linear lines on the camshaft, as seen in the example photos, could indicate that maintenance practices need improvement. It is important to avoid dirt in the oil by using proper fill and refill methods, such as pre-filling oil filters and avoiding the use of galvanized containers. According to service manuals, Cummins engines are okay to use in this manner, whereas Cat engines are not recommended by engineers. Cummins' Biggest Cam Road Trucks, the K-series 1150s, were among the most powerful engines ever installed in US trucks from 1976 onwards. These engines, such as the KTA600 and KTTAC-HVT 750Hp, could be adjusted for even higher horsepower and torque levels. The Pete 379 glider Heavy Haul is an example of a truck that benefitted from these powerful engines, achieving impressive performance without the need for extra modifications to the frame rails. In Australia, Ks electronic update QSK19 is being utilized for pulling 140T Road Trains, while Truck Puller K19 Modified engines are reaching approximately 4,000Hp at 4,000Rpm. It is clear that proper maintenance and performance enhancements can significantly improve the longevity and power of trucks like these.
StanRUS pointed out that linear markings on the camshaft, as shown in the example photos, could indicate a need for improved maintenance practices. These lines can result from dirt in the oil, which may be caused by using galvanized 1-gallon cans during refills. It's always a good reminder that there is always room for improvement, as StanRUS often jokes with his wife. He is also curious to see how his friend's camshaft in the 1979 KW Big Cam 290 looks like and will find out once it is dropped off in a few weeks. The quest for better maintenance practices never ends!
td25c inquired about inspecting the camshaft in a 1979 KW big cam 290. It's worth noting that BC 290s typically don't cause excessive wear on cams. It would be great to capture some images for reference. For those creating YouTube videos, ensuring proper procedures are followed is crucial. For instance, when torquing head bolts, having a helper gripping the torque wrench correctly is essential. It's important to use the right specifications, such as 285lb/ft final torque for NTC-855 BC engines. When performing engine overhauls, positioning the engine for optimal leverage, like using body weight for torquing mains, rods, and head bolts, can make the process easier and more effective.
According to a StanRUS comment, BC 290 camshafts are known for not causing excessive wear. Although it has been 18 years since the last inspection, the cam appears to be in good condition. The engine is showing signs of a possible piston failure with significant blow-by but no knocking. It is suggested to open it up to confirm the problem. Stay tuned for future updates as we will share pictures of our findings. You never know what you'll discover until you investigate further!
In a discussion on camshaft stress in BC 290 engines, StanRUS pointed out that taking photos during procedures can be helpful for creating instructional videos. For example, when torquing head bolts like the NTC-855 BC @ 285lb/ft, it is important to ensure proper techniques are used. This includes having a helper grip the torque wrench correctly, especially for engines like the BC4 with longer head bolts. During engine overhauls, it is advised to position the engine for optimal torque application, using body weight for added pressure when torquing main components. It is crucial to avoid any mistakes, such as incorrectly gripping the torque wrench, to prevent potential damage.
StanRUS mentioned that BC 290 engines were surprisingly gentle on camshafts. He shared a few pictures showing that the camshaft appeared to be in good condition, while the pistons were not so lucky. With a laugh, he revealed that they had to replace the pistons, sleeves, and bearings in the bottom end of the engine. They also installed a new turbo, injectors, and radiator core on the top side. Thanks to these improvements, the 1979 KW truck is now back on the road and running smoothly.
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Answer: 1. Can a damaged camshaft be salvaged, or is replacement necessary? - It depends on the extent of the damage. Minor damage can sometimes be repaired, but severe damage may require replacement for optimal performance.
Answer: - Signs of damage may include unusual noises, rough idling, or poor engine performance. A thorough inspection by a mechanic is recommended to diagnose the issue accurately.
Answer: - Driving with damaged components can lead to further mechanical issues, reduced engine efficiency, and even engine failure. It's crucial to address such issues promptly to prevent costly repairs down the line.
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