February 2011 - Performance Zone
CATS, BULLS & TANKS!
By Performance Specialist Bruce C. Mallinson
How many of you purchased the twin turbo engine from Cat, produced between 2004 and 2008, to stay away from the ISX Cummins and Detroit Series 60 EGR engines? For those of you who did, have you ever wondered why this newer twin turbo Cat doesn’t perform like the older single turbo Cats did? Were you puzzled as to why this engine, on average, loses a mile-per-gallon over the older single turbo engines? Were you disappointed to find that this Acert engine doesn’t perform any better than your buddy’s EGR ISX? Well, what I am about to tell you will make everything clear – the twin turbo Caterpillar is an EGR engine.
Ever wonder what the actuators on the intake valves of these Cat Acerts do? They open the intake valve during the exhaust stroke and allow the exhaust to enter the intake manifold. This is a simple and cleverly disguised EGR system – it’s just not as noticeable as the EGR systems in the Cummins and the Detroit engines because it is internal. If you remove the air inlet elbow to the head and look inside the head or intake manifold, you will see soot and carbon caked on the sides.
We are currently in the process of rebuilding a BXS Acert. When we started to take it apart, we found hardened carbon flakes and soot in the bottom of the oil pan. The carbon in all oil products transforms as it is heated – the more heat, the harder and more abrasive the carbon particles get. With enough heat and pressure, you can mix carbon with metals and make steel cutting tools or even diamond. Your engine is able to produce enough heat to harden carbon to the consistency of what you scrape off a BBQ grill in your backyard after a cookout. These hardened particles are reintroduced into the engine though the EGR system and eventually circulate through the oil system. These particles then clog the oil filter and start grinding away at whatever they come in contact with. It is no mystery why these systems are detrimental to the life and performance of the engine. So, to those of you who drank the Acert Kool-Aid, don’t worry, we can help. Give us a call!
Have you ever changed the Bull Gear on your Detroit 60 Series engine? The Bull Gear is the large gear in the front of the engine that is driven from the crankshaft gear. The Bull Gear turns the camshaft, the water pump, the air compressor, the power steering pump, the fuel pump and the accessory drive, which in turn drives the alternator and air conditioning compressor. As you can imagine, if the two roller bearings (which are about four inches in diameter and located in the Bull Gear) fail, your engine is wiped out. When this happens, the valves hit the pistons, all of the gears in the front of the engine are stripped and all of the items previously listed come to a grinding halt.
The rule of thumb, in regards to replacing the Bull Gear, is that if the engine has over 850,000 miles and is being rebuilt, the Bull Gear should be replaced. We have rebuilt many 60 Series Detroits in the chassis with one million plus miles and found the Bull Gear had not yet failed, but we still always replace them at that time. The cost for the Bull Gear is about $700 and it takes about 16 extra hours to replace it. But if your Detroit is nearing 850,000 miles, this is something you are going to want to do. Just like a crankshaft damper at 500,000 miles, replacing the Bull Gear when you’re getting a rebuild is cheap insurance. A bad crankshaft damper can also shorten the life of the Detroit’s Bull Gear. Those of you who have over 500,000 miles on your Series 60 and haven’t replaced the crankshaft damper, you better think twice – that new damper will eliminate the torsional vibrations from eating away at the bearings in the Bull Gear (among other things).
Do any of you older guys remember the Cummins VT-903 engine? Schneider was the largest user of this 903 cubic-inch engine, which only produced 320 hp for on-highway use and 430 hp for fire trucks. In 1983 and 1984, we raced on asphalt circle tracks and had 840 hp coming from an old VT-903. Now, what most of you don’t know is that the U.S. Army used this engine in the Bradley Tank and other military equipment under the designation “Big Cam VTA-STC 903” (which was rated at 660 hp). In this case, the “A” meant that it was aftercooled, and the “STC” stood for Step Timing Control. This engine is a V8, and it’s a bear!
We once raced against a red Kenworth with one of these VTA-STC 903 engines at Pocono Raceway Park and, on the front straightway, with our truck going around 122 mph, this Kenworth blew by us so fast it was embarrassing. This engine is capable of 1,200 hp, and I’ll bet that’s what that red Kenworth was producing. Well, we have one of these VTA-STC 903 engines, and it’s brand new (not rebuilt) – and it is for sale ($18,500). You can’t buy this engine from Cummins, and if you could, the cost would be over $125,000. If you are building a toy truck, a drag racing truck or a sled pulling truck, this just may be the engine you have been looking for. In its stock form, it turns 2,800 RPM – and the sound it makes through straight stacks is phenomenal. If you procrastinate on this one-of-a-kind engine, it will be gone. Call us!
Here’s one last reminder about our upcoming Owner Operator Snowmobile Conference on February 26-28 in Stanley, Idaho. We are staying at the Mountain Village Resort and the rooms are very reasonable. Call (208) 774-3661 to reserve your room, but you must tell them that you are with the Pittsburgh Power group. Snowmobile rentals are available from Williams Motor Sports, and their number is (208) 774-2229. Please don’t wait, because rooms are limited. If you have any other questions, call me at Pittsburgh Power in Saxonburg, PA at (724) 360-4080 or send an e-mail to bruce@pittsburghpower.com. I hope to see you in Idaho!