A heritage of power in trucks, motorhomes, and boats.
By Tony Wiese, F178480
While in Buffalo, New York, at FMCA’s 70th International Convention this past July, I took the opportunity to test drive two different motorhomes built on GM Vortec 8100-powered foundations from Workhorse Custom Chassis. I also had the opportunity to tour the GM Powertrain Engine Plant in Tonawanda, New York, a suburb of Buffalo. The Chevy motorhome chassis may very well have been the most successful type A chassis for several decades, and Workhorse continues to build on that successful tradition.
My motorhome has a 454-cubic-inch-displacement (cid) big-block V-8 rated at 230 horsepower. In the December 1999 issue of Family Motor Coaching, I wrote an article about my installation of the Banks stainless tuned headers, big-bore stainless exhaust, and ram air intake. As part of the article, I also ran performance tests, achieving significantly positive results. When GM brought out the Vortec 8100 big-block V-8 engine, it incorporated many of those same great features that I had added to my engine, thereby increasing the performance of the 8100. In standard dress, the Vortec 8100 V-8 truck and motorhome engine produces 340 horsepower.
In the past, an increase in horsepower usually was accompanied by a decrease in reliability. Not in this case; that paradigm appears to have changed. Because of the competitiveness of the light truck market worldwide, quality has to be the top priority. From what I saw at the Tonawanda plant, GM has embraced that head-on. With each successive generation of big blocks, GM engineers have honed the tolerances tighter, have designed more durable engines, and have integrated quality and testing steps into the manufacturing process.
These subjects could spawn an infinite series of technical and in-depth articles: the history of the world’s largest engine plant, the history of GM big-block engines, the competitive marketplace and the history of the motorhome chassis, why high-volume sales in light trucks benefit motorhomes and boats, and so on. So buckle your seat belt and hold on to your hat as we pump up the power and enter the world of GM big-block engines.
The first coach I drove in Buffalo was a 35-foot Fleetwood Pace Arrow with 19.5-inch wheels, a 340-horsepower GM Vortec 8100 V-8 engine, and an Allison five-speed transmission. Loaded weight, according to the Fleetwood label in the coach, was just under 20,000 pounds. The coach handled fantastically, was peppy, had power, turned great, braked well, and was extremely quiet for a front-engine unit. (With the Vortec 8100 V-8 engine, the equal length air intakes and sealed engine top eliminate the loud whooshing sound you get when you put your foot into the throttle on your 454-cid V-8.)
The second coach I drove was a 39-foot Winnebago Chieftain, also with a loaded weight around 20,000 pounds, according to the Winnebago coach label. This chassis was equipped with 22.5-inch wheels “” the only difference “” and I liked the added control I felt with the bigger wheels. This unit also had pep and acceleration, and could easily pass slower vehicles. I ran it at 70 mph up a slight incline and still had plenty of throttle left.
In my opinion, the Workhorse gas chassis is giving diesels a run for their money in the 26- to 39-foot production coaches.
The GM Powertrain Tonawanda Engine Plant is the largest GM engine facility, producing 35 percent of GM’s engine volume worldwide. It is also the largest engine plant in the world, both in terms of size (3.1 million square feet) and volume. Since the Tonawanda Engine Plant was opened in 1938, it has produced more than 63.5 million engines. At its peak capacity on five assembly lines, 8,500 engines were produced per day, and the factory has repeatedly made 7,000 to 8,000 engines per day. Big blocks are another story, as they have always been market-sensitive, and production has ranged from 250 to 700 per day, with 275 being the current daily average.
The original Chevy big-block engine was the 409-cid V-8, followed by the 396-cid V-8, which debuted in 1964. The 396 was then followed by the 427-cid V-8, which was renowned for durability and power. The 427-cid truck engine was so successful that it was produced through 1990. Next came the 454-cid big-block engine, which was produced concurrently with the 427-cid V-8 for many years. The 454-cid V-8 is what ended up in the Chevy motorhome chassis, with tens of thousands of them on the road.
The 454-cid V-8 was so successful in trucks, boats, and motorhomes that production lasted 25 years. Production of the 454-cid V-8 and its bigger brother, the 502-cid V-8 “” which was developed strictly for marine use “” ended in 2000. Due to marine customer demand, the 8100, 454-cid, and 502-cid engines were all built concurrently for several years. With each successive generation of big blocks, however, GM honed the tolerances tighter and designed more durable engines.
As a personal example, take average oil consumption. I still have our 1987 Suburban, which I ordered with a 454-cid V-8 rated at 230 horsepower. I tend to keep things forever, and the Suburban is a reliable workhorse that still receives only dealer maintenance. Since the day we got it, it has always burned a quart of oil every 300 to 400 miles. Our 1991 motorhome, also equipped with a 230-horsepower 454-cid V-8, must have received a tighter engine, because it only burns a quart of oil every 700 to 800 miles. In comparison, the much tighter tolerances of the Vortec 8100 engine are evident in our team’s Super Vee Class raceboat (which has two of the high-performance prototype HP3 Vortec 8100 engines, rated at 550 horsepower each). With throttleman Nigel Hook hard on the throttles and banging the rev limiters at 5,250 rpm during all of last year’s race circuit, the boat did not burn any oil between oil changes. We typically change oil every two to three races, which equates to between 250 to 400 miles per oil change. We are producing almost twice as much horsepower as a stock engine, and we are running under racing conditions with a constant severe load at all times.
The quality steps that GM has integrated into the 8100 production line help translate the tighter engine design tolerances into actual form. With the help of the line employees, GM has streamlined the work process by adding automation and mechanical tools to both facilitate production and help to ensure quality assembly. GM also has added numerous test cycles for the engines as the assembly process proceeds, rather than one final test as was done years ago. By repeatedly testing components during the production process, quality is built in, and if there is a problem, it is much easier to diagnose and correct. To that end, each of the major assembly areas where testing takes place has a side loop for redo and then reintroduction back onto the assembly line.
At this writing, the Tonawanda plant employed approximately 3,000 people. Years back, more than twice that number of workers produced fewer engines. Tonawanda has a very skilled workforce, and great strides in productivity have been made to keep the plant competitive on a worldwide basis. Since Tonawanda is one of the primary GM engine facilities, it draws on talent internal to GM as reductions at other GM facilities occur. At the same time, GM is currently investing $800 million into three new engine lines for the Tonawanda plant. Not only is productivity up, but quality has become the prime focus to ensure satisfied customers.
In talking with a number of the supervisors and line employees, I found that they all seemed genuinely interested in their work and dedicated to building the best big block possible. Over the years, with an increase in quality and productivity, the Tonawanda plant has maintained a very competitive edge among GM’s engine plants worldwide.
Workhorse Custom Chassis, which acquired the Chevy motorhome chassis business in 1999 and expanded it, has been one of GM Powertrain’s largest original equipment manufacturer (OEM) customers for the big blocks. Mercury Marine is the other large OEM customer for big blocks.
Workhorse Custom Chassis has purchased between 10,000 and 12,000 big blocks per year from GM over the past couple of years and looks to go to around 16,000 for the 2004 model year. With the GM Tonawanda plant producing approximately 275 of the 8100 big blocks per day, even 16,000 engines is slightly more than 58 days of production. And Workhorse Custom Chassis is just one of many internal and external companies that use the 8100 engine.
With quality and test steps integrated into the 8100 production line, all customers get higher quality. Because of the intense worldwide competition in the light truck market, horsepower has increased, and so has durability. With annual production numbers of engines and drive components in the tens of thousands, hundreds of thousands, and even millions, motorhomers benefit from significantly lower costs. And we can all look forward to better and probably more powerful GM big block products in the coming years. Who knows? A 420-horsepower Vortec 8100 (already available in the marine market) with gobs of torque might be available for your next motorhome.