OversteerNo doubt many of you have heard the old saying, "Idle hands do the devil's work." I've never really had this problem-there always seems to be more than enough to do, and we'll leave the issue of whose work is being done for another time. But what, exactly, does it mean to have clean hands? We've got no saying for that one, as far as I know.
I went ahead and put a larger carb on the Monte, and my wife said it wouldn't get as good gas mileage. I agreed with her, but when I was only getting around 12 mpg before, who cares? This car is an absolute thrill to drive, and it's provided me and my kids with hours of family time, tinkering with the car on and off the dragstrip. I drive the car about four times a week and yes, it sucks gas. The trade-off is, what price do you put on entertainment and, more importantly, being able to spend time with the family? My 14-year-old daughter has fallen in love with cars and currently has a car that she wants to build up by the time she turns 16. My wife even came around when she went to cheer me on at the track and now shares my passion for drag racing.
So, to answer your question on fuel economy, who cares when you're having so much fun? What people should really be worried about is the cost of popcorn at the movies!Brian Van WinkleGreencastle, PA
For SpeedA friend of mine recently asked me if I could help his neighbor with his 4x4 truck, which was having some drivability problems. A few months back he had decided to replace his '74 Chevy truck's aging 350 with something more powerful. Armed with a good stack of parts catalogs he randomly ordered a new cam, intake manifold, ignition, 383 engine kit, carburetor, and exhaust system. By the time I learned about this, the new engine was already installed and had been running for a few days. As I walked up the driveway, my friend's neighbor had the truck idling and was looking under the hood. What especially caught my attention was how rich the exhaust fumes were. Once in gear it had very little low-speed power.
When I asked him about the parts he selected, he told me said he installed a big hydraulic cam with 240 degrees duration at 0.050 inch lift. Next he mentioned that before he bolted on the carburetor he took it apart to richen it up. As I looked under the hood, I noticed that most of the vacuum hoses appeared original and were dried out.
I explained that his engine was largely suffering from an assortment of improperly selected parts. This poor drivability was generally because the camshaft provided very low engine-idle vacuum, causing the engine to have sluggish power through the normal operating range (1,000-4,500 rpm). With matching performance parts and new vacuum hoses, his truck would gain power, have improved mileage, and idle correctly. I also mentioned that out of the box, most carburetors are tuned and designed to run optimally.
Today, the aftermarket is loaded with parts to transform almost any engine into a powerhouse. Finding the optimal combination of parts is relatively easy because many performance parts manufacturers have already dyno-tested a variety of combinations for different performance levels and offer them in kit form. This parts information is available on Web sites such as edelbrock.com or holley.com. Almost every month in CHP, we test many of these engine combinations largely for one reason: to answer questions about performance. These are great times to build engines. By asking questions before spending time and money, you'll find rewarding answers.
If You Build It, They Will ComeHave you ever wondered exactly how much power a particular combination of parts will produce on a Chevy V-8? If you plan on building your next engine with GM Performance Parts, you can easily find the answer by visiting gmperformanceparts.com and scrolling down to Build It. By following the prompts you can configure, compare, and test an engine on GM's virtual dyno. Just click on your favorite block, cylinder heads, camshaft, intake, and carburetor, and run the dyno numbers. Right now there are 350, 383, ZZ4, LS2, and 502 combos. More engines will follow. Soon, GM tells us, there will be about 15,000 combinations available for you to dyno-test from your computer. You'll even hear sound effects of an engine running on the dyno as the data is compiled. -BM