6 Advantages of the Cam in Block/Pushrod Engine
1. Low Hood Height
The hood of the C7 Corvette, and even the C4, C5 and C6, is as low as some rear engine cars. This is thanks to there being no cams hanging out on top of the cylinder heads. In fact, the LS motor is so compact it can deliver more than 500hp from a 28" cube package. If not for the cam being down in the empty space between the cylinder banks, and the pushrods, there is no way the Corvette could have a hood line lower than that of a Porsche 911.
2. Light Weight, Low Weight
Another reason the LS motors get swapped into a lot of other vehicles, and how the Corvette has such good weight distribution, is the weight of the motor. Even the cast iron LS truck motors weight less than 600lbs, with all the accessories bolted to them. An aluminum block 6.2 liter LS motor in the Corvette is less than 500lbs. The DOHC BMW M62 motor weighs that much, without the charging system, power steering pump, AC compressor, etc. All the heavy steel parts of the LS motor are much lower in the car as well, because there aren't four iron cams at the very top of the motor, nor a mile long timing chain. As pictured, including the heavy T56 manual 6 speed, the LS motor is just 609lbs.
3. Less Moving Parts
Part of the reason the LS motor is so light is because it has fewer moving parts. With less valves, less springs, less cams, and the like, there is just less to go wrong as well. If you aren't into European luxury cars, you may not have heard about the cam chain issue with the Audi V6, but some of them suffered catastrophic failure; and that motor features cam chains on the front and the back side of the motor!
4. Lower Price
A new 5.0 liter Ford Coyote crate motor retails for nearly $8,000, while you can buy a GM built LS3 motor for just $6,500. Both motors make nearly the same power, too, with the Coyote making five more HP but at the expense of low end torque. The price can be lower because there are fewer parts to assemble and fewer surfaces to machine, so production is faster and there is less labor involved.
5. Narrow "Shoulders"
It isn't that big of an issue with the Corvette, but one of the reason engine swappers love the LS is the narrowness of the motor. The lack of cams on top of the cylinder heads lets it tuck into the space you'd only expect to find a narrow angle V6 or L motor. The narrower motor allows the Corvette more room for important chassis parts in the front end, and also contributes to the lower hood line, and lower center of gravity, by allowing the motor to sit lower in the frame.
6. Easier Maintenance
The smaller size and less complexity means more room to work, and less in the way when you need to do something like change spark plugs. Plus, if you are building a bigger, badder motor with a hot cam, aftermarket heads, and more compression, you'll find it is much easier to do yourself with this old school design. As long as the shape of the ports is designed for modern flow and the combustion chambers for efficient flame front travel, there is no advantage in OHC vs. cam in block until you get up above 5,000 rpm, and even then not much until you get even higher.
If you have issues that need addressing with your LS powered Corvette, or even an older model, check out all our articles found in this helpful How-To section.