Frequently Asked Questions (FAQs)
1. What do push rod tubes do?
Push rod tubes are tubes made of stainless steel or cast iron that connect the camshaft tappet to the rocker arm in an engine. Their main function is to transfer motion from the cam lobe to the valve, and to facilitate the flow of lubricating oil to and from the rocker arm.
2. What is the strongest pushrod material?
S-7 tool steel is considered the strongest pushrod material. It is an extremely dense material commonly used for producing chisels and hammers. The use of S-7 tool steel creates pushrods that are stiffer and stronger, making them the top choice for high-performance applications.
Yes, push rod length can indeed affect performance. If the pushrod is too short, it can create valve lash, which can lead to excess valvetrain noise or even component failure. It is crucial to ensure the correct push rod length to optimize the performance and longevity of the engine.
4. Why are pushrod engines still used?
Pushrod engines are still popular for engine swaps due to their compact size. They have a smaller overall engine size compared to engines with overhead cams, making them easier to fit into tight spaces. This compactness makes pushrod engines a preferred choice for certain applications.
5. Why did Ford stop making pushrod engines?
Fuel efficiency was one of the main reasons why Ford stopped producing pushrod engines for their mass-market vehicles. The pushrod V8 engines had been in production since the 1930s, but Ford discontinued them over 20 years ago, with the exception of the 6.7-liter Power Stroke diesel motor.
6. Why can't pushrod engines rev high?
Most pushrod engines have a design with two valves per cylinder. This limits the engine's ability to take in enough air at higher RPMs, causing it to become starved for air. Without additional valves, pushrod engines are not able to rev as high as engines with more complex valve designs.
7. What happens if my pushrods are too long?
If pushrods are too long, the rocker tip can be positioned too far outboard, potentially causing the roller tip to travel off the edge of the valve tip. This misalignment can lead to issues with the valvetrain and affect engine performance. It is important to ensure the correct pushrod length for proper valve operation.
8. Is a shorter rod better than a longer rod?
In general, longer rods offer more leverage than shorter rods. This leverage is particularly important during the hook-set in fishing, where a longer rod can move more line quickly. Additionally, heavier action rods, which are typically longer, flex less and lose less energy compared to softer rods.
9. Do push rods wear out?
Push rods can wear out over time, especially if they are subjected to excessive heat. If push rods start to turn blue from heat, it is a sign that they need to be replaced. However, in short track oval racing, pushrods can be used for several seasons as long as they are not bent and show no signs of wear.
10. Can push rods be replaced?
Yes, push rods can be replaced. In a standard V8 engine with hydraulic lifters, the process involves removing the valve cover, removing the lifters, and then replacing the push rods. A qualified mechanic can typically complete this task within a couple of hours, depending on any additional accessories that may need to be removed.
