Frequently Asked Questions (FAQs)
1. How much horsepower can cast pistons handle?
Cast pistons, specifically hypereutectic aluminum pistons, are best suited for engines with up to approximately 600-650 horsepower in normally aspirated applications.
2. Are cast pistons any good?
Cast pistons have their advantages, particularly in terms of price and weight. They are cheaper and lighter compared to forged pistons. However, they are not as strong as forged pistons. For big-horsepower, boosted, and high-RPM applications, forged pistons are typically the preferred choice due to their strength and durability.
3. What is better cast or forged pistons?
Forged pistons are superior in high-performance applications due to their strength and durability. Cast pistons, with their higher silicon content, are more brittle compared to forged pistons. While the silicon content provides lubricity and limits heat expansion, it also makes cast pistons more prone to breakage under extreme conditions.
4. What type of pistons are best for boost?
Dish pistons are commonly used in boosted applications that do not require high-lift camshafts or high compression ratios. Dish pistons are preferred in these scenarios due to their design and compatibility with the specific requirements of boosted engines.
5. What are the disadvantages of cast pistons?
The main disadvantages of cast pistons are their lower reliability and strength compared to forged pistons. Cast pistons have a porous structure, making them more vulnerable to damage when subjected to abuse. This is in contrast to forged pistons, which are heavier but offer higher performance and durability.
6. What is the max rpm for cast pistons?
To maintain the generally accepted principle of not exceeding a piston speed of 3,500 feet per minute, caution should be exercised above 6,000 rpm in engines with cast pistons. At 6,000 rpm, with a standard stroke, the piston speed is approximately 3,484 feet per minute.
7. What is the max speed of cast pistons?
The commonly accepted limit for cast pistons is around 3,500 feet per minute (fpm). Revving cast pistons at higher speeds, such as 7,000 rpm, can lead to damage, including knocking off the piston skirts. Forged pistons, on the other hand, can withstand higher speeds, typically up to 5,500 fpm and more, especially in short bursts like drag racing.
8. Are dished pistons better for boost?
Dished pistons are often the preferred choice for engineers in boosted applications. They present fewer problems and are well-suited for use in engines that do not require high-lift camshafts or high compression ratios, which are common in boosted setups.
