New BMW 4 Series pistons are an important step in refreshing your BMW 4 Series engine and preparing it for more power. If you are doing a stock rebuild, OEM-style pistons will typically be fine and can actually function better than forged pistons under regular conditions, but upgrading to stronger units can be a wise choice considering your engine will be already be apart anyway. Since forged BMW 4 Series pistons are also lighter, they can help your engine rev more quickly. Spending a bit more now could save you a lot of headache and money compared to having an inferior piston fail.

Most BMW 4 Series pistons are available in both cast and forged configurations, with the latter being preferred for high-performance engine builds. Forged BMW 4 Series pistons are stronger, and generally lighter than OEM-style cast pistons, and are available in more configurations as well, including coated pistons that help reduce friction. The type of piston you choose should be based on your power goals, so things like compression ratio, bore diameter, desired powerband, and type of induction (forced vs. naturally aspirated) should be considered before making a final decision.

Q: How do you install pistons?
A: Pistons should be left to the pros because removal of your engine will be needed. The head will be taken off from the bottom block and internals will be replaced. Machine work will be done with specific tolerances achieved.

Q: What are pistons? Why buy pistons?
A: Pistons are part of your block assembly that are connected to the rods, and they compress the fuel/air mixture creating an explosion that drives the rising piston back down to start over rotation over again with a new charge of air and gas.

Q: Do pistons come in sets of 4?
A: Pistons are sold in sets or individually, depending on your vehicles motor. They are car specific and all pistons should be replaced at the same time during a rebuild.