Upgrading your engine for performance often leads to questions about necessary supporting components. One frequent query revolves around pushrod guide plates: are they essential? This article provides a detailed exploration to help you determine if your engine build requires them.
Pushrod guide plates are hardened steel plates that precisely align the pushrods as they travel between the lifters and the rocker arms. They are particularly crucial when using high-performance components or when altering the cylinder head geometry. But when are they truly needed?
Several factors influence the decision of whether or not to install pushrod guide plates. Let’s delve into these considerations.
One primary reason to consider guide plates is when upgrading to aftermarket cylinder heads. Aftermarket heads often feature relocated valve angles or larger diameter valves. These changes can cause the pushrods to rub against the cylinder head, leading to wear and potentially catastrophic engine failure. Guide plates ensure proper pushrod alignment, preventing this interference.
Alt text: Pushrod guide plates installed, demonstrating precise pushrod alignment and clearance from cylinder heads.
Another critical factor is the type of rocker arms you are using. Roller rocker arms, while beneficial for reducing friction and increasing valve lift, require precise pushrod alignment. The roller tip on the rocker arm needs to maintain consistent contact with the valve stem, and guide plates help achieve this. Conversely, if you are using stock rocker arms and maintaining the factory cylinder head configuration, guide plates may not be necessary.
High-performance camshafts with aggressive ramp rates and increased lift can also necessitate the use of pushrod guide plates. The increased valve lift and faster opening/closing rates place greater stress on the pushrods. Without proper alignment, the pushrods can flex or bend, leading to performance loss and potential engine damage.
Furthermore, if you are milling the cylinder heads or decking the block, you are altering the engine’s geometry. These modifications change the pushrod length and can affect their alignment. In such cases, installing guide plates and measuring for the correct pushrod length is crucial.
To determine if you need pushrod guide plates, carefully inspect your existing setup or planned build. Look for any signs of pushrod rub against the cylinder heads. Also, consider the factors mentioned above: aftermarket heads, roller rocker arms, aggressive camshafts, and altered engine geometry. If any of these apply, installing pushrod guide plates is highly recommended.
Keep in mind that installing pushrod guide plates often requires machining the cylinder heads to accept them. This usually involves enlarging the pushrod holes to provide adequate clearance. Consult with a qualified machinist to ensure the job is done correctly.
In conclusion, while not always necessary, pushrod guide plates are a vital component for many performance engine builds. By considering the factors outlined above and carefully evaluating your specific setup, you can make an informed decision that will protect your engine and optimize its performance. If in doubt, it’s always best to err on the side of caution and install them.
