Camming a 350 small block engine, also known as decking or milling, involves resurfacing the cylinder heads to improve compression and performance. This process is crucial for high-performance engines, especially those with increased boost pressure or nitrous oxide. Here's a comprehensive guide on how to cam a 350 small block, ensuring optimal results and enhanced engine output.
Before we dive into the process, it's essential to understand that camming a 350 small block is a delicate task that requires precision and expertise. It's recommended to have a basic understanding of engine mechanics and access to specialized tools. If you're unsure about any step, consult a professional mechanic or engine builder.
Preparation and Planning
Preparation is key to a successful cam job. Start by gathering all necessary tools and equipment. You'll need a cam grinder, a dial indicator, a micrometer, a camshaft, and various wrenches and sockets. Also, ensure you have the correct camshaft for your specific engine and intended performance goals.
Next, decide on the desired camshaft specifications. The camshaft's lobe separation angle, lift, and duration significantly impact engine performance. Consult with an engine builder or use specialized software to determine the optimal camshaft for your application.
Removing the Cylinder Heads
Before camming, you must remove the cylinder heads from the engine. Start by disconnecting the spark plug wires and removing the spark plugs. Then, use a socket wrench to loosen and remove the cylinder head bolts in a specific pattern to prevent warping.
Once the bolts are removed, carefully lift the cylinder heads off the engine block. Be cautious not to damage the head gaskets or other components. After removing the heads, clean them thoroughly to remove any debris or residue.
Inspecting the Cylinder Heads
Inspect the cylinder heads for any signs of wear, cracks, or damage. If necessary, perform a valve job to ensure proper valve-to-seat contact and minimize leakage. Additionally, check the head gaskets for any issues and replace them if required.
Measure the existing deck height using a micrometer. This measurement will help determine the amount of material to remove during the camming process. Record the deck height for both cylinder heads, as they may differ slightly due to manufacturing tolerances.
Camming the Cylinder Heads
Place the cylinder heads on the cam grinder, ensuring they are securely fastened and level. Set the grinder to the desired camshaft specifications, taking into account the measured deck height and the amount of material to be removed.
Slowly and carefully grind the cylinder heads, monitoring the progress with a dial indicator. Remove the specified amount of material evenly across the entire surface of the heads. Be cautious not to over-grind or create an uneven surface, as this can lead to poor compression and reduced performance.
Installing the Camshaft
Once the cylinder heads have been cammed, install the new camshaft. Begin by removing the old camshaft and its associated components, such as the camshaft bearings and seals. Inspect these components for wear and replace them if necessary.
Install the new camshaft, ensuring it is properly aligned with the crankshaft and valve train. Lubricate the camshaft lobes and bearings with engine oil to minimize wear and facilitate smooth operation.
Adjusting the Valve Lash
After installing the camshaft, adjust the valve lash to ensure proper clearance between the valve lifters and the camshaft lobes. Use a feeler gauge to measure the valve lash and make any necessary adjustments to the valve adjusters or rocker arms.
It's crucial to achieve the correct valve lash, as improper clearance can lead to excessive valve train wear, reduced performance, or even engine failure. Consult your engine's specifications or an engine builder for the recommended valve lash settings.
Reinstalling the Cylinder Heads
Reinstall the cammed cylinder heads onto the engine block, ensuring they are properly aligned and sealed with new head gaskets. Tighten the head bolts in a specific pattern to prevent warping and ensure a proper seal.
Torque the head bolts to the manufacturer's recommended specifications, using a torque wrench to achieve the correct tension. This step is crucial for maintaining proper compression and preventing head gasket failure.
After reinstalling the cylinder heads, reconnect the spark plug wires and reinstall any removed components, such as the intake manifold and valve covers. Perform a leak-down test to ensure proper sealing and compression, and then start the engine to verify its operation.
Camming a 350 small block engine can significantly enhance its performance and output. However, it's essential to approach this process with care and precision to achieve the best results. By following this comprehensive guide and consulting with a professional when needed, you can successfully cam your 350 small block and enjoy improved engine performance.