Proper Engine Building Techniques - A Lasting Impression

A good machine shop will use accurate measuring equipment like dial-bore gauges to ensure critical dimensions are correct. Expect to pay a little more at a shop that has quality equipment and takes their time with your work, but know that the end result is worth the extra upfront expense.

Indy saved us some time by clearancing the bottom of the cylinder bores for a stroker crankshaft and connecting rods...

... and notching the top of the cylinder bores for the large intake valves in their 426-1RA CNC ported cylinder heads.

If you're assembling the engine yourself, we suggest performing the work in a clean room, with the doors closed and minimum distractions. In addition to cleaning your engine parts, be sure your tools are clean as well. Dirt on tools can contaminate an engine, causing damage on initial startup.

How old is your torque wrench? Has it ever been left sitting with tension on the spring? Tools like torque wrenches and micrometers must be checked and recalibrated periodically to ensure accuracy. We suggest sending them back to the manufacturer, or you can do what we do and take them to your local aircraft maintenance facility. Aircraft mechanics are required to have these types of tools recalibrated each year, so they'll know where to send them and the cost is usually reasonable.

Since this engine is extremely high compression, the piston is very close to the cylinder head at top dead center. For this reason, piston-to-head clearance must be checked as well as piston-to-valve clearance. Instead of estimating the compressed thickness of the head gasket, we keep a used gasket on hand to measure the actual clearance.

For maximum combustion chamber seal, we're using Total Seal file-fit piston rings and copper head gaskets. With copper gaskets, the head is "O-ringed" which actually means a groove is cut around the combustion chamber surface of the head, and a piece of stainless steel aviation safety wire is pressed into the groove.

The block gets a groove as well, called a receiver groove, and when the head is torqued in place the copper gasket is forced into the groove for a great seal.

Copper gaskets require sealer around the water jacket holes, and are likely overkill for most street applications. In addition to copper head gaskets, Summit Racing Equipment also carries a full line of multi-layer steel (MLS) head gaskets for Mopar applications.

Valvetrain geometry is vitally important in a high-revving engine like ours, and we found Indy's rocker arm kit to be well-engineered, properly placing the tip of the rocker on the valve stem throughout the valve's lift cycle. Additionally, these rockers are strong, built for the rigors of high-lift roller camshafts and springs.

Indy provides restrictors for the oil galleys leading to the rocker arms, limiting oil to the top end and directing more of the oil pump's pressure and volume to the main and rod bearings where it's needed. This trick can be applied to most motors that utilize a roller valvetrain.

You may not be building a high-powered, all aluminum Hemi for your Mopar, but you can certainly apply the techniques and procedures we used to the engine you are building. By using quality parts, accurate machine work, and proper assembly techniques, your engine will be as durable as it is powerful, and will give you many years of good service.