Piecing together high-performance components can take time and patience but correctly measuring for clearances is just as, if not more, important. When it comes to the technicalities of engine building, the more you know the better off and more capable you'll be when choosing the right components. A less-than-adequate valvetrain can make or break your build-potentially leaving you stranded.
In an effort to clear the confusion on valvetrain assembly and we headed out to Quarter Mile Performance in Chatsworth, California, to see how the pros set up one properly. There we followed along in order to showcase for you, the reader, the correct methodology when assembling a set of cylinder heads for the street or strip. For this build, we've gotten hold of a set of iron GM big-block heads destined for the street. Fortunately, for us, the machining was all completed and they were ready for reassembly. Assuming you are either having your local speed shop do the assembly or you intend to assemble them yourself, having the know-how on what's going on can expedite the build. To prevent bent valves or broken valvesprings, properly checking and measuring will ensure your build is starting off correctly. Once the measuring is complete, it's only a matter of putting it all back together.
Generally speaking, most install heights are checked after a set of cylinder heads has bee
Michael Consolo headed up our reassembly of the cylinder heads and demonstrated the steps. We followed along as Consolo measured for the correct install height of the valvesprings, valve seal clearances, and tested for an accurate set of spring pressures. That's what is involved to turn the heads into a complete package. Now our big-block heads are ready for the street.
What We Did
Determined the correct install height
Some forethought can prevent valvetrain failure with these simple steps
||146 lbs at 1.800-inch
||369 lbs at 1.222-inch
For this assembly, we used a set of 2.19/1.88-inch intake/exhaust valves. Once fully lubed
Using an install height checker, Consolo slid the tool along with a 1.550-inch Comp steel
Using the same method, Consolo measured the exhaust valve install height; each came in at
Next, the springs were checked for strength and size. A set of Comp dual springs (PN 924-1
With the steel retainer attached to the valve using the 10-degree lock, a micrometer is us
Utilizing the intake (1.8005-inch) and exhaust (1.845-inch) valve install height measureme
After everything checks out, 1.500-inch spring cups are added to each intake, while the ex
While a professional Sunnen cylinder head machine was used for this application, a manual
A properly checked cylinder head should provide years of trouble-free service when it's me