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.
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
|SEAT LOAD:||146 lbs at 1.800-inch|
|OPEN:||369 lbs at 1.222-inch|
|SPRING RATE:||386 LB/IN|