It’s true, nothing lasts forever and all good things tend to have a cycle. In this instance, we’re talking about the lifespan of your cylinder head’s valvetrain. Obviously a lot of this is contingent on its environment; mild performance applications tend to last, whereas those pushed through strenuous conditions will undoubtedly require much more maintenance.
If you recall our 525ci big-block build (“Big-Inch Punch”, Dec. ’11) where we installed a set of Brodix BP BB-3 Xtra 380 heads, we’ve been throttling that motor at full tilt with 39 pounds of boost. Unlike most of our test mules, we’ve actually dropped this thing in between the wheelwells of a 3,500-pound chassis with factory-style suspension; the results: 7.48 at 193 mph on 275 drag radials!
As impressive (and scary) as that is, we also learned that big boost can really take a toll on valvesprings, in the form of spring fatigue. After a number of pulls on the engine dyno and 30-plus passes on the tarmac, we noticed the engine fluttering around 8,500 rpm; it felt as if the rpm limiter was kicking in.
Once we pulled the valve covers and checked the valvesprings, we found that the spring pressures were down significantly. On the big end, the springs were allowing the valves to move erratically, which is also the reason it wouldn’t rev past 8,500 rpm. The fix was only a matter of swapping out the springs, a straightforward job. However, we decided it was best to do a complete rebuild and make sure all of the components were still in tiptop shape.
To handle this job, we headed to A.R.E. Performance & Machine in Simi Valley, California, where Rocco Acerrio took us through the entire process. So whether you’re looking for a simple factory rebuild or a performance upgrade, the process is the same and this is how it’s done.