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|We used the MM 293 solid flat tappet camshaft from Comp along with their recommended springs, lifters and oil additive.|
|The Comp 2901-16 lifters have a small oil feed hole for direct lubrication of the lifter face.|
Bracket racers have been having a tough time lately with the durability of flat tappet camshafts. The EPA restrictions on additives for engine oil have led to a number of problems, as has a decline in the availability of high quality lifters. The net result of these changes has been an increase in engine failures due to the loss of one of more camshaft lobes. Fortunately, the aftermarket has been busy coming up with new solutions for the average engine builder. One of those solutions is the new nitrided surface treatment available from Comp Cams. Other potential solutions to the durability issue are direct oiling solid lifters, as well as new advances in valve springs and lubricants. In an effort to shed some light on this subject we gathered up a selection of these parts and put them to the test in our big-block dyno mule.
Our dyno engine was originally built for a budget minded bracket car, so it uses a factory 440 block. In order to keep the cylinder walls as thick as possible, the block was bored just 0.030 oversize to a final bore size of 4.350. This engine uses a 4.250 stroke crankshaft from 440Source and 6.800 long BB Chevy rods from SCAT. The 6.800 rods fit just fine in the tall 440 block even with the 4.250 stroke and they leave plenty of space for a conservative piston design. We were willing to run race gas in this engine so the pistons were ordered from Diamond Racing with a small 5cc dome. Final compression ratio is 12.5:1 with closed chamber Edelbrock heads.