[Steve C.]

Not here to advocate or dismiss running solid roller cams on the street, done so for over 20 years. However not long ago I had my second solid roller lifter failure with my current 505. Never on other engines. In short, Crower had no clue why and it has not been oil related or lack of spring pressure to control the valves, etc, etc.

Not long after the second failure I called Keven Crocie about a flow bench to test my cylinder heads for interest while they were off the engine. While on the phone I mentioned the solid roller lifter failure. Also mentioned it was the second time. So out of interest he started asking some questions about the failures and my engine. Now the topic turned to the spring pressure and the lifter failures. I told him I use a PAC spring rated at 240 lbs on the seat but on a Rimac bench checker they test as much as 260 lbs. Big mystery !

His opinion it was too much spring pressure for a street application. I explained to him about my UltraDyne MSP solid roller at the time with .3400" lobe lift and that it had a 30 intensity and 0.709" gross valve lift. His opinion I should work on a cam that would be less aggressive yet give me the results I desired. Net result from the conversation was to evaluate the situation further after we tore the engine down. I called Tim at Bullet Racing and talked with him. He actually agreed with Kevin. My new UltraDyne solid roller from Bullet has the same amount of intake duration at .050" but less lobe lift and able to run with less spring pressure, as low as 190 lbs seat pressure if desired.


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