Roller rocker - Caution if you have Blue 1.3 : 1 Minisport rockers

[Drakman]

Hi Guys and Girls,

Just  a quick word of caution, if you are using these roller rockers.

These are my roller rockers, fitted new approximately 8,000 Klm's ago.  My engine has a Kent MD 276 cam with new followers and pushrods. My cylinder head had been skimmed 0.020" and when i rebuilt the engine i asked that the block and head just be made flat and shiny only, so probably a total of 0.030" off standard. The rocker geometry is not perfect but close.  I have C-AEA526 valve springs fitted (200lbs)  Valve clearance 0.016".  A bit tight perhaps?

 The following video and pics tell the story.

Interestingly only 3 arms are effected, so far!  both inlet and exhaust on number 4 cylinder and number 3 cylinder exhaust.

https://www.youtube.com/watch?v=7ic6CkylCyk&feature=youtu.be







As can be seen in the last photo the roller is below the level of the rocker arm, which is how i found the problem.  Trying to move the feeler gauge side to side, it wouldn't move because it hit the alloy of the arm.

My opinion only, is that the circliped (is that a word?) pins that hold the roller in place had enough clearance to make them easy to fit but too much for the constant up and down on the valve tip and that has allowed the pin hole to work itself oval.

MiniSport make a slightly  more expensive set of roller rockers, purple in colour, that use a pressed in pin that seem to be the ones to get.

My advice to anyone using these rockers, check them carefully!

Dave