The rubber plugs vanish if you operate at high power settings for very long. They just barely last in a street engine. Some usually gone on each tear down. That is not the problem. The

plug style corner seal is not very strong. All are powdered metal and under great stress, like a detonation event will crack. I have never found a stock solid seal broken. I have found the plug style broken many times. Just order the early solid corner seal. Not an after market solid seal. Mazda makes the best pieces in most cases.

 

Chatter marks are from warn apex seal grooves, low spring pressure, overheated apex seals, low or no apex seal lubrication.

 

Failed compression "O" rings have been over heated. I have never used an aftermarket "O" ring but as an emergency for a one weekend engine I have used Teflon or Kapton insulated 18 gage aircraft electrical wire as an "O" ring along with a very small bead of silicone in the groove.

 

It is nearly impossible to get the water "O" ring to fail. (the outer black one).

 

Ran that engine all year since it was not leaking at all. I always use the stock "O" rings, and even reuse them many times. 99% of the sealing is just the clamping forces between the housing and the iron.

 

 Racing Beat says to use 32 pounds of torque on the case bolts in boosted engines. Also no split timing, and not more than 12 degrees of advance in ignition timing. I would suggest over-rich mixtures for racing and full throttle climb out from low altitudes. Keeps things much cooler. More apex seal lubrication (if premixing). And even with Richards top oil adaptor I would premix just a bit more oil. The distribution is just much better in a premix.

 

On street ported engines never turn them backwards unless you know that the builder radiused the bottom of the port to pick up the drooping trailing end of the side seals.

 

Lynn E. Hanover

 

 

 

 Concerning the corner seal rubber buttons it seems that they end up reverting back to carbon and

lose all elasticity (particularity under high heat) and become useless for their original purpose which 

was to give slightly increased compression at starter speeds...........I personally will use the solid

racing corner seals available from Mazda and other sources.................IMHO