Originally Posted by Judge Ito' post='133093' date='Jan 11 2003, 06:48 PM

That is the whole problem with the aftermarket seals like Hurleys and Atkins. I have seen .0016 of metal expansion when the engine warms up under a load. If you don't make the seals a bit shorter,(even though is a 2 piece apex seal) the shorter piece of the apex seal will slip over the larger peace when the engine is under some serious temperature,(because of the metal expansion promblem) and create some blow by or leakage from one chamber into another.I have talk to many people that did what Hurley recommended. Not to clearance the seals and all I could say is many ,many people are not using Hurleys seals anymore. I took a 2piece 2mm Atkins apex seal and measured the seal, then I heated the seal with my acetylene torch, I had the apex seal turn cherry red and let the seal cool off and re-measured and I had an apex seal that was .0016 of an inch larger from side to side. If you have a rotor housing with a width of 80mm and start with an apex seal with 80mm your going to have problems. becuase this apex seals grow like Chia Pets under some temperature. Stock seals have a totally different hardening and do not grow like the after market ones do.

Originally Posted by Drago86' post='827950' date='Jul 11 2006, 11:59 PM

I have a huge problem with this. Having a 2 piece seal too long is what makes the assist piece stay below the main one, if you clearance the seal shorter then the rotor housing the assist piece will ride up and cause low compression.

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