I am in the market for some new pistons, I know that Endyn pistons have a generous valve relief, and that Wiseco makes the pistons for Endyn. So, is it safe to assume that the Wiseco's have the large valve relief to begin with?

 

While I do not have a definitive answer for you I will tell you this:

A friend of mine is running Endyn pistons in his VW engine, roughly 13-1 compression. He did numerous calculations before putting the engine together. He clayed the engine to make sure the clearences would be safe. He dry fitted the engine on more than one occasion. When he thought all was good he fired it up. Luckilly he was still a little concerned and upon inspection heard the little ticking noise of valve interference. He then had to take the engine out tear it back down and do some more modding. Now al is well but you can never be too sure of yourself!

 

The Wisecos I sold had valve reliefs that appeared to be just as deep as the JEs I now have. I like the look of the JEs more, but both companies make a very nice piston.