She Who Must Be Obeyed [if you want to want to keep the model engineering budget at it's optimum level]. Anyone know anything about free piston engines? I've got someone here asking about them. I've found a few things on the web... http://www.ee.kth.se/php/modules/publications/reports/2005/IR-EE-EME_2005_003.pdf ...but I'm curious as to whether it's an old concept rehashed with some modern kit fitted to it. Yours, Rich (31; wife, just turned 29. Wife says I have the bald head of someone who who is aged 131.) On Wed, 21 Nov 2007, Patrick Coppens wrote: SWMBO" ???? what the h#&& is that? MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.