Smart51s post on compression testers gave me the idea that it would be nice to have a cylinder leak down tester. There is a seller on ebay selling them at a reasonable price but still more than I would care to pay. Using bit I had lying around I figure I have enough to make one.

Being too lazy to design it myself I did a google first and came up with these

http://www.xs11.com/tips/misc/misc3.shtml

http://www.650motorcycles.com/LeakDownTester.html

I made a simple one for the pinto engine by removing the porcelain section and then fittted a long tyre valve (very tight fit) into the remanis of the plug. Screw this assembly into the relevant plug hole when that cylinder is on top dead centre compression fit a small 12v tyre inflator pump with lock on connector and pressurise cylinder. Then simply switch off, disconect and listen. to release pressure undo core with valve key and remove assembly when finnished.

Works a treat and it is in the locost spirit.

[Edited on 12/11/05 by jollygreengiant]