I once found a link that had plans to build an electronic compression tester. I can't find it now does anyone no where to find the plans, Honest I did search.

thanks Dave

No plans needed. It's really not very hard at all once you have a sensor. Just look for one with an excitation voltage that's easy to deal with and a range not too far out there. 500 PSI isn't too much.



Use a Dataq box as the interface with an old laptop. Google 'em, I can't remember the model numbers off hand. More resolution than you'll ever need.



I'm using a sensor that allows me to use a 9V battery for excitation.



Cranking speed can be easily determined once you have the data by looking at the peaks.