So I just finished my compression tester this past weekend. I haven't used it yet due to my lack of free time but i'll get to testing my 2 engines eventually. Its cost me $97 to build. $50 on a setra pressure transducer via Ebay. $30 for a dataq instruments data logger. $10 for a donor boinger compression tester. And finally $7 on odds and ends to connect the compression tester to the transducer as well as wires and batteries. All and all, i can't wait to play with it!!

 

Is this a how-to thread or a I have a new toy and you don't, thread?

 

Hopefully it will be a 'How To' so we all can build our own. Will this have some sort of a print out, or a simple digital log that can be printed later?

 

^^^^
some of you guys are so funny

 

Jon was working on making one of these too. I think there is a thread on nopistons about how to do it. Basically, you take a pressure transducer (200 psi or whatever) and connect to the datalogger. The presssure transducer puts out a voltage that relates to pressue. The datalogger connects to your laptop and you can plot the pressure as the engine is cranked. It is like the paper traced Mazda testers were you look at the different peaks to read the pressure off each face. You can look at the time between peaks to determine cranking RPM. I agree that we need a how-to for it on here.

I am designing one like the Mazda digital one where it displays the pressure for each face. It will probably a bit more expensive than this version (probably not much higher), but would be self-contained. No need for a laptop or anything.

Edit: Here is the thread on nopistons:

http://www.nopistons.com/forums/inde...ression+tester

 

Interesting project.

 

I made one about a year ago, with the help of an EE in Canada. The results were not spectacular. It worked, mind you, but it was complicated and in no way practical. Basically, it plotted CAS tooth angle against transducer voltage. It could data log or stream data to a computer. Anyway, the project dragged on (the EE was always flying around the world on consulting jobs) so I abandoned it and bought myself a real Mazda Compression Tester. Far, far more practical for everyday use in the shop.

 

How much was the mazda tester?