Digital Compression Tester

Courtesy of "COsborne"

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This tester is great if you're by yourself and don't have someone to turn the key for you or you want to log your compression at certain intervals.



Things you'll need:



1. Data acquisition unit

available from www.dataq.com

P/N: DI-194RS

$24.95 plus tax & shipping; total $30.02



2. Pressure transducer

available fromwww.grainger.com

P/N: 1X742 @ $103.05 plus tax & shipping; total $117.04



3. Misc.

avaliable from Radio Shack

16-gauge 2-conductor wire with one red and one black jacket, battery clips, fuse holder & fuse, and shrink tubing assortment for about $30 +/-



4. Flex hose with connector from previous compression tester – free

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Still havin troubles coming up on a part for it but it does work and work well at that!

 

cool.

 

now that i think of it, that datalogging stuff is basically a ghetto lab scope...$30 LOL



i remember my boss paying out $8k for a lab scope just like 5 years ago!

 

i just happened to bump into this thread and may be able to be of help.



i log exhaust manifold pressure, that'd be between the exhaust port and the turbo of course.



i use a honeywell pressure sensor 0 to 5 volts. they are available 0 to 100 or 0 to 150 psi. i would think that it would be easy to rig it up to the spark plug boss and datalog it.



honeywell pressure sensor monolithic signal conditioned 4000PC series. i don't have the url but it should be easy to find. i bought the 2 i use for $40 on ebay so they probably are not expensive.



maybe i will rig one up........



howard coleman

 

Thanks for the tip!

 

Man, you guys are way behind the times. I did this a year ago. It's freakin' handy as Hell.



Seriously though, I'm really glad to see more people doing it. The damn pressure sensor is usually the stumbling block since I've never seen one for less than a Franklin.



Hey what do you think of this test? It was the rear chamber of a 12A with a major water seal failure.



I'm especially curious to hear what people have to say about the little hitch on each upslope.



Cheers

 

Here's #1 for a comparison.

 

not only for the compression tester, but you cna test all sorts of **** with that.



do you happen to know how many samples per second the datalogger takes?

 

The cheapie DATAQ unit will go to 240 for a single channel. The graphs turn out much more smooth.

 

ample