from the se-rx7.com mailing list:



Subject: Compression Meter

Hello,

My name is Dustin And I have a survey question to ask you guys. My company has developed a compression meter for rotary motors.
We have made single rotor, dual rotor, and three rotor meters. The meters can be switched to read in psi or bar and also tell you the rpm. They tell you the average, the highest peak, and the lowest peak value for each rotor face along with the difference between the two. If you could please email me in regards to intrest and if there is enough demand we can start production effective immediately. I am a proud RX-7 owner (90' Turbo II and several N/As) and know how much help this meter is in a shop, or a do it yourself environment.

The meter is digital. It reads many many times a second. It can be interfaced with a computer and results can be printed. Pricng should be about $600 +/- $100. It has more features and doesn't cost as much as the $1700 Mazda Unit I have seen on Mazdatrix. It also allows you to test all rotors at the same time off of the same spin so all readings are under the same conditions. Like I mentioned before it saves the peak and the low for each rotor face and the difference. It can be switched from bar to psi. And of coarse the average for each individual face.

Thanks,
Dustin Setayesh
Dustin_Ali@Yahoo.com

 

Could be usefull allowing you to monitor the condition of the engine, but if they are prohibatively expensive hard to justify...

 

Sounds reasonable to me. I like to tinker. It'd be a lot more useful than that diagnostic tester I bought some time ago. As far as being not cost effective, well just owning one of these cars is'nt the most cost effective thing a person can do. (just having fun with you asherwood, humor please).

 

For $5-700 I'd be interested. It would make a nice "loaner" tool to have in our local club...... Assuming it works correctly.

Has anyone gotten back to this guy at all?

Greg O.

 

Sent him an email with this thread's link. Hopefully he'll post some additional details here.

 

I just sent him an email as well. Something to the effect that I'd like to see a cheaper model with fewer bells and wistles. My logic is that you only use a compression gauge to get a relative number anyway. The rotor is either sealed or it isn't. A bad/blown seal is pretty obvious and it's not critical to compare front to rear rotors at the same time. Two reading can be taken and the same diagnosis made. I'd go $300 easy for something like that. That's what I'm thinking anyway. Maybe if we barraged their people with requests they'd build us something like that?

Chris

 

Id like to have one, beats the hell out of my regular piston tester and a digital camera played in slow mo I remember me buy something like this back about 4 years ago, it was called a SPL meter and I made 20X what I paid for it, by charging $5/car to check SPL...

 

I might be interested in a base model as well, if it were around the $300 range as c. Ludwig said. ITs pretty obvious to tell if an engine is blown or not, but some fairly accurate numbers that can indicate the life left in a used engine would be real nice. IT would need only read one rotor at a time, only in psi, one reading per face, adn thats about it. You dont need to read both rotors at once(this could actually lower the compression numbers if you think about it, which is why during a test you remove BOTH lower plugs...), and you dont need an rpm signal...you know if your battery is strong enough to turn the thing normally or not.

 

Sounds interesting. I'd like to see pics.

Not bad price compared to the Mazda tester, which I thought about buying at one point. It would probably be really useful in a shop.

From my personal experience, however, a boinger compression tester with the hose and gauge check valves (not release valve, of course) removed works very well. I usually use a momentary switch to turn on the starter, which allows me to be right there watching the gauge. It may not be as accurate as this meter, but I can tell where the peaks are within 5 psi. It's really not that hard. If you have a bad seal, this method will tell you.

I've done compression checks on all 8 of the 7's I've owned, as well as numerous friends & customers, using the boinger gauge. Works for me.

Ren