Compression test numbers and math
 

Hi guys I tryed searching compression test threads and could not find what I'm looking for :spank:

I need to know how to do the math with my compression test numbers? :confused:
Or is there something for me to down load that I can plug my numbers into for a end result?

I have a felling I need a rebuild :rolleyes: and if thats the case this mt did not last any longer than my at did :nono:

Have a go with this link:

http://foxed.ca/foxed/index.php?page=rotarycalc

Let me know what you came up with plz.

Grtz

nice thats the tool i have to measure the compression

Thanks! I download that and run my numbers and post them up when I get home.

@!!narotordo PMed me his numbers and using the calculator this is what I got:

Original numbers:
F
060 057 059 @ 184 RPM
R
065 069 071 @ 191 RPM

Using the calculator (rounded):
F
82 79 81
R
85 89 91

Mazda's specs are:
Standard = 120psi @ 250rpm
Minimum = 98.6psi @ 250rpm

I know the calculator is useful for corrections, but wouldn't the numbers change if he was turning the engine quicker (closer to 250rpm).
I'm obviously no expert on compression testing ;)

Mazda had the specs up @ 250rpm, probably because that is the rev/min it should hit during the test. Of course numbers could better a bit by having a bit more rpm, having a slightly better seal and less pumping loss.

But these numbers are down by quite a bit, roughly corrected even down bout 40% from "healthy". The 50 rpm short will def. not make up for this percentage.

Don't know the mileage and way of use, but seems to me before all else fails or pops up as a "diagnostic problem" i would personally opt to make the engine healthy again, so basically a rebuild, def. new seals etc..

someone's engine is toast...

Let's get some Iannetti seals and rebuild it.

^Baller!

Yeah George its gone :(

Yep - looks like mine:

https://www.rx8club.com/picture.php?...ictureid=14565

^Dude! where did you get that cool looking chart? and how do you read that?

how about these numbers...(not mine)

26 21 24

191 rpm

Gil, didn't you use the "Godfathers" compression tester?

^Yes

did you then multiply by 1.039 and adjust for cranking speed?

How do you adjust for cranking speed? Gracias Jorge. Iknowyournotmexican.:rofl:

here ya go AJ http://virusakos.freevar.com/

whosaidIwasmexican?

The word "compression"comes from an old Greek word I assume... :yelrotflm

Gotta luv those those guys!

rotor #1: 7.5, 7.2, 7.4 at 239 RPM and rotor #2: 7.5, 8.0, 7.7 at 238 RPM

this is what i got from Tustin Mazda when i got my car back..are these good numbers for a compression test?

Those numbers are pretty decent if you ask me ...

SHHHHH ...

thats what im planning to do ... jesus how dare u ! u just told everybody !

Now I have to kill whoever knows my plan ... damn quite a lot of people to "finish" ... :eek:

Just stuff them with that big cheesburger!

decent as in my engine is in good shape?

Three someone's engines are toast...........The dealer will be busy today. Jedi, thanks to you and the others for coming on and giving the advise that you did. To be honest I forgot about the RPM correction.

No one, but gracia jorge so hispanic. lol gracias again.