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-   -   Does flooding have an effect on compression readings? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/does-flooding-have-effect-compression-readings-385173/)

RX7 RAGE 01-12-05 07:35 PM

Does flooding have an effect on compression readings?
 
I took readings on my engine which might be flooded and I got very low readings...4.2 in the front and 1.2 in the rear...does flooding cause this? I moved the car from the driveway to the street and shut it off right away. It was running fine before this happened so I might have to use the atf trick or push start it to get it to start right?

Rxmfn7 01-12-05 07:42 PM

Absolutely... why do you think flodded cars dont start? No compression.

RX7 RAGE 01-12-05 07:53 PM

thanks

AlmostRice 01-12-05 09:21 PM

I did the same 3 weeks ago. Could not start it the next day. I left it for a week and used ATF. I used a syringe and put one squirt in each rotor. Started right away. Here are some instructions to fix it.

http://2ndgenrx7.freeservers.com/rp_unflood.html

RETed 01-13-05 12:53 AM

YES!
Dirty trick for used engine sales creeps is to pour ultra thick oil into the engine and then take a compression check.
It also helps if it's really cold!

Gas washes this oil away.
You make the connection. :)


-Ted

jacobcartmill 01-13-05 01:57 AM

flooding isnt going to drop your compression numbers by 75psi...

coldfire 01-13-05 05:13 AM

maybe he means a reading in BAR?

still, 1.2 bar is crazy low...could someone explain how exactly that works? i mean how flooding an engine lowers compression?

NZConvertible 01-13-05 05:34 AM

The oil on the chamber walls seals the compression in. Excess fuel washes away the oil, so the chambers are no longer sealed and can't build enough compression to start the engine.

4.2bar and 1.2bar would be 61psi and 17psi respectively, which sounds like a cracked apex seal on top of being flooded...

jacobcartmill 01-13-05 02:35 PM

thank you. see my above post.

RX7 RAGE 01-13-05 07:08 PM

ugh..cracked apex seal just from moving my car from the driveway to the street? is this possible? those readings were from a mazda rotary engine compression tester by the way.

jacobcartmill 01-13-05 11:28 PM

the original engine in my 91 NA blew when i was STARTING the car on a cold night after work.

RotaryResurrection 01-14-05 01:11 AM

You can flood a car to show no compression. Dump some oil or atf into the chambers and start it up. Expect smoke, hold the rpm's up a bit until it clears out. I bet it isn't blown or anything.

jacobcartmill 01-14-05 02:31 AM

dude, come on. 17psi? that is one fuckin vicious flooding...

just unflood that bitch. drag it around a parking lot with all 4 spark plugs out and egi fuse out.

RX7 RAGE 01-14-05 06:15 PM

it was flooded after all...did the atf trick and it runs perfect again. :) thanks for the replies

RotaryResurrection 01-14-05 07:33 PM

Damn I'm good ;)

to all the haters...

nanana na na na I told you so!

:rofl:

TII '87 01-14-05 08:48 PM


Originally Posted by RX7 RAGE
those readings were from a mazda rotary engine compression tester by the way.

Mazda rotary engine compression tester readings are in Kg/cm2, not in bars...

dunno if it's the same in the US, but in canada that's the way it's calculated

coldfire 01-14-05 09:24 PM

http://xtronics.com/reference/convert.htm

RotaryResurrection 01-14-05 10:25 PM

bar and kg/cm^2 is damn near the same thing...one is 14.7, one is 14.2 or so IIRC. using either one to calculate by, you won't be more than 5psi off on the other.

jacobcartmill 01-14-05 11:09 PM

1 kg/cm^2 is 14.22 psi

RETed 01-14-05 11:32 PM

1 bar = 14.5psi
1 kg/cm^2 = 14.2psi
:D

1 atm = 100kPa = 14.7psi


-Ted

RotaryResurrection 01-15-05 12:08 AM

I just heard that the price of rice in china has went up because of our findings in this thread.

Yay.

jacobcartmill 01-15-05 02:40 AM

yayyyy kevin landers yayyyy

Wankel7 01-15-05 03:49 AM

Okie, now that the poster has his engine running again....

He should do a compression check again to see what it is now!

JAmes

RotaryResurrection 01-15-05 09:12 AM

me = teh winnar!

theone81 01-17-05 06:09 PM

i got the same problem im running 20 Psi. Im have a nasty flood!!!!!!


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