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Does flooding have an effect on compression readings?

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Old 01-12-05, 07:35 PM
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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?
Old 01-12-05, 07:42 PM
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Absolutely... why do you think flodded cars dont start? No compression.
Old 01-12-05, 07:53 PM
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thanks
Old 01-12-05, 09:21 PM
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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
Old 01-13-05, 12:53 AM
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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
Old 01-13-05, 01:57 AM
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flooding isnt going to drop your compression numbers by 75psi...

Last edited by jacobcartmill; 01-13-05 at 01:59 AM.
Old 01-13-05, 05:13 AM
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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?
Old 01-13-05, 05:34 AM
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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...
Old 01-13-05, 02:35 PM
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thank you. see my above post.
Old 01-13-05, 07:08 PM
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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.
Old 01-13-05, 11:28 PM
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the original engine in my 91 NA blew when i was STARTING the car on a cold night after work.
Old 01-14-05, 01:11 AM
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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.
Old 01-14-05, 02:31 AM
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dude, come on. 17psi? that is one ****** vicious flooding...

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

Last edited by jacobcartmill; 01-14-05 at 02:41 AM.
Old 01-14-05, 06:15 PM
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it was flooded after all...did the atf trick and it runs perfect again. thanks for the replies
Old 01-14-05, 07:33 PM
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Old 01-14-05, 08:48 PM
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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
Old 01-14-05, 09:24 PM
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http://xtronics.com/reference/convert.htm
Old 01-14-05, 10:25 PM
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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.
Old 01-14-05, 11:09 PM
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1 kg/cm^2 is 14.22 psi
Old 01-14-05, 11:32 PM
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1 bar = 14.5psi
1 kg/cm^2 = 14.2psi


1 atm = 100kPa = 14.7psi


-Ted
Old 01-15-05, 12:08 AM
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I just heard that the price of rice in china has went up because of our findings in this thread.

Yay.
Old 01-15-05, 02:40 AM
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Old 01-15-05, 03:49 AM
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Okie, now that the poster has his engine running again....

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

JAmes
Old 01-15-05, 09:12 AM
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Old 01-17-05, 06:09 PM
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i got the same problem im running 20 Psi. Im have a nasty flood!!!!!!


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