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Old 05-28-12, 06:43 PM
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NY rebuilt engine

i just rebuilt my rx8 engine... doped it in... and car dos not start...engine is flooded by now with all that fuel that went in

it has nice even pulse... but when i hooked up piston engine compression tester didn't get much of a readout -0psi

is this normal for fresh rebuilt engines ...all new seals,springs, bearings..........

here is the link to a video of engine pulsing without spark plugs

http://youtu.be/qJtqkvoVjO8
Old 05-29-12, 08:20 AM
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is the rebuild just bad or the seals need to brake in

nothing fell out of the engine or broke so everything is in place

apex seal look to be moving and no stuck

could stuck side seals be the problem

or the the housings that i reused

which didn't look to have much where on them
Old 06-10-12, 04:06 PM
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after adding bit more oil rear rotor started making compression 30psi
front still didn't make any compression puled the engine out

when i was taking LIM of i noticed that the gasket was folded up and it was blocking primary intake port on the front iron ..don't know how that happened but could that mess with compression numbers in the front housing...
Old 06-11-12, 08:10 PM
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hey, u left the part out that you use sandpapers to "clean" your irons.

wonder why low compression? yeah, I wonder why too.
Old 06-12-12, 09:59 AM
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the way i cleaned up my irons is not the problem...or wrong

primary intake port on front iron was blocked and front is making compression

so got the compression front and rear engine is going back in
Old 06-14-12, 07:51 PM
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if u say so ~
Old 06-14-12, 09:27 PM
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push start it. and let it iidle for a while. dont turn it off. see how it goes
Old 06-24-12, 10:25 AM
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have you done the whole deflooding process on it as well, if you smell alot of gas coming out the exhaust it could be flooding, sometimes it will take a while for the engine to build compression, have you made sure that the car is getting proper oil pressure ? it takes a bit of cranking over before the oil will fully get through the entire system, i know this because it took a while to get my 2nd gen rx7 started.

as far as the whole low compression, if there is no compression building, there must be compression leaking out somewhere. you should be making minimum 90 psi (and that basically on an engine thats ready to die) , good compression on a rebuild would be like 120+ pretty much you want at least 100+ , depending on the wear of the rotors and housings and quality of rebuild youll have more.
Old 06-24-12, 03:28 PM
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here you go bro, your 30 psi reading could be because you did the compression test wrong, heres how to do the compression test, quoted from kevin landers / rotaryresurrection.com


NOTE - This guid designated For 2nd generation rx7s not rx8s, so everything may not be the same. But the theory is still the same.
Compression test using a piston engine tester :

1)

note battery strength. A weak battery will yield low compression results.

2)

Remove both lower plugs and wires.

3)

remove EGI fuse from engine fusebox.

4)

have a friend floor the accelerator pedal, opening the throttle for more airflow

5)

insert your tester into the leading hole

6)
hold the valve on the side of the tester open

7)
have your friend crank the car over for 5+ seconds.

8)
observe the needle bounces. You should see 3 in succession without skips, even bounces, in roughly the 30-35psi range.

9)
let out on the valve now, and let the tester reach an overall compression value for all 3 faces(highest of 3 will be displayed). 115+ is like new, 100-115 is healthy, 90-100 is getting weak(1 year or less in most cases) below 90 could blow at any moment.

10)
repeat for opposite rotor. Note difference in overall compression between rotors, which should be no more than 20psi max.
Old 07-05-12, 11:47 PM
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yea low compression numbers where do to battery and starter only turning engine at 150rpm instead of 250 rpm needed for the proper compression test or a Mazda compression tester that calculates all this stuff for you based on the rpm

problem was combination off stupid lil mistakes...rushing working late in to night...folded up gasket not letting any air in to front rotor...i had another gasket on hand so no big deal...switched some spark plug wires around- coil was connected to proper spark plug --- just the length or the wire was wrong

all sorted out,,, i have been driving it... about 500 miles on it now
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