Could this be the reason for my low compression?
07-15-12, 03:20 PM
#1
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Could this be the reason for my low compression?
[IMG]<a href="http://s915.photobucket.com/albums/ac351/broumad/?action=view&current=2ndhousing-1.jpg" target="_blank"><img src="http://i915.photobucket.com/albums/ac351/broumad/2ndhousing-1.jpg" border="0" alt="Photobucket"></a>[/IMG]
Apparently, near my exhaust port, the housings' chrome surface chipped (the red circled area).
These are fairly new housings and there are no other scratches or gouges within the housings. I am essentially asking whether this would affect my compression significantly enough to where i would need to get a new housing. Or because it is near the exhaust it doesn't matter.
Anyways, feedback would be great.
Thank you!
Apparently, near my exhaust port, the housings' chrome surface chipped (the red circled area).
These are fairly new housings and there are no other scratches or gouges within the housings. I am essentially asking whether this would affect my compression significantly enough to where i would need to get a new housing. Or because it is near the exhaust it doesn't matter.
Anyways, feedback would be great.
Thank you!
07-15-12, 04:07 PM
#2
Where its after the port it would affectit if it is, because only before or right on it will be where the compression is exiting the engine, after the apex seal passes over the exhaust port its the start a completely different cycle in the engine.
What kind if compression numbers are we talking? 95-100? If its anything less than that you're majorly leaking compression.
My theory - Lower compression (in my opinion) will be in an engine with internals that are worn to a degree (not apex seals; but the housings/rotors etc).
The wear will result in a lower compression number, although the engine should still last just as long, just will have lower compression than an engine that has internals very close to spec of brand new.
The engine rebuilds with great quality internals will yield substantially higher compression, basically you get what you put into it, its all in what you can afford and what your expectations are, find a happy medium.
What kind if compression numbers are we talking? 95-100? If its anything less than that you're majorly leaking compression.
My theory - Lower compression (in my opinion) will be in an engine with internals that are worn to a degree (not apex seals; but the housings/rotors etc).
The wear will result in a lower compression number, although the engine should still last just as long, just will have lower compression than an engine that has internals very close to spec of brand new.
The engine rebuilds with great quality internals will yield substantially higher compression, basically you get what you put into it, its all in what you can afford and what your expectations are, find a happy medium.
07-15-12, 04:20 PM
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Where its after the port it would affectit if it is, because only before or right on it will be where the compression is exiting the engine, after the apex seal passes over the exhaust port its the start a completely different cycle in the engine.
What kind if compression numbers are we talking? 95-100? If its anything less than that you're majorly leaking compression.
My theory - Lower compression (in my opinion) will be in an engine with internals that are worn to a degree (not apex seals; but the housings/rotors etc).
The wear will result in a lower compression number, although the engine should still last just as long, just will have lower compression than an engine that has internals very close to spec of brand new.
The engine rebuilds with great quality internals will yield substantially higher compression, basically you get what you put into it, its all in what you can afford and what your expectations are, find a happy medium.
What kind if compression numbers are we talking? 95-100? If its anything less than that you're majorly leaking compression.
My theory - Lower compression (in my opinion) will be in an engine with internals that are worn to a degree (not apex seals; but the housings/rotors etc).
The wear will result in a lower compression number, although the engine should still last just as long, just will have lower compression than an engine that has internals very close to spec of brand new.
The engine rebuilds with great quality internals will yield substantially higher compression, basically you get what you put into it, its all in what you can afford and what your expectations are, find a happy medium.
Thing is, it has brand new everything (except the rotors which are off an 87 n/a). Endplates are new, apex seals, side seals (with proper clearing), corner seals, all the springs are new. My compression was at around like 6 after i rebuilt it and i thought that i may have torqued the endplate in the back down incorrectly, but now that i have seen this housing i really don't know what to think.
I could put it together again today or tomorrow and compression test it if i wanted to because i have all of the parts, but i wanna wait and find out whether this is really the problem or not.
07-15-12, 04:29 PM
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What do you guys think? Keep this housing and try it since its just under 2mm of chipping, or get a new housing?
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07-15-12, 05:16 PM
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I guess i meant to say 60. Apparently anywhere above 70 is good and 90 is ideal is what the mazda techs told me. When i brought up 110 being ideal about a month back they were like "lol no thats impossible don't listen to people on the forums."
07-15-12, 05:26 PM
#12
Well I never actually measured my compression on my old rx7 but @bove 70 and below 90 is still low in my opinion and unless you should have way more than 60, id be surprised if it Idles with it that low of compression.
Get it idling/running and driving, break it in, and see what the compression is after.
Oh and fyi, I wouldn't trust a Mazda tech its not like they all specialize in rebuilding rotary engines, talk to someone that has built one.
Get it idling/running and driving, break it in, and see what the compression is after.
Oh and fyi, I wouldn't trust a Mazda tech its not like they all specialize in rebuilding rotary engines, talk to someone that has built one.
07-15-12, 06:59 PM
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Contact one of the vendors who can refurbish housings, Goopy does it but there's another shop that does it on the West Coast that I cant remember atm. There's a thread about it.
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