2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

ramblings...out of the car compression test results

Thread Tools
 
Search this Thread
 
Old 03-13-04, 11:29 PM
  #1  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
ramblings...out of the car compression test results

I dunno why I'm even posting this. I guess it cuz im bored. I pulled the motor out of the crate I shipped it on, had it on the crane. I hooked up a spare tranny bellhousing, with a starter. I built this motor a couple of years ago in Japan. I streetported it also. I never compression tested it, I guess cuz I was afraid that itg was low, although it idled perfectly and pulled hard. Heres my results aft about 6 months without being started. I poured some oil in the exhaust ports and let her rip...this is pretty ghetto, until I get my shop set up..anyway, heres the pics...
Old 03-13-04, 11:32 PM
  #2  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
heres another...
Old 03-13-04, 11:37 PM
  #3  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
heres the front rotor compression numbers....speed was a bit slow at 218 rpm
Old 03-13-04, 11:39 PM
  #4  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
and the rear compression results....not bad, eh?
Old 03-14-04, 12:08 AM
  #5  
Clogged cat

iTrader: (3)
 
koukifc3s's Avatar
 
Join Date: Sep 2002
Location: Orange County, CA
Posts: 2,000
Likes: 0
Received 0 Likes on 0 Posts
wow congrats!
Old 03-14-04, 12:13 AM
  #6  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
thanks kouki
Old 03-14-04, 12:17 AM
  #7  
So close to 12's!!!

 
Join Date: Aug 2003
Location: Canada
Posts: 395
Likes: 0
Received 0 Likes on 0 Posts
whats the conversion into psi on those mazda testers?
Old 03-14-04, 12:24 AM
  #8  
Rotary Enthusiast

 
fstrnyou's Avatar
 
Join Date: Sep 2002
Location: Statesboro, GA
Posts: 1,233
Likes: 0
Received 0 Likes on 0 Posts
kg/cm^2 x 14.223 = psi

9.3 kg/cm^2 = 132psi
9.8 kg/cm^2 = 139psi

and those numbers are soo inaccurate because he added oil to the chambers. the oil sealed up all the possible compression leaks that would have normally existed.

granted, i would have added some sort of lubricant as well. be kinda dumb to crank a motor that has been sitting for such a long time without lubing the housings. just not a convenient time to do a compression check. also, motor is supposed to be warm and at WOT.

i'm not flaming you or anything, just giving my imput....

Last edited by fstrnyou; 03-14-04 at 12:26 AM.
Old 03-14-04, 12:26 AM
  #9  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
uh....um...hmm...let me think a minute....ok, 9.5 bar is 137.7 psi

so, going by that calculation, my compression is as follows in PSI for all you non metric users

front 134.8, 134.8 , 133.4 (psi)
rear 142.1, 143.5, 140.6 (psi)
Old 03-14-04, 12:31 AM
  #10  
Merovingeon


Thread Starter
iTrader: (5)
 
onefastrx7turbo's Avatar
 
Join Date: Aug 2002
Location: formerly japan, now Goodyear, az
Posts: 903
Received 6 Likes on 3 Posts
fstrnyou,

I know the motor is supposed to be warmed up, and all that. But I added oil just as you said, just to have lube. I didnt want to be cranking a motor that has been out of a car for 6 months. Also, as metal heats up, shouldnt the numbers be better, not worse? I dunno. I just wanted to see what i would get. Also, there were no manifolds installed, so, theoretically, it was at WOT...im not trying to flame you, im just trying to clear things up. im not trying to say this is my compression in normal use. this is what my compression looks like after not running for 8 months and a capful of oil into each chamber, and cranking slow...
Old 03-14-04, 12:33 AM
  #11  
Rotary Enthusiast

 
fstrnyou's Avatar
 
Join Date: Sep 2002
Location: Statesboro, GA
Posts: 1,233
Likes: 0
Received 0 Likes on 0 Posts
yeah, no problems at all, and besides, i'm not the one to talk about compression numbers. i just tested mine the other day and i'm only getting 85psi in the rear rotar and 65psi in the front. needless to say, i'm not driving it anymore until i rebuild it.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
LunchboxSA22
2nd Generation Specific (1986-1992)
37
10-26-15 10:53 AM
fastrx7man
3rd Generation Specific (1993-2002)
33
09-02-15 09:42 PM



Quick Reply: ramblings...out of the car compression test results



All times are GMT -5. The time now is 04:13 PM.