weird comp #'s
08-09-04, 07:15 AM
#1
BOOSTED Vert
Thread Starter
Join Date: Sep 2002
Location: Miami
Posts: 2,307
Likes: 0
Received 0 Likes
on
0 Posts
weird comp #'s
Ok I just had rebuilt my engine and it has about 1 hour total of idle time. I never had done a comp test before but since this **** was not idling only after 2krpms, I decided to do it and came with these strange as numbers.... The front rotor was 120 psi, and rear was about 60psi or a lil less... the seals that I used were RA seals, and when I looked at the housings they looked great..... I am gonna rebuild it again using the same seals but I want to port it, and also replace everything else I didnt replace the first time. But I dont want to go through the trouble of rebuilding it again and this **** having the same #'s... O **** I just thought of something... The motor has compression entering the coolant, so could it be why its giving me some outrageously low #'s ?
08-09-04, 07:34 AM
#2
Seduced by the DARK SIDE
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes
on
2 Posts
1) You're still early in the break in.
2) On a rorary engine, you look at all three faces on the same test, so you have to open the schrader valve while cranking to read the seperate pulses from each face.
3) Test in the trailing hole with the leading plugs in.
Check out www.rotaryresurrection.com - in the tech section - good info on break in.
2) On a rorary engine, you look at all three faces on the same test, so you have to open the schrader valve while cranking to read the seperate pulses from each face.
3) Test in the trailing hole with the leading plugs in.
Check out www.rotaryresurrection.com - in the tech section - good info on break in.
Last edited by SureShot; 08-09-04 at 07:42 AM.
08-09-04, 08:10 AM
#3
Lives on the Forum
Originally Posted by MARTIN
O **** I just thought of something... The motor has compression entering the coolant, so could it be why its giving me some outrageously low #'s ?
-Ted
08-09-04, 08:23 AM
#4
Seduced by the DARK SIDE
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by RETed
Uh, NO motor should have a coolant seal compromise unless it's a BAD motor....
Looks like maybe an O ring got pinched during assembly.
08-09-04, 08:52 AM
#5
Locust of the apocalypse
Join Date: Apr 2003
Location: Directly above the center of the earth (York, PA)
Posts: 2,553
Likes: 0
Received 1 Like
on
1 Post
If you have compression entering the coolant system, id say thats 99% probability that it is also why you have low compression #'s on the rear rotor and that there is a coolant seal pinched or a channel groove broken in the rear section... BUT, the front rotor is good, there is a good chance you may get away with just lifting the back of the motor off and replacing the rear water o-rings, you may have pinched one during assembly...
HOWEVER.. it could be more serious, if you didn't clean the o-ring grooves out completely, and left a hunk of carbon in there, you could have broken a piece of the retaining wall for the o-ring out into the water jacket, that can't be fixed and are looking at replacing an iron. This is especially true if you use the R/A teflon encapsulated o-rings. My buddy did a half assed job at cleaning up his parts and did just that, except his fronnt iron broke.
I hope you just got a seal pinched. Regarless, when you take it apart, make sure that the o-ring channels are 100% free of carbon before you put it back together.
As for porting, i just did it, its easy.. Get the template from Mazdatrix, get a GOOD QUALITY carbide burr ( i use a 1/2 inch cutting diameter round nose, double cut carbide burr from grainger), some sanding cones (screw the stones, if you do a good job with the burr, you can skip right to the sandpaper cones and not dick with the stOnes) and a air powered die grinder
HOWEVER.. it could be more serious, if you didn't clean the o-ring grooves out completely, and left a hunk of carbon in there, you could have broken a piece of the retaining wall for the o-ring out into the water jacket, that can't be fixed and are looking at replacing an iron. This is especially true if you use the R/A teflon encapsulated o-rings. My buddy did a half assed job at cleaning up his parts and did just that, except his fronnt iron broke.
I hope you just got a seal pinched. Regarless, when you take it apart, make sure that the o-ring channels are 100% free of carbon before you put it back together.
As for porting, i just did it, its easy.. Get the template from Mazdatrix, get a GOOD QUALITY carbide burr ( i use a 1/2 inch cutting diameter round nose, double cut carbide burr from grainger), some sanding cones (screw the stones, if you do a good job with the burr, you can skip right to the sandpaper cones and not dick with the stOnes) and a air powered die grinder
08-09-04, 08:24 PM
#6
BOOSTED Vert
Thread Starter
Join Date: Sep 2002
Location: Miami
Posts: 2,307
Likes: 0
Received 0 Likes
on
0 Posts
I thought that I had pinched a seal at first... but Its too much compression entering the coolant lines.... when I cranked the motor to do the compression test I opened the rad. cap and mad air came out. I think one of the irons is fucked...and I did one of those solo comp. test. so I could crank the car and look at the guage at the same time.... its a fresh build which is why Im not really worried about each face cus I know all the seals are good.... anyways... thanks for everything... O and about the porting imma send it somewhere to be done, dont really want to **** around with it...
Thread
Thread Starter
Forum
Replies
Last Post
Turblown
Vendor Classifieds
12
10-17-20 03:25 PM
LongDuck
1st Generation Specific (1979-1985)
12
10-07-15 08:12 PM