New Member RX-7 Technical Post your first technical questions here, in an easy flame free environment, before jumping into the main technical sections.

Compression build up

Old Jun 10, 2015 | 07:30 PM
  #1  
nasty's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2013
Posts: 14
Likes: 0
Compression build up

How long does it take for a rebuilt 13b to build compression. I heard its normal for a rebuild to have lower compression, but mine won't start with out being pulled. Once it's on it runs good but I'm wonder if I have a bad build I can almost never get it to start by turning the starter.
Reply
Old Jun 10, 2015 | 07:38 PM
  #2  
diabolical1's Avatar
Moderator
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Feb 2002
Posts: 10,998
Likes: 349
From: FL
what car?

have you confirmed where the timing is while it's running? another idea is to do a compression test after it's run and warm.
Reply
Old Jun 10, 2015 | 07:39 PM
  #3  
misterstyx69's Avatar
Retired Moderator, RIP
Tenured Member: 20 Years
iTrader: (142)
 
Joined: Sep 2005
Posts: 25,581
Likes: 136
From: Smiths Falls.(near Ottawa!.Mapquest IT!)
Did you test the engine to see what the actual compression is?
Normally it takes a couple 100km's to get everything properly settled.
Your compression numbers will come up as everything wears to where it should be,but it won't be a drastic change in Numbers..like if you start off with 50 and think that the numbers will end up as 110 then there is something askew.
BTW..50 is just a number for reference.If you rebuilt and tested at 50 then you would not have rebuilt the engine correctly and would need to address it
Reply
Old Jun 10, 2015 | 08:11 PM
  #4  
nasty's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2013
Posts: 14
Likes: 0
Timings good compression is 60 not much better than 50. I'm pretty upset. I was told this is all normal with these cars.
Reply
Old Jun 10, 2015 | 08:11 PM
  #5  
lastphaseofthis's Avatar
My job is to blow **** up
Tenured Member 20 Years
iTrader: (8)
 
Joined: Jan 2005
Posts: 2,903
Likes: 5
From: palmyra Indiana
Originally Posted by nasty
How long does it take for a rebuilt 13b to build compression. I heard its normal for a rebuild to have lower compression, but mine won't start with out being pulled. Once it's on it runs good but I'm wonder if I have a bad build I can almost never get it to start by turning the starter.
i've had a few go 20-50 miles before starting on their own, most start right away.
Reply
Old Jun 10, 2015 | 08:48 PM
  #6  
roTAR needz fundZ
Tenured Member 15 Years
iTrader: (1)
 
Joined: Aug 2002
Posts: 2,614
Likes: 31
From: Freeland, MI
Originally Posted by nasty
Timings good compression is 60 not much better than 50. I'm pretty upset. I was told this is all normal with these cars.
that is not that good, it may run, but I bet it doesn't have much power. even after a fresh rebuild you should have at least 100 psi

you could keep driving it and see what happens, but I wouldn't have very high hopes
Reply
Old Jun 11, 2015 | 01:01 PM
  #7  
diabolical1's Avatar
Moderator
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Feb 2002
Posts: 10,998
Likes: 349
From: FL
what new parts went into your rebuild?
Reply
Old Jun 12, 2015 | 09:50 PM
  #8  
nasty's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2013
Posts: 14
Likes: 0
New side seals and springs. Apex seals and springs. Corners seals. Thermal pellet and new seals.
Reply
Old Jun 12, 2015 | 10:29 PM
  #9  
roTAR needz fundZ
Tenured Member 15 Years
iTrader: (1)
 
Joined: Aug 2002
Posts: 2,614
Likes: 31
From: Freeland, MI
Compression build up

how were the housings is the next question?
Reply
Old Jun 12, 2015 | 11:59 PM
  #10  
nasty's Avatar
Thread Starter
Junior Member
 
Joined: Sep 2013
Posts: 14
Likes: 0
Originally Posted by lduley
how were the housings is the next question?
I replaced one housing and rotor the other looked like it was in good condition.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ZacMan
Build Threads
4
Sep 19, 2015 09:20 PM
BLK 93
3rd Generation Specific (1993-2002)
11
Sep 9, 2015 10:56 AM
ZaqAtaq
New Member RX-7 Technical
2
Sep 5, 2015 08:57 PM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 07:37 PM.