1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

How do you tell a S4 block from an S5?

Thread Tools
 
Search this Thread
 
Old 11-24-03, 01:51 PM
  #1  
Senior Member

Thread Starter
 
Critoris's Avatar
 
Join Date: Mar 2003
Location: Da ATL
Posts: 264
Likes: 0
Received 0 Likes on 0 Posts
How do you tell a S4 block from an S5?

I found a guy that has 30 or so 13Bs around but doesn't know what year each one is. I'm looking for an S5 to rebuild with my 12A plates. How can you tell a S5 block from an S4? I'm not sure how much of the accessory stuff is on each, so the more basic the difference, the better.
Old 11-24-03, 03:07 PM
  #2  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,604 Likes on 1,847 Posts
the s4 has an egr valve right on top on the center iron. the s4 also has an aluminum water pump neck.
s5 has a 3 bolt metering pump, the s4 only has 2.
Old 11-24-03, 03:22 PM
  #3  
Got Boost?

 
fatboy7's Avatar
 
Join Date: Feb 2002
Location: Watertown, MA
Posts: 1,066
Likes: 0
Received 1 Like on 1 Post
like j9fd3s said,

EGR valve in intermediate plate = S4.
Aluminium water pump neck, with fill-up point = S4
Plastic water pump neck, with no fill-up point = S5

in addition,
Electric OMP = S5
Knock Sensor above spark plugs in the rotor housing = S5

Oh, BTW, you can't use 12A sideplates with 86+ 13B engines. They moved the water seals, so they're not compatable. If you want an 86+ 4port 13B, you need to get TII side housings, at least, and all the housings if you want to elminate the PITA exhaust port diffuser.
Old 11-24-03, 03:25 PM
  #4  
Senior Member

Thread Starter
 
Critoris's Avatar
 
Join Date: Mar 2003
Location: Da ATL
Posts: 264
Likes: 0
Received 0 Likes on 0 Posts
Okay, so in order to build a 4-port 13B for a 12A car, what's the easiest course of action? I have good 12A plates in the car now but want the S5 rotors. It looks like I need a turboII for the plates and housings and a S5 for the rotors. Dammit, there's two more motors to buy. Is there a more cost effective way to get where I'm going?
Old 11-24-03, 03:34 PM
  #5  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,604 Likes on 1,847 Posts
well you can get the s5 na rotating bits and for the rest either get

1. a t2 block
2. your 12a plates with gsl-se rotor housings

the t2 motor should be better, as it lets you keep the 12a together should you wanna sell it or put the car back to stock

mike
Old 11-24-03, 03:37 PM
  #6  
Senior Member

Thread Starter
 
Critoris's Avatar
 
Join Date: Mar 2003
Location: Da ATL
Posts: 264
Likes: 0
Received 0 Likes on 0 Posts
I still need the 12A front cover though, right?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Logan Reinisch
General Rotary Tech Support
44
09-17-18 12:20 PM
cook11
V-8 Powered RX-7's
1
10-02-15 11:52 AM
jarjarbinks
New Member RX-7 Technical
1
09-25-15 11:03 PM
MidnightOwl
2nd Generation Specific (1986-1992)
1
09-25-15 10:24 PM



Quick Reply: How do you tell a S4 block from an S5?



All times are GMT -5. The time now is 02:50 AM.