Interesting find after tearing down a Factory Reman...
06-06-11, 07:44 PM
#1
Interesting find after tearing down a Factory Reman...
So, last weekend I tore down a engine core I bought. It was out of a S5 NA convertible with an Auto. The miles were pretty low (<100k) and it was an auto (presumably less abused than a 5 speed)
I was pretty happy with how everything looked. Very little iron wear and only a small spot of chrome flake. The housings still had the reman stamped seals and there was a clean Mazda barcode and sticker on the oil pan.
Here's where it gets interesting...
After cleaning up the rotors, I noticed that the front had machined combustion chambers and the rear had cast ones. After doing a little research, it seems that one is S4 and one is S5. Since this was assumed to be an S5 motor (had the appropriate intake and waterpump), I am now questioning which counterweights it has. I have attached pictures of each on a scale.
Note: It is POUNDS:OUNCES:0.1 OUNCES
AND: This scale maxes out at 11#, so the numbers aren't 100% accurate.
I was pretty happy with how everything looked. Very little iron wear and only a small spot of chrome flake. The housings still had the reman stamped seals and there was a clean Mazda barcode and sticker on the oil pan.
Here's where it gets interesting...
After cleaning up the rotors, I noticed that the front had machined combustion chambers and the rear had cast ones. After doing a little research, it seems that one is S4 and one is S5. Since this was assumed to be an S5 motor (had the appropriate intake and waterpump), I am now questioning which counterweights it has. I have attached pictures of each on a scale.
Note: It is POUNDS:OUNCES:0.1 OUNCES
AND: This scale maxes out at 11#, so the numbers aren't 100% accurate.
Last edited by Shainiac; 06-06-11 at 08:06 PM. Reason: Photos didnt work
06-06-11, 08:43 PM
#2
Old [Sch|F]ool
I've heard that about the later Mazda remans... the remanufacturing was subbed out to a company that would just throw all the rotors into one pile, flywheels into another pile, counterweights into another, and just grab whatever and put it in an engine.
Well, that one lasted through its warranty period, anyway. That's all that matters, as long as the return rate doesn't outmatch the profit margin, there's no incentive to change things either.
I don't know how many "remanufactured" parts are just cleaned up, repainted, and shipped back out again. Given how many people diagnose by throwing parts at a car, and thereby returning a perfectly good unit as a core, it probably works well enough as a business model.
I have one of these later remans sitting in the Garage of Doom. It's allegedly a '79 engine. It lasted about 40k before it quit.
Well, that one lasted through its warranty period, anyway. That's all that matters, as long as the return rate doesn't outmatch the profit margin, there's no incentive to change things either.
I don't know how many "remanufactured" parts are just cleaned up, repainted, and shipped back out again. Given how many people diagnose by throwing parts at a car, and thereby returning a perfectly good unit as a core, it probably works well enough as a business model.
I have one of these later remans sitting in the Garage of Doom. It's allegedly a '79 engine. It lasted about 40k before it quit.
06-06-11, 09:00 PM
#5
talking head
https://www.rx7club.com/showthread.p...=counterweight
measure the width of the flats on the rear mass,, and the thickness of the bob mass of the front weight
methinks you may have 1 s4 turbo rotor ( 8.5:1 ) and 1 NA s5 rotor ( 9.7:1 )
measure the width of the flats on the rear mass,, and the thickness of the bob mass of the front weight
methinks you may have 1 s4 turbo rotor ( 8.5:1 ) and 1 NA s5 rotor ( 9.7:1 )
06-06-11, 09:53 PM
#7
talking head
you can measure the bath CC to be absolutely sure
but i find the quick ID is to look at the bath and there is usually a strike at one end that resembles an "I" but i think may once have been a "T" ( only for s4 T rotors )
NA s4 rotors have nothing
i have many rotor sets here ,,and that is common on all the s4 turbo rotors, i will take a pic later for you
but i find the quick ID is to look at the bath and there is usually a strike at one end that resembles an "I" but i think may once have been a "T" ( only for s4 T rotors )
NA s4 rotors have nothing
i have many rotor sets here ,,and that is common on all the s4 turbo rotors, i will take a pic later for you
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06-06-11, 10:10 PM
#9
Old [Sch|F]ool
I thought the only rotors with milled bathtubs were FD. The S5 T2 engine I yanked apart had cast tubs.
...then again, it also had been milled for 3mm seals, so who knows what rotors it had?
...then again, it also had been milled for 3mm seals, so who knows what rotors it had?
06-06-11, 10:20 PM
#10
Here's pictures of the main bearings. It's kind of hard see, but when the stat gears are bolted in accordance to the pins in the irons, the bearing wear is in the bottom left (front gear, from looking at the front) and bottom right (rear gear, from looking at the front)
06-07-11, 01:31 AM
#12
talking head
the " I " strike
pictures arent the best on my old phone but you should be able to see slightly different baths on the s5 and s5 NA and the I strike on the two s4T rotor baths
( in identical positions )
FD rotors would be ID'd by the three window bearing but is mostly like the s5
06-08-11, 12:36 PM
#14
A bit of an update on how fucked up this motor was:
The front counterweight is an S4, the rear CW is questionable. The posted weight for the S4 and S5 rear CW is both 4.0#. Although they definitely have a different CG, I have no weigh to measure that. It weighs within 20g of the rear CW I bough that was supposedly an S5, but now I'm even questioning that lol. Both rear CWs have 3 drilled balancing holes, but at different spacing.
Anyone know what an acceptable differences in rotor weights is?
Here are the listings for the 3 S5 NA rotors I have stockpiled.
4310 E
4365 C
4412 C
Also, would it be acceptable to use an end mill on a drill press to increase the depth of the existing balancing holes on the rotor?
The front counterweight is an S4, the rear CW is questionable. The posted weight for the S4 and S5 rear CW is both 4.0#. Although they definitely have a different CG, I have no weigh to measure that. It weighs within 20g of the rear CW I bough that was supposedly an S5, but now I'm even questioning that lol. Both rear CWs have 3 drilled balancing holes, but at different spacing.
Anyone know what an acceptable differences in rotor weights is?
Here are the listings for the 3 S5 NA rotors I have stockpiled.
4310 E
4365 C
4412 C
Also, would it be acceptable to use an end mill on a drill press to increase the depth of the existing balancing holes on the rotor?
06-08-11, 07:31 PM
#15
talking head
stop messing about with scales with a fidelity too low to spot the differences
s5 rear i believe is actually 1840 grams ish
measure the rim flats without the chamfer edge, mazdatrix also list under the same method ( but in imperial measurement )
the best identifier -
the inside edge rim flats ( without chamfer ) will measure between
11.68 to 12.14 mm wide
measured thus -
my rear weight ID data ---
89-95 13B
-N351-11-5210---------12.52 to 12.85 mm
86-88 13B
-N327-11-521A--------13.23 to 13.92 mm
76-85 13B
-1029-11-751A--------11.68 to 12.14 mm
( NB older versions may be stamped 1029A, 1029 or 29 )
83-85 12A
-N226-11-751A---------6.07 to 7.01 mm
79-82 12A
-1883-11-751A-------- 8.25 to 9.17mm
------------------------------
my front weight ID data ---
1881-11-511 ,,4 port 12a 74-80
1.3kg, 26.5 mm thick 180 degree mass , no chamfer, marked cast "B" on either one of the mass edge flats
for use with 12a flywheel with wide outer mass ring
or for use with 1883-11-751A rear auto counterweight
-----------------
N201 -11-511,, 81-82 12a rx7
1 kg, 29.7 mm thick mass with approx 100 degree angle, parallel edges on the mass with no chamfer edge
intended for use with rx7 8.5 clutch / flywheel with small outer ring mass
( marked cast 21 on flywheel rear )
-- is this including 12a six port and 12a turbo and aus s3 12a with 9.0 ( 225 mm ) flywheel and clutch )?
anybody with definite pics and dimensions for N226-11-511?
---------------------------
74-85 13b stamped 1757 ( a 1974 rx4 13b code )
1.3 kg ,28 mm thick 180 degree mass, no chamfer edge , cast "I" or dash stamped into one of the flat ends of the mass
sometimes marked 1757 also with an unrelated factory number
( this one marked F356 )
NB
- some sources say only suit 74-83 and quote N304-11-511 for 83-85 13b
( although 13b rotor masses are unchanged 74-85 )
other sources quote N304-11-511 as replacement for 74-85
( as 1757-11-511 is NLA from mazda )
as such consider that N304 and 1757 weights are interchangeable
------------------
N326-11-511, s4 13b ( and 13bt ) ,, 1.3 kg , 26.0 mm thick , 180 degree mass, small chamfer edge 8mm wide,, fine machine grooved finish
------------------
N350-11-511,s5 13b ( and 13bt ) ,,1.2kg,23.4mm thick, 180 degree mass, small chamfer edge 5mm wide, fine machine groove finish,, small torrington surface
( as distinct from FD large torrington thrust face surface )
s5 rear i believe is actually 1840 grams ish
measure the rim flats without the chamfer edge, mazdatrix also list under the same method ( but in imperial measurement )
the best identifier -
the inside edge rim flats ( without chamfer ) will measure between
11.68 to 12.14 mm wide
measured thus -
my rear weight ID data ---
89-95 13B
-N351-11-5210---------12.52 to 12.85 mm
86-88 13B
-N327-11-521A--------13.23 to 13.92 mm
76-85 13B
-1029-11-751A--------11.68 to 12.14 mm
( NB older versions may be stamped 1029A, 1029 or 29 )
83-85 12A
-N226-11-751A---------6.07 to 7.01 mm
79-82 12A
-1883-11-751A-------- 8.25 to 9.17mm
------------------------------
my front weight ID data ---
1881-11-511 ,,4 port 12a 74-80
1.3kg, 26.5 mm thick 180 degree mass , no chamfer, marked cast "B" on either one of the mass edge flats
for use with 12a flywheel with wide outer mass ring
or for use with 1883-11-751A rear auto counterweight
-----------------
N201 -11-511,, 81-82 12a rx7
1 kg, 29.7 mm thick mass with approx 100 degree angle, parallel edges on the mass with no chamfer edge
intended for use with rx7 8.5 clutch / flywheel with small outer ring mass
( marked cast 21 on flywheel rear )
-- is this including 12a six port and 12a turbo and aus s3 12a with 9.0 ( 225 mm ) flywheel and clutch )?
anybody with definite pics and dimensions for N226-11-511?
---------------------------
74-85 13b stamped 1757 ( a 1974 rx4 13b code )
1.3 kg ,28 mm thick 180 degree mass, no chamfer edge , cast "I" or dash stamped into one of the flat ends of the mass
sometimes marked 1757 also with an unrelated factory number
( this one marked F356 )
NB
- some sources say only suit 74-83 and quote N304-11-511 for 83-85 13b
( although 13b rotor masses are unchanged 74-85 )
other sources quote N304-11-511 as replacement for 74-85
( as 1757-11-511 is NLA from mazda )
as such consider that N304 and 1757 weights are interchangeable
------------------
N326-11-511, s4 13b ( and 13bt ) ,, 1.3 kg , 26.0 mm thick , 180 degree mass, small chamfer edge 8mm wide,, fine machine grooved finish
------------------
N350-11-511,s5 13b ( and 13bt ) ,,1.2kg,23.4mm thick, 180 degree mass, small chamfer edge 5mm wide, fine machine groove finish,, small torrington surface
( as distinct from FD large torrington thrust face surface )
06-08-11, 10:06 PM
#16
^Thanks for that 
Rear CW was S5, front CW S4.
Another weird thing I noticed, the apex springs are WEEEEIRD. They are about .175" OVER spec. I've attached a picture of the springs. The lower springs are from various S4/S5 2mm engines with normal wear and spec out within the acceptable range. The upper springs are the ones from this motor. What the hell? Also, anyone want any OEM 3-piece seals? These only have around .010" of wear :/
Rear CW was S5, front CW S4.
Another weird thing I noticed, the apex springs are WEEEEIRD. They are about .175" OVER spec. I've attached a picture of the springs. The lower springs are from various S4/S5 2mm engines with normal wear and spec out within the acceptable range. The upper springs are the ones from this motor. What the hell? Also, anyone want any OEM 3-piece seals? These only have around .010" of wear :/
06-09-11, 02:27 AM
#17
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A bit of an update on how fucked up this motor was:
The front counterweight is an S4, the rear CW is questionable. The posted weight for the S4 and S5 rear CW is both 4.0#. Although they definitely have a different CG, I have no weigh to measure that. It weighs within 20g of the rear CW I bough that was supposedly an S5, but now I'm even questioning that lol. Both rear CWs have 3 drilled balancing holes, but at different spacing.
Anyone know what an acceptable differences in rotor weights is?
Here are the listings for the 3 S5 NA rotors I have stockpiled.
4310 E
4365 C
4412 C
Also, would it be acceptable to use an end mill on a drill press to increase the depth of the existing balancing holes on the rotor?
The front counterweight is an S4, the rear CW is questionable. The posted weight for the S4 and S5 rear CW is both 4.0#. Although they definitely have a different CG, I have no weigh to measure that. It weighs within 20g of the rear CW I bough that was supposedly an S5, but now I'm even questioning that lol. Both rear CWs have 3 drilled balancing holes, but at different spacing.
Anyone know what an acceptable differences in rotor weights is?
Here are the listings for the 3 S5 NA rotors I have stockpiled.
4310 E
4365 C
4412 C
Also, would it be acceptable to use an end mill on a drill press to increase the depth of the existing balancing holes on the rotor?
I have seen a wider spread than 55g come out of a factory balanced engine without copper showing.
You can mill at the balance holes - you probably want an accurate mill and scale.
Note that the big balance holes are conical, complifying the milling if you don't have a matched conical bit.
You may want to check there is enough meat if you need to machine in an already deep balance hole.
06-09-11, 02:27 AM
#18
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Another Franken-motor...that probably ran fine.
A bunch of CWs I have measured with a 1g accuracy scale:
S4 ~1855g (1850-1863)
S5/6 ~1830g (1827-1833)
S6 new aftermarket - 1809g
cosmo - 1813g
unknown - 1845g
Depth of combustion recess measured across the face:
S4 NA ~0.390" (rough cast recess)
S5 NA ~0.350" (machined)
S5/6T ~0.430" (machined)
S4T ~none measured (rough cast)
A bunch of CWs I have measured with a 1g accuracy scale:
S4 ~1855g (1850-1863)
S5/6 ~1830g (1827-1833)
S6 new aftermarket - 1809g
cosmo - 1813g
unknown - 1845g
Depth of combustion recess measured across the face:
S4 NA ~0.390" (rough cast recess)
S5 NA ~0.350" (machined)
S5/6T ~0.430" (machined)
S4T ~none measured (rough cast)
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