Front Engine Parts, Counterweights, Pulleys

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Engine Front End Pieces

 

Front Engine Assembly
See images above/below Description All-85 86-92 93-95
(1) Thrust Plate 11-5040-1011 11-5040-1011 11-D520-N390
(2) Thrust Bearing 11-505B-0813 11-505B-0813 11-D540-NF01
(2) Thrust Bearing (competition) 78-1840-0822 78-1840-0822 xxx
(3) End Spacers (see chart below)
(4) Bearing Plate 11-5010-1011 11-5010-1011 11-D510-N3H1
(5) Thrust Washer 11-5070-1011 11-5070-1011 11-D530-NF01
(6) Oil Pump Drive Gear 11-551A-0839 11-D750-N326 11-D750-N326
(7) Drive Gear 11-5310-0839 11-5310-0839 11-5310-0839
..... Key Way (front) 60-5710-9923 60-5710-9923 60-5710-9923
.... Key Way (rear/flywheel) 11-7050-0820 11-7050-0820 11-7050-0820
(8) Front Pulley Bolt Washer 22-8000-9956 22-8000-9956 Not Used
(9) Front Pulley Bolt (OEM) No Longer Available 11-420B-N318 11-4060-N3C1
Front Pulley Bolt (Titanium) 11-611B-0820-TI No Longer Available xxx
  Description All-85 86-92 93-95
(10) Front Bolt "O-ring" not used 10-1105-9954 10-1105-9954
(11) Front Eccentric Thermostat not used 11-D150-N326 11-D150-N326
Replacement for above thermostat, if you choose to not use it Thermostat Plug 11-PLUG (for 86-95)
(12) Eccentric Thermostat Spring not used 11-D170-N326 11-D170-N326
...... Oil Pump Gear No Longer Available 14-1430-N326 14-1430-N326
..... Oil Pump Chain 14-1420-0839 14-1510-N326 14-1510-N326
Oil Pump Lock Washer 91-2000-9997
Engine Front End Pieces

 

End Spacer Chart
Note- To achieve more end play, use a longer spacer, to achieve less end play, use a shorter spacer.
79-92 93-95
Thickness Part Number Thickness Part Number
(Z) 8.00mm 11-5090-0839 (A) 8mm(-.005/-.025) 11-D550-NF01
(V) 8.02mm 11-5020-0839 (B) 8mm(-.005/+.015) 11-D560-NF01
(Y) 8.04mm 11-5080-0839 (C) 8mm(+.015/+.035) 11-D570-NF01
(K) 8.06mm 11-5170-8519 (D) 8mm(+.035/+.055) 11-D580-NF01
(X) 8.08mm 11-5060-0839 (E) 8mm(+.055/+.075) 11-D590-NF01
(T) 8.10mm 11-5180-8534
(S) 8.12mm 23-1290-8871

 

Important note on counterweights: The front and rear (or flywheel) counterweights PLUS the rotors make a balanced assembly. The years / rotors we list in the following charts are for PRODUCTION years of the rotors / counterweights! A lot of mixing can be done when building engines, providing the rotors and counterweights match. By this we mean 89-92 non-turbo rotors (lighter weight, higher compression) can be used in an 84-85 13B engine as long as the matching front and rear counterweights are used also, for instance.

Balancing of the assembly is normally not needed, as long as the components are matched.

 

Front Counterweights
Engine/Rotors Year/Rotors Part Number Front Counterweight
12A 76-80 No Longer Available New-
call to ask for used part
81-82 No Longer Available New-
call to ask for used part
83-85 No Longer Available New-
call to ask for used part
13B 74-85 No Longer Available New-
call to ask for used part
86-88 No Longer Available New-
call to ask for used part
89-92 No Longer Available New-
call to ask for used part
93-95 A/T No Longer Available New-
call to ask for used part
93-95 M/T No Longer Available New-
call to ask for used part

 

Eccentric and Alternator Pulleys
These are "underdrive" pulleys - meaning the water pump and alternator will turn slower. This reduces horsepower loss from the drag of those units, and reduces the chance of water pump cavitation at higher rpm's.
Pulley Part Number Image
Single Belt Eccentric Pulley
3.25" OD
This pulley is provided with a series of engraved timing marks at 0 degrees (TDC), 12.5 degrees BTC, and 25 degrees BTC
11473 Single Belt Eccentric Pulley
Dual Belt Alternator Pulley 3" OD
Fits all Mazda RX Alternators -92
11479 Dual Belt Alternator Pulley
74-92 Underdrive Eccentric Pulley 4" OD
Timing marks at -10 (ATDC) 0, 10 (BTDC) and 20 (BTDC)
11469
Water Pump Pulley 5" OD
Slows down water pump for racing applications
Fits 79-85 water pumps
Will NOT fit with stock eccentric shaft pulley
Must use 11473
01-7211-0000 Water Pump Pulley
Water Pump Pulley 5" OD
Slows down water pump for racing applications
Fits 86-88 water pumps
Will NOT fit with stock eccentric shaft pulley
Must use 11473
01-7212-0000 Water Pump Pulley
Water Pump Pulley 5" OD
Slows down water pump for racing applications
Fits 89-92 water pumps
Will NOT fit with stock eccentric shaft pulley
Must use 11473
01-7213-0000 Water Pump Pulley
Note: If you have removed the air pump, the remaining belt does not wrap very far around the water pump pulley. This lack of belt contact area area can lead to slippage of the water pump at high rpm's/high load conditions. The "high load" can be caused by the fan itself, or by the fan clutch being too stiff and/or frozen.

We strongly recommend using at least the dual belt alternator pulley to double the water pump pulley belt contact area.

Please read FAQ at:Front Pulley / Thrust Bearings to help prevent problems when changing front pully.

 

Stock OEM have the "counterweight" built into the flywheels. The rear counterweights listed here are needed when using aftermarket light flywheels that bolt to the counterweight.
See our FAQ Identifying Flywheels if you are not sure what year of flywheel you have.

 

Rear Counterweights
Engine/Rotors Year/Rotors Part Number Rear Counterweight
12A 79-82 11-751A-1883
83-85 No Longer Available
13B 76-85 11-751A-1029
86-88 11-52X0-N3Y8
89-95 11-52X0-N3Y6
You may want to read our FAQ on Identifying Rear Counterweights
All Rotary - Flywheel Nut 11-711C-0810 Flywheel Nut
All Rotary - Flywheel Nut Titanium 11-711C-0810-TI

 

Front Cover Gaskets and "O" Ring / Sealing Washer
It is mandatory that you read our: '86-92 "O-Ring Problem" FAQ Page
74-85 and Some 86-88
Front Cover Gasket
(For O-ring only type)
For 86-92, Do not order without reading FAQ above!!
10-5020-N2Y0
~86-92
Front Cover Gasket
(For O-ring AND Teflon Seal type)
Do not order without reading FAQ above!!
10-5020-N386
93-95 Front Cover Gasket 10-5020-N3A1
Metal Front Cover Gasket (13B-RE)
This metal gasket works on all front covers and seals better than the stock paper gasket.
-This is a direct replacement for the 93-95 gasket.
-The upper most bolt hole on the right side will not be utilized on 79-92 front covers.
10-5020-N390
04-08 RX8 Front Cover Gasket
Many people like to use this gasket on the 86-92 engines due to the improved
sealing at the front cover and water pump housing.
-The upper right bolt hole does not line up with the 93-95 engine.
-The water pump gasket is not correct for the 79-85 engines.
10-502B-N3H1
Front Cover O-ring (All) 10-1740-N231
White Nylon/Teflon sealing washer that goes around the O-ring
(Be sure you have read the FAQ)
10-C150-N326
Front Main Seal All -92 10-6050-0820
Front Main Seal 93-95 10-5070-N3R1

 

Engine Front Covers
Year & Engine Part Number
Generic Pictures
79-85 12A No Longer Available
84-85 13B GSLSE No Longer Available
86-88 NON-TURBO No Longer Available
86-88 TURBO No Longer Available
93-95 No Longer Available
04-08 RX-8 10-500J-N3H1
09-11 RX8 10-500B-N3R1

 

Dowel Pins - 4 used in each engine 12A 10-111B-0839
13B 10-1110-1757

 

Tension Bolts
Generic Tension Bolt 12A Long No Longer Available
Short No Longer Available
13B Long 10-452A-1757
Short 10-451B-1757
Long Ribbed 10-E61A-N350
Short Ribbed 10-E51B-N350
Tension Bolt Seal Seal for any of the above tension bolts (each) 74-95 10-4550-0839

 

Main Engine Parts Page

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