rotarenvy

I have a spare motor sitting on my bench and I was using it to design a new pulley for my supercharger.

after settling on a design, I tried to fit the pulley to original motor in my car and found it was way to big to fit.

checking out the differences between the motors I found the timing plate is much larger and the front Plate is a different casting. not by much, they look identical but a few locations change by 10mm or so.

I'm wondering if this was a pre-production motor or a motor from another market.

has anyone encountered any front plate variations in series 1 motors?

ASH8

Yes there are 5 "iterations" of the front alloy Timing or Oil Pump Cover from production in Series 1's

N3H1-10-500E Start of production used up to 25th July, 2003
N3H1-10-500F * From 25th July 2003 to 1st October 2003
N3H1-10-500G * From 1st October 2003 to 1st April 2006
N3H1-10-500H # From 1st April 2006 on-wards till end Series 1's.
N3H1-10-500J Part and Part Number update and Super-session

* Means interchangeability is One Way, New Part will fit in place old, but Old Part
Can NOT be used where the superseded Cover was originally used.
# Means both Parts are interchangeable with each other, a H for a G or a G for a H.

rotarenvy

thanks Ash, your full of usefull info!

I guess I have an E and a G then since I couldn't swap the plates either way.

ASH8

Yes, sort of..

You could of had an E Cover and trying to fit on an engine that had an F or a G originally fitted,
or an F and trying to fit on a G installation.
Or an E trying to fit on a G as you said.

The only way to truly check is IF you have the Chassis Number or VIN Number of the RX-8 the Spare Engine or engine cover came from, Mazda ONLY cross references VIN (Chassis) Numbers which also tells Production Date. Sometimes they will brand the part itself with a letter or part number reference on either side of Cover.

So if you ever get used parts from a Wreck, always get the cars VIN Number (s), it can save lots of Head F's.