Miata Mailing List: October 1994, Message #115
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   From: Doug Hagerman 
Subject: Re: DAILY digest of "miata" mailing list (part 1 of 1)
   Date: Fri, 7 Oct 1994 10:25:36 -0400


>    Does the Miata use an engine block from the Mazda 323?  
>    
>    Is the transmission really derived from an RX-7?
>    
>    Final question:  Is the '94 Miata's engine fundamentally different 
> than a '90-'93 Miata's or just small differences?  
> 

I haven't personally examined the blocks, but statements published in
a number of places claim that the 1600 cc Miata uses a block based on
the 323 block. If you've ever been around a mechanical engineering
development project you'll understand why there's such an inclination
to reuse a block design--it's incredibly hard to get the right combination
of strength, weight, good cooling, cheap, reliable, and immunity to
mechanical resonances. Once you get a good design in place there's no
particular reason to try to invent another one.

The 323 block is used in a large number of cars,
as is the 323 mechanical platform. I suspect that Mazda gets a fair
amount of their income from supplying this stuff to other companies.

The transmission has also been stated by Mazda to be based on an
earlier RX-7 design, probably for the same reason as above. Actually
the claim is that the transmission design originated in a light
truck application.

I believe that the '94 block is a "different" block, not a bored or
stroked 323 block. I'm sure there is a fair amount of commonality
in the design simply because Mazda is a pretty small company.

Historical examples along this line include the Coventry Climax engine
used in a number of 1950 era British cars, which originated as a
portable engine for use with fire pumps. The 323 platform is used on
the Lotus Elan (new version) as well as the Mercury Capri and several
other small cars I can't think of right now. A Buick-originated V8 design
was purchased by Rover in the 1960s and used in several Rover cars
and is still used in various models of the Range Rover plus I believe
some other British cars. Another good example of this is the Triumph
TR engine that originally was a tractor engine made by Standard, but
evolved over time and was used in Morgans, Loti, and numerous other
cars. Also the small-block Chevy V8 which has been in probably 100
different cars.

Bottom line: It's tough to design a good engine.

Doug.