Tuesday, October 23, 2012

Miniature Marvel - Mazda 1.8 Liter V6 Dream Build

Mazda's K8 was a teeny tiny 60° V6 displacing only 1.8 liters, first introduced in 1992.  The only car this little gem ever saw service in State-side was the MX-3 of the nineties, a small FWD sporty hatchback styled like some sort of deep-sea submersible - wasn't everything then?  The MX-3 was reportedly a lot of fun to drive, but it was a bit too soft, a bit too feminine to be taken seriously as an affordable sports coupe.

so 90's it hurts

Its little V6 heart, though, was anything but cuddly.  While not big on power (130 HP in US spec, 144 HP in its ultimate JDM evolution), it was long on impressive specs - four bolt mains, DOHC per bank, 24 valves and all-aluminum construction.  Conservatively redlined at 7,000 RPM with a fuel cutoff 500 RPM later, they've been known to rev much higher with perfect reliability, thanks in large part to its oversquare architecture (75mm bore, 69.6 stroke) and previously mentioned four bolt mains.


Recently I started thinking about a no expense spared ultra-build NA K8.  Starting with intake, I'd fit port and polished heads with big valves, high-lift cams and individual throttle bodies - these would bring huge improvements to breathing and throttle response.  Inside the block, some forged high-comp pistons and H-beam rods in conjunction with the stock forged crank would bring further gains.  Custom headers, a full exhaust and of course a stand-alone engine management system running uprated injectors would round out the package.  Since we're spending Monopoly money here, let's throw in a dry sump too.  Good, semi-realistic fantasy numbers for the little beast would be 200 HP @ 9,000 RPM - I'm no engineer though, just a geek with a dream.

look how cute!

Now that we know what kind of meat we're working with, what kind of sandwich do I have in mind?  Why, an NA Miata, of course - as they're fond of saying over at Jalopnik, "Miata is always the answer".  Hooked up to a six speed and placed longitudinally into an MX-5's relatively huge engine bay, I can't imagine any insurmountable packaging issues, and with similar dry weight to the 1.8 four fitted from factory, no untoward affects on handling either.

= fun
Even stock, the K8 would offer roughly equivalent performance to the NA's standard four, in addition to a lot of multi-cylinder sophistication and a truly exotic soundtrack - these things positively sing through a nice aftermarket exhaust.

Taking the full-on race engine nutter bastard option, in the end, after a ton of effort, money, and time, you'd end up with a $25,000 Miata with the performance of a nice, used $12,000 S2000 - but I've always been a firm believer in the old adage that you can't put a price on style, and what on Automotive Earth would have more?


  1. I believe that all the K-series V6s share external dimensions. So, really, the 2.5 from the 626 would swap easily, AND the JDM version made 200-hp. I don't know if there are any KL-ZE (that's the Japanese version with 200hp) engines left to import, but it wouldn't require a lot of extra work and probably wouldn't weigh much more.

  2. I always thought it'd be fun to bolt one of these engines into a Protege or 323 of some sort.

  3. http://www.youtube.com/watch?v=ocQ_R5MO7Vc

    1. Super-cool. What a sound that little V6 makes with those ITB's.