I've Really Killed My MX-5 This Time, So This Is The New Grand Plan

My famous little MX-5 has been through the mill lately, and this time, it looks like Phil's engine really is dead. So here's my new grand plan...

Alex Kersten

25 Aug 2016

If you’ve been following the popular Project MX-5 series on our YouTube channel, you’ll know that Phil, my trusty, turbocharged steed has had a tough time of it in recent months. After getting turbocharged and gaining almost double the power, a lot of extra strain has been put through the old 1.8-litre BP-ZE engine, which resulted in blown oil seals while at the Nurburgring and general rough running.

After rescuing Phil from the ‘Ring and getting the seals replaced, boost pressure was then upped (see video above) and I drove away (with a very angry-sounding clutch) with over 250bhp at the crank. ‘Great’, I thought, ‘this is now one of the fastest MX-5s in the country’. (Not the fastest by any stretch of the imagination, but still damn quick).

Well, after trying to start little old Phil up the week before last, I heard a loud bang coming from under the bonnet, which sounded as though a heavy piece of metal had fallen to the ground and through my heart like a Hummer-punch that inextricably imploded my world, tied me up and buried me underground with 100kgs of TNT, a lighter and 10 crocodiles that hadn’t eaten for 1000 years…

The engine cut out immediately, and since then, Phil has been in hibernation. Again.

252hp at the crank was eventually too much for Phil to handle...

Until my buddy Gareth and I strip the engine and take a look, I won’t know what the damage is, to either the engine or the turbo. But one thing’s for sure: Phil is/was/will be again my daily and I’m all through with him being less than reliable. So there’s only one thing for it…an engine swap!

Tom's Turbo Garage: LS3 V8 Miata Build - Project Thunderbolt

So then, what are my options? Well, V8 swaps are popular, but I don’t fancy going down that road, partly because of our insane fuel prices (did you know that we pay approximately $9 per gallon in the UK?!), coupled with the fact that the MX-5’s fuel tank is pretty small, meaning more regular fill-ups, and ain’t nobody got time for that!

You guys are also crying out for me to look into a rotary swap, which would keep the car Mazda pure, but again, it’s not something that grabs me because reliability and smooth running is very important to me.

What does really appeal to me is a six cylinder engine. Naturally, a BMW M52 2.8-litre engine is right up my street, but without cutting into the firewall and massive fabrication, it’s not feasible on a budget.

Could the MX-6's 2.5 V6 be Phil's new heart?

After some digging on the internet and conversations with MX-5 friends, I’ve discovered that a Mazda-sourced V6 would work very nicely indeed. The 2.5-litre KL engine as fitted to the Mazda MX-6 and Ford Probe GT would also keep the car in the Mazda bloodline, and would provide great power (around 200hp), reliability, and an engine and exhaust note sweet enough to do really bad things to.

Here’s a short video of one such car that already has the V6 swap, to give you a little taster of what may be coming to the Project MX-5 series in the next few months…

So to all of you who ask me how Phil is and what the plan is, this is your answer. Obviously, however, it’s very early days, but I’m excited at the prospect of maybe having a V6 MX-5 as a daily.

What are your thoughts, and what other options should I consider?

Comments

That Mazda V6 is a lot of motor for a miata. I think it would be a rocket.

I like how he said that an I6 will be hard to put in and yet people still comment about I6 swaps. xD

Audi 2.7 bi-turbo from the B5 S4 and various C5 A5s. They come with a super strong longitudinal gearbox (you have to weld the centre diff though and it’s not difficult to turn the exhaust manifolds around so they point forwards to make extra room. They’re about £1000 for a full setup. 2K will buy a whole car. Standard turbos with a remap give 330bhp and 380lbft. Remote mount a single turbo in front of the engine to make extra room and you can run 500bhp 500lbft without opening up the block, just injectors, intercooler, fuel pump and appropriate map. The standard Bosch ECU fully supports launch control and flat shift and multiple maps too. Why more people don’t use these engines I’ll never know. They sound immense too.

(Copy-pasted from a facebook comment)

I love the V6 into Phill. Besides, a newer more sophisticated and high tech engine will go in the line of reliability and fuel economy. How about a 4 cylecoboost?

What about Honda k-series? 4 banger 2 litre, 200hp, capability to make much more from it. I think i saw somewere kit’s for this swap

How about a VW VR6 engine? More compact than an inline 6 or V6 (shorter than an I6, slimmer than V6) also lighter than a V6 due to the fact it has fewer parts. Only real issue I can foresee is that they the metal between the cylinders is not as thick, and therefore not as strong, and the I6 and V6 so forced induction at high boost pressures could be out of the question.

Smooth and reliable can be had with a rotary engine out of an FC or FE so long as it is properly oiled and cooled. You can have one that’s basically brand new for less than $3500 in the states and given how many rx8s sold in the UK, it couldn’t be that hard to find a similarly priced one there.