Mar 21, 2017 update to the Mazda Miata project car

Our Turbo Miata Goes Boom

Don't worry, we made sure the road was safe and clean for others after we left our mark.
The smoking gun: All the oil marks in the engine bay appear to point toward the end of this oil hose that leads to the turbocharger.
We're also replacing all the suspension bushings throughout the car with parts from Energy Suspension.
A hydraulic press makes short work of suspension bushings.
We also have to replace our eBay coil-over sleeve setup (right) with stock Miata springs (left).

Racing wouldn’t be racing without constant setbacks. Nobody is immune to failure at some point in time, but if there’s one thing you don’t want to fail two weeks before a race, it’s the engine. See what we’re getting at?

After a flawless endurance race, our project turbo Miata gave out on us with the most inconvenient timing: while being moved between shops during our pre-race prep. That next race takes place in less than two weeks.

What happened? As best as we can tell, the oil line leading to the turbocharger failed and started spewing oil while we were driving the car. Unfortunately, the engine wasn’t hot enough to create an alarming plume of smoke. Just before we reached the second shop, we saw the oil pressure “gauge” drop to zero—remember, this year of the Miata doesn’t feature a proper oil pressure gauge as it’s really just an on/off idiot light connected to a gauge-like display. A few lessons have been learned here.

We immediately killed the engine, but after pushing the car into the shop and topping off the oil, our fears were realized: We still had no oil pressure. Our engine was done.

To confirm that diagnosis, we removed the oil filter and cut it open to see what it had caught. Though not much, there was definite evidence of copper. That was the final nail in the coffin.

Fortunately we’re armed with a backup engine. It’s a stock 1.8-liter from an automatic-equipped donor car. With a few late nights and some elbow grease, we hope to have the engines swapped in time to test the car at the FIRM this weekend.

While we have the car in the air, we are also making a couple suspension adjustments. First, we’re replacing all the suspension bushings with new parts from Energy Suspension. With a little help from a hydraulic press, this is a pretty straightforward (though time-consuming) process once all the control arms have been removed.

After that, we have to replace our eBay coil-over sleeve setup with stock Miata springs. This might be a performance downgrade, but we need to run stock springs in order to avoid incurring penalties at our race with ChumpCar at Daytona. Fortunately we can retain the Koni Shocks we’ve been running.

If everything goes according to plan, the car will be buttoned back up by the end of the week.

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Comments

View comments on the GRM forums
Keith Tanner
Keith Tanner MegaDork
3/21/17 1:07 p.m.

I can't believe that turbocharger outlasted the engine I run my car with both a proper gauge AND a big warning light hooked to the '96+ 7 psi switch. You can never make low oil pressure too obvious for a driver.

Stainless feed line?

Ed Higginbotham
Ed Higginbotham Associate Editor
3/21/17 1:13 p.m.

Very true, Keith. And yes, the feed line is a stainless braided line.

Woody
Woody MegaDork
3/21/17 1:14 p.m.

In reply to Keith Tanner:

Tell me more about this 96+ switch that I probably have two of in my basement.

NickD
NickD SuperDork
3/21/17 1:14 p.m.

And it didn't even get to go out in a blaze of glory, with connecting rods and chunks of block flying everywhere, just a relatively quiet death.

Ed Higginbotham
Ed Higginbotham Associate Editor
3/21/17 1:20 p.m.

In reply to NickD:

Yeah, this way may be less exciting, but at least we might be able to salvage most of it and rebuild it.

NickD
NickD SuperDork
3/21/17 1:24 p.m.

In reply to Ed Higginbotham:

That is also true. It's just kinda like when you break a bone doing something normal and you don't get a cool story out of it.

appliance_racer
appliance_racer New Reader
3/21/17 1:38 p.m.

I am (was) planning to stop by and say hi at daytona since I will be there wrenching for another team. If you need an extra wrench spinner please contact me. I'll have plenty of spare time and would love to help. Email me if you guys would like my phone#. I live in Orlando.

KyAllroad
KyAllroad UberDork
3/21/17 1:47 p.m.

Sorry to hear about your engine. That reminds me to replace my oil pressure sending unit with one from an NA6.

Of note: I just finished replacing my suspension bushings with the energy poly ones. Don't even try to push them out, you'll just get frustrated. Energy recommends (and I agree) using a torch and heating the old bushings till you hear them crackle but not actually burst into flame and then knocking them out with a punch (I used a 8" extension and a 22mm impact socket). They stink so good to do outside.

APEowner
APEowner Reader
3/21/17 1:52 p.m.
NickD wrote: And it didn't even get to go out in a blaze of glory, with connecting rods and chunks of block flying everywhere, just a relatively quiet death.

If I'm going to loose a race motor I want them to have to clean track the afterwards. This way is less expensive however.

Ed Higginbotham
Ed Higginbotham Associate Editor
3/21/17 2:06 p.m.

In reply to appliance_racer:

We'll see you there! Thanks for the offer.

NickD
NickD SuperDork
3/21/17 2:10 p.m.
KyAllroad wrote: Sorry to hear about your engine. That reminds me to replace my oil pressure sending unit with one from an NA6. Of note: I just finished replacing my suspension bushings with the energy poly ones. Don't even try to push them out, you'll just get frustrated. Energy recommends (and I agree) using a torch and heating the old bushings till you hear them crackle but not actually burst into flame and then knocking them out with a punch (I used a 8" extension and a 22mm impact socket). They stink so good to do outside.

I did it 2 winters ago. I pretty much had to set mine on fire. The garage stunk for 2-3 weeks afterwards.

Ed Higginbotham
Ed Higginbotham Associate Editor
3/21/17 2:10 p.m.
KyAllroad wrote: Of note: I just finished replacing my suspension bushings with the energy poly ones. Don't even try to push them out, you'll just get frustrated. Energy recommends (and I agree) using a torch and heating the old bushings till you hear them crackle but not actually burst into flame and then knocking them out with a punch (I used a 8" extension and a 22mm impact socket). They stink so good to do outside.

We actually had a fairly easy time pressing them out with a hydraulic press with no torch. But when I changed them on my personal Miata a couple years ago, we did have to heat them. Might depend on the state of the bushings.

Keith Tanner
Keith Tanner MegaDork
3/21/17 2:28 p.m.

I've always just pressed bushings out. I guess I didn't know how hard it was to do

Woody wrote: In reply to Keith Tanner: Tell me more about this 96+ switch that I probably have two of in my basement.

It's exactly that - an NO switch that closes at right around 7 psi. Put a tee on your sender and you get both a real gauge and an idiot light trigger. Hook it to a really, really, really bright LED aimed at the driver's optic nerve - or ideally, use it to reroute the ignition coil output to a couple of clips connected to the driver's testicles because drivers don't see lights.

FM has the parts needed. For the adapter, not the testicle clips.

APEowner
APEowner Reader
3/21/17 3:22 p.m.

I wonder if the testicle clip option would eliminate the "I saw the pressure was low but I thought it might make it till the end of the race" problem.

codrus
codrus SuperDork
3/21/17 3:32 p.m.
APEowner wrote: I wonder if the testicle clip option would eliminate the "I saw the pressure was low but I thought it might make it till the end of the race" problem.

That's just a question as to what's more important -- the engine or the trophy.

Keith Tanner
Keith Tanner MegaDork
3/21/17 4:16 p.m.

But usually what happens is you lose both...

1988RedT2
1988RedT2 UltimaDork
3/21/17 4:22 p.m.

"Turbo Miata goes boom?!" I had visions of broken engine parts and a spectacular failure and all I get is fake news.

rslifkin
rslifkin Dork
3/21/17 8:09 p.m.
1988RedT2 wrote: "Turbo Miata goes boom?!" I had visions of broken engine parts and a spectacular failure and all I get is fake news.

Yeah, I was picturing something like what happened when a friend decided to see just what the little turbo on his Volvo could do... Some E85, not enough timing retard and a plugged wastegate line later... Made it 36 hours of driving before it came to rest on the side of the road at the end of a 1/4 mile streak of oil and engine bits... He said he could hear parts of the rods bouncing off the floor pan when it let go

Knurled
Knurled MegaDork
3/21/17 8:32 p.m.
NickD wrote: And it didn't even get to go out in a blaze of glory, with connecting rods and chunks of block flying everywhere, just a relatively quiet death.

I seen a lot of busted motors but never one that sawed itself near in half before.

captdownshift
captdownshift PowerDork
3/21/17 8:38 p.m.

regarding a potential rebuild. KAI for rods boundary engineering for oil pump king bearings COP conversion modifed 4G63 intake manifold and enjoy the booooost

Ed Higginbotham
Ed Higginbotham Associate Editor
3/22/17 8:30 a.m.

Oh and last night we were pulling the engine and pressure tested that braided oil line leading to the turbo. It was blowing oil out just before the banjo fitting on the turbo end. So that was the weak link, not that it matters too much anymore.

NickD
NickD SuperDork
3/22/17 8:32 a.m.
Knurled wrote:
NickD wrote: And it didn't even get to go out in a blaze of glory, with connecting rods and chunks of block flying everywhere, just a relatively quiet death.

I seen a lot of busted motors but never one that sawed itself near in half before.

Step 1: Buy JB Weld

Step 2: Pull 1 degree of timing

Step 3: Schedule rematch

Keith Tanner
Keith Tanner MegaDork
3/22/17 10:42 a.m.
Ed Higginbotham wrote: Oh and last night we were pulling the engine and pressure tested that braided oil line leading to the turbo. It was blowing oil out just before the banjo fitting on the turbo end. So that was the weak link, not that it matters too much anymore.

Sounds like a bad crimp. Custom line from a local shop or from a Russel/Earls type source?

Ed Higginbotham
Ed Higginbotham Associate Editor
3/22/17 11:24 a.m.

In reply to Keith Tanner:

It actually wasn't at the crimp itself. it was an inch or two down the line.

Trackmouse
Trackmouse SuperDork
3/22/17 12:19 p.m.

Road debris?

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