Stock piston detonation.
 

I blew up my BP with speed6 k04 this weekend. I knew it was going to happen, but was expecting rods. Well i found extreme detonation/ melting on piston number three. No other pistons show any signs of detonation. My beliefe is that this was caused by lack of fuel in that one cylinder, most likely a clogged injector. Am i wrong thinking this?

https://www.miataturbo.net/attachmen...ine=1398794495

Niiiiiiiiiiiiiiice, what's the block look like?

Sound hypothesis.

cylinder walls are pretty messed up, ill add this is on intake side if that helps.

https://www.miataturbo.net/attachmen...ine=1398795449

https://www.miataturbo.net/attachmen...ine=1398795449

what is controlling your fuel?

Close up pictures of number four piston, please.

wait what?

He's using a K04 from a Mazdaspeed 6.

im intrigued, i always wanted to swap a k04 on my msm. my previous car was also a speed6 and i have alot of left over parts including a k04. ill have to look into this

That seems like a waste of time and money.

is this the same piece of crap k04 that has failing seals when you install exhaust and turn up the boost?

what in the world are those studs in the head?

I thought that was a Subie thing. They do the same on the Mazdaspeeds? That's fun.

The head bolts....

subie? subies have td04's not k04's. and they don't fail like this k04 pile of junk. dunno what you talkin bouts willis

Local subie autox guys are always blowing turbos. They're both shitty and have "04" in them, you expect me to know the difference?

yeah the k04's arent the best turbo, but it was cheap. Im using megasquirt pnp2 with rx7 460cc injectors. Ill get some more pictures next time im by the car.

the head bolts, lifted it off with the engine hoist since i already had the chain hooked up, left the bolts in the holes.

show us your spark table and logs of AFR

that piston looks like it was gangraped by a train of detonation.

Wow man, that things really fubar'd.

I'd send the injectors out to be tested and then cleaned if i were you. Do that and report back :)

I'll be impressed if we see a FaeFae Timing Map of Rape, but i think this is going to be a clear cut case of one injector failing out of an old shitty set of $40 RX7 injectors.

I gotta hand it to you, mckabe, that's one of the most impressively-destroyed pistons I have ever seen. We need a trophy on this site to commemorate that sort of thing. Until then, enjoy the avatar. :)

Seriously. He gets A+ for effort lol

$20 says the rest of the pistons show det damage on close inspection.

Yeah, I needed a reason to go forged any way. Bring on more boost. Injectors are going to get sent out next week.

Forged bottom end, more boost?

Time to just throw the 460s in the trash and get some good injectors.

YES!!!

EV1 injectors don't belong on a built engine. They belong in the trash.

you fabbed up your own manifold for the mazda flange? or did you just weld an adapter plate on an existing mani.

Curious is all.

I am curious to see the final diagnosis as my engine just let go a few days ago, I think in a similar manor.

let the hate begin: Ebay manifold, cut the flange off, re-welded with k04 flange. Added braces between both flanges and re-welded all welds. I haven't looked into injectors, but hell i might as well.

Look into the GT500 injectors, there are a couple of threads on them. That's probably what I'll use for my B2200 and eventually my miata.

sounds good, if im going forged, i might as well go all the way.

Yep, same POS. I've been debating replacing the one on my 07 Speed6 for the past year or so with aftermarket vs stock...

Right now the anti-mosquito smokescreen sucks any time I'm idling.

Some of the smoking issues were caused by the restrictor sizing in the banjo bolt being to large. multiple threads on mazdaspeedforums.

Forged pistons would have melted as well. Detonation kills everything. You would have burned up forged instead of stock. Get good injectors and maybe upgrade fuel pump. My motor blew and it had no detonation just rods flew out the block. After seeing this I will make sure I get good injectors and pump upgrade to e85.

I've never seen a road car piston that bad - I bet you've got det on the other pistons too though. Any close up photos of the combustion chambers and pistons from the rest of the block?

But it definitely looks like a fuel rail/injector issue - get some decent injectors before you spend on anything else.

Good luck!

Noob Question: With that much damage, wouldn't the detonation have been audible?

I would think it would be audible unless the exhaust is loud or the radio is being employed in a raucous fashion. Or if it was at very high speed.

Very, unless you don't know what detonation sounds like.