Miata Turbo Forum - Boost cars, acquire cats.

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- - Motor blew lastnight (https://www.miataturbo.net/general-miata-chat-9/motor-blew-lastnight-45962/)

Quote:

Originally Posted by gospeed81 (Post 552939)

Ouch...what kind of bike was it?

I completely missed this question..

Back in 2004 I bought a 1994 Ninja ZX6 that was in really great condition and only had like 7900 miles on it. Thing looked good and ran like a top! The guy I made the mistake of letting ride it didn't do too much damage in the grand scheme of things..

Still have the same bike but it hardly runs now and still looks like complete shit. :mad:

My piston and rod were completely, utterly shredded and I was able to reuse the head. The crank was reusable too. Both were checked by an excellent race engine shop and approved for further service.

Like Magna said though you will not know until you get the engine out and tear it down for inspection.

Sorry to hear that...Now its time to build that killer motor !!!

At least the head didn't eat shit.

Since it was ticking prior to explosion, does that suggest the wrist pin got sloppy before it gave way?

I thought the weakness in the stock rod was in the actual rod...

Quote:

Originally Posted by Joe Perez (Post 645745)

http://img38.imagefra.me/f387ak/re7i_992_u77ts.jpg

You need to put a cat in there joe.

I dont want to sound like the dumbest shit here:loser:,but how many miles did that powerplant have at moment of self destruction,and how many miles were in boost.......want to go boost in AFRICA here,but this scared me into different religion. All that @ 6psi:facepalm:

Sorry about your loss.....:2cents:

Quote:

Originally Posted by jbresee (Post 645742)

Since it was ticking prior to explosion, does that suggest the wrist pin got sloppy before it gave way?

I thought the weakness in the stock rod was in the actual rod...

The wrist pin and where it holds to the piston is intact. I would say the rod let go first, unless the piston skirt managed to some how fall off?

What RPM did you run the motor to? Was it ever downshift-overrevved?

A number of people have seen rods fail days or weeks after an overrev, at a fairly low speed. As I understand it, an overrev can damage the rod such that it will fail after a short period of fatigue from use at normal revs.

--Ian

Looks like moderate detonation damage on the last picture of the piston (the close-up). Suxorz.

Quote:

Originally Posted by oldschool (Post 645920)

Yeah, me too. I'd like to know the millage/boost/internal modifications to any exploded 1.6 engine.

I have a 1.6 with 200k on it that seems to be healthy. My original thought was to build a stock 1.6 before installing the turbo (something like a BEGI S4, 5psi), but several people have told me, "Fuck it, just boost the engine you have." After seeing this thread now though...I have to wonder of these same people telling me I don't need a fresh engine are the ones who are just really too used to blowing shit up.

LMAO. Thanks Joe, got a really good laugh from that. Only thing would've been better if a chicken/duck were inside.. :D

No clue how many miles on it, probably 10,000 after I put it together. This was my junkyard escort/miata hybrid. Block, rods, pistons had around 200k, crank had around 140k, bearings were new when I assembled. Measured it all with micrometer and the werks so tolerances were great. Had maybe 3500 miles of boost, most of those were with a weak fuel pump and total shit AFRs, stock injectors, stock fuel rail, rising rate regulator.

Never did downshift overspin it, but the motor did live a REALLY terrible life. Since it wasn't a daily driver I abused the thing pretty heavily, and honestly I take full responsibility for the failure. 100% my fault.

Two weeks prior to the failure I was out beating on it racing around with some friends and it developed a slight tick that could only be heard under steady state throttle above idle. Idle, acceleration, deceleration it was completely silent. Checked the oil and appeared to be a little low, maybe 1/2 a quart at the absolute most. Judging by the crank journal we're pretty sure it met demise from a spun rod bearing.

Oh well. Had a spare motor in my garage that ended up being locked up (rusted..) that I actually paid 250$ for. Went to the junk yard and grabbed another escort motor to discover my 10,000 mile cylinder head has badly burnt exhaust valves and the rings are pretty weak on the block. To be honest I'm not sure I even want to mess with this car anymore as I'm losing interest in it very quickly. :sad2:

Ok, I guess I'm not so worried then :) While my engine is old and worn, my management and tune will be a lot better (if I can help it).

Well if u claim responsibility,its yours mate:facepalm:.I have about 80k on my 1.6 and it will be tuned professionally,but IMHO were all guilty of passing the red line on the revcounter now or then.:jerkit:

Youre pics made me think of maybe doing the 323 gtx rods and wisecos,just not to ass rape my block,is it worth it and will it be "safer" then?:hustler:
:noob:Really did scare me to shit:vash:

Don't forget, my motor is also a BP 1.8 liter, not a 1.6..

Check out those 949Racing chinese H-Beam rods.. they look really quality and get good reviews!

Lmk if you decide to get out. I need your megasquirt.