Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   If you know you spun a bearing clap your hands...Clap clap (https://www.miataturbo.net/diy-turbo-discussion-14/if-you-know-you-spun-bearing-clap-your-hands-clap-clap-38311/)

railz 08-20-2009 01:22 AM

If you know you spun a bearing clap your hands...Clap clap
 
Just about 350 miles in the new engine break-in and..:facepalm:

Im having my machinist inspect the m-tuned rod to see if its still usable.

Piston is trash and new one is on its way.

Head is also trash, no pics but the cam journals are completely shot with DEEP scratches all around, there goes $400 in head work down the drain.

Got a new head and had that worked on, just picked up from the machine shop today.
Sourced a perfect long nose crank and block for cheap($75).New ACL race bearings are here, full gasket kit and new rings are on there way. Re-using ARP hardware. Anything else?

bearing FAILURE pics VVV enjoy.

Good bearings on the left, Spun on the right
http://i28.tinypic.com/1zwhjj5.jpg
http://i25.tinypic.com/292oeoh.jpg
http://i26.tinypic.com/a3f2hd.jpg
http://i31.tinypic.com/b97gp.jpg
http://i26.tinypic.com/m9ajom.jpg
http://i30.tinypic.com/rj39y9.jpg
http://i31.tinypic.com/oh0ys.jpg

Savington 08-20-2009 01:59 AM

Throw that rod away. Throw everything away, actually. I woudn't reuse a single part from that motor.

Buy new parts, pay someone who knows what they are doing to assemble it. I just did my 3rd track day on my shortblock and it runs perfectly. Minimal blowby, burns no oil at all.

Edit: "Good on the left, spun bearings on the right" Both of those bearings are fucked. The left side is fucked; the right side is fucked.

crashnscar 08-20-2009 02:02 AM

Rod = fucked. Everything = fucked.

You so called good bearing on the left.... not so good.

Good job man.

railz 08-20-2009 02:03 AM

Sav, you got any kind of instant messenger?

PM me

Savington 08-20-2009 02:08 AM

AIM is the same as my screen name. Let's chat about getting a decent motor into your car.

JasonC SBB 08-20-2009 02:26 AM

Shit.
What was the root cause?

railz 08-20-2009 02:43 AM

dont know but somehow the bearing was starved of oil

New rods will have to be ordered..again

i haven't even paid off these rods yet through my credit card,fuck.

railz 08-20-2009 02:55 AM

i've gone WAY past my build budget so for rods im looking these. ETD is m-tuned right?

Mazda Miata 323 1.6 1.8 B BP H Beam Rod Rods:eBay Motors (item 190328220337 end time Aug-22-09 18:46:53 PDT)

They dont include the rod bolts but i still have them from the m-tuned rods

thesnowboarder 08-20-2009 03:35 AM

plastigage = ftw?

railz 08-20-2009 03:43 AM

seems like some of the debre from the piston rings break in might have clogged the oil passages for the bearings?

sighhhhh

Savington 08-20-2009 03:46 AM

?

railz 08-20-2009 04:05 AM


Originally Posted by Savington (Post 444428)
?

indeed

i have no clue :hustler:

ZX-Tex 08-20-2009 10:07 AM

Not sure about that theory on the piston ring debris. It would have to make it through the oil filter first.

oil sprays on bottom of piston and picks up debris -> oil and debris drip into sump -> pump pulls from sump -> oil goes through filter -> oil goes to main bearing.

wes65 08-20-2009 12:24 PM

Definitely some sort of oil starvation. That is scary. I am just now finishing my motor assembly. I did it my self and I've never done it before. I hope to god it doesn't end up like this. I think some root cause analysis is in order here.

CRXican 08-20-2009 12:44 PM


Originally Posted by railz (Post 444418)
dont know but somehow the bearing was starved of oil

New rods will have to be ordered..again

i haven't even paid off these rods yet through my credit card,fuck.

smart

ZX-Tex 08-20-2009 12:58 PM


Originally Posted by wes65 (Post 444557)
Definitely some sort of oil starvation. That is scary. I am just now finishing my motor assembly. I did it my self and I've never done it before. I hope to god it doesn't end up like this. I think some root cause analysis is in order here.

If that is the case, based on my experience, check the pressure relief valve on the oil pump.

neogenesis2004 08-20-2009 01:13 PM

Were any of your bearings on your mains on backward? That would cause starvation to a rod easily but not be noticed through oil pressure.

Well I guess your machine shop disassembled it so they wouldn't admitt a mistake they notice on disassembly anyway. The above is my best guess at the problem.

Cpt_Slow 08-25-2009 03:51 PM

(CLAP, CLAP)

I am still rebuilding mine. This has me freaked out that it's going to happen again during break-in.

Qckslvr 08-25-2009 04:12 PM

I spun a bearing in my 1875cc vw once. Forgot to put the dowel pin in the rear main journal. Ruined the case halves, and a 8 pin balanced stroker crank. All happened in under 5 miles. :( DOH!

Never did that again.

knock on wood I have yet to spin a bearing on a conventional bearing cap engine. :D

hustler 08-25-2009 04:34 PM

perfect, 300bhp motor crew signing in. Wisest car money I've spent in a while.


All times are GMT -4. The time now is 07:43 AM.


© 2024 MH Sub I, LLC dba Internet Brands