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-   -   I think i blew my engine. (https://www.miataturbo.net/general-miata-chat-9/i-think-i-blew-my-engine-28443/)

gianic 11-22-2008 09:18 AM

I think i blew my engine.
 
Hello,
Yesterday I did something really stupid. I raised my boost up to 17 psi and at 4th gear ,WOT and 6k rpms my car felt that it lost some power.
After I pulled over I heard a weird sound like knock knock knock continuesly but no smoke from the tail. The sound is coming from the upper place of the engine.
I found some oil in the oil catch can but not much.

After a quick thought I drove the car towards a friendly garage and the engineer ensured me that something is broken inside the engine, just hearing this awful sound. When i drove the car i noticed that in high rpms the knock knock gets weaker and weaker but lots of white smoke comes from tailpipe during acceleration. Also there is a huge power loss but the turbo still produces boost.

What do you guys think I ruined, except my day and my wallet ?

paul 11-22-2008 09:54 AM

maybe blew a hole in a piston or fuxored a ring or valve.

Braineack 11-22-2008 10:14 AM

1 Attachment(s)
Attachment 209895

paul 11-22-2008 10:19 AM

Just out of curiosity, why would you turn the boost up to 17psi with an EMB and 305cc injectors?

gianic 11-22-2008 10:22 AM


Originally Posted by paul (Post 333163)
maybe blew a hole in a piston or fuxored a ring or valve.

If that its true , is it from the power or the poor management ?

I ran 11:1 the moment it failed without knocking.

paul 11-22-2008 10:24 AM


Originally Posted by gianic (Post 333176)
If that its true , is it from the power or the poor management ?

I ran 11:1 the moment it failed without knocking.

My sig can answer that question.


How are you maintaining an 11:1 AFR at those boost levels with 305's? I don't see anything about an AFPR.

gianic 11-22-2008 10:30 AM


Originally Posted by paul (Post 333177)
My sig can answer that question.


How are you maintaining an 11:1 AFR at those boost levels with 305's? I don't see anything about an AFPR.

I dont use an afpr, these readings are what zeitronix was showing. I guess that either the injectors are underrated or zeironix doesn't show up the right values.

paul 11-22-2008 10:42 AM

My vote is against the supra injectors being underrated by that much. Did you happen to be logging when this happened?

gianic 11-22-2008 10:47 AM


Originally Posted by paul (Post 333182)
My vote is against the supra injectors being underrated by that much. Did you happen to be logging when this happened?

Unfortunetaly no. My eyes was centered at the a/f zei gauge during the failure and my afrs were from 10.5 to 11.7:1.

Braineack 11-22-2008 10:48 AM

Do you have 255HP fuel pump? All I've heard about the '99 is the lack of maintaining fuel pressure in high RPMs without one.

Coupled with 305cc injectors, it is impossible with the stock fuel system to support more than 230BHP. ...that's only around 195rwhp.

If your wideband was at 11:1, then your tune had major issues where you could not make a lot of power even with a shit ton of boost. So poor ignition timing, restrictions, extra heat, etc.

The noise you hear is more than likely your ringlands bouncing around.

gianic 11-22-2008 10:57 AM


Originally Posted by Braineack (Post 333184)
Do you have 255HP fuel pump? All I've heard about the '99 is the lack of maintaining fuel pressure in high RPMs without one.

Coupled with 305cc injectors, it is impossible with the stock fuel system to support more than 230BHP. ...that's only around 195rwhp.

If your wideband was at 11:1, then your tune had major issues where you could not make a lot of power even with a shit ton of boost. So poor ignition timing, restrictions, extra heat, etc.

The noise you hear is more than likely your ringlands bouncing around.

I m pretty messed up with my failure and i forgot to mention something.

After 5k rpms the boost keeps dropping and dropping and dropping until 6 psi at redline. My bad. Sorry I think this is the reason that my afrs are good up there.

paul 11-22-2008 11:22 AM

well now it makes more sense. Duty cycle is a lot lower at 5k then it is at redline. I can see 305s running an 11:1 AFR at 7k at only 6psi.

gianic 11-22-2008 11:30 AM

From your experience Braineack and Paul do you suggest me to reinforce the engine with forged internals or just repair it with stock parts?

And something else. Idle runs rock solid at 900 rpms, And car revs freely.

johndoe 11-22-2008 11:35 AM

I would read a bit more if I were you #1. It depends on what your goals are. If you want 350+ you should build the motor. Below that the stock block can handle it with a good tune. Either way if you do some stupid shit like this again you'll blow your shit up. So read.

gianic 11-22-2008 11:45 AM


Originally Posted by johndoe (Post 333193)
I would read a bit more if I were you #1. It depends on what your goals are. If you want 350+ you should build the motor. Below that the stock block can handle it with a good tune. Either way if you do some stupid shit like this again you'll blow your shit up. So read.

I feel so damn noob. When I was building the car I promised to my self that i wouldnt run over 12 psi. I hold my promise until the time I installed the incabin mbc shit.. That was my disaster!

Braineack 11-22-2008 12:31 PM

right now you should do a leakdown test to determine what failed exactly.

m2cupcar 11-22-2008 12:47 PM

If you can't keep a promise to yourself, then you definitely need use forged parts on a rebuild.

gianic 11-22-2008 01:29 PM


Originally Posted by m2cupcar (Post 333216)
If you can't keep a promise to yourself, then you definitely need use forged parts on a rebuild.

That would be wise and cost effective in the future :)

Brain i m seeking right now the posts for the tests.

gianic 11-25-2008 10:55 AM

7 Attachment(s)
Right now I have this. Tomorrow i ll post and the rods condition. Any recommendations accepted.

Attachment 209863

Attachment 209864
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Attachment 209869

gianic 11-25-2008 10:56 AM

Sorry about the quality guys its from my mobile.


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