Dead Engine Autopsy (picture intensive) - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Engine Performance This section is for discussion on all engine building related questions.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 07-22-2010, 05:18 PM   #21
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,896
Total Cats: 109
Default

You have a detonation problem on all 4 cylinders clearly. Those clean spots on the piston edges and ridges are not good. I would rule out the coolant reroute, and concentrate on tuning issues. I think you have the timing way to hot.

When you pull the pistons, report on how much tension you have in the rings. Over heating would make them weak, and you will notice cylinder wall scuffing and piston scuffing. Detonation will not necessarily have an affect on ring tension. Over heating will.
miata2fast is online now   Reply With Quote
Old 07-22-2010, 05:46 PM   #22
Senior Member
iTrader: (8)
 
Join Date: Feb 2009
Location: Jax, Fl
Posts: 907
Total Cats: 0
Default

Quote:
Originally Posted by wayne_curr View Post
Your detonation doesn't look nearly as bad as mine did though.
Got ya beat
Name:  100_0354.jpg
Views: 0
Size:  107.8 KB
johnmatt is offline   Reply With Quote
Old 07-22-2010, 06:38 PM   #23
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,878
Total Cats: 1,790
Default

Braineack is online now   Reply With Quote
Old 07-22-2010, 06:54 PM   #24
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

You pussies don't even know what det is...

Name:  930c50d3.jpg
Views: 0
Size:  108.3 KB

Name:  708abca2.jpg
Views: 0
Size:  127.4 KB

Name:  7ce84d1a.jpg
Views: 0
Size:  81.5 KB
gospeed81 is offline   Reply With Quote
Old 07-22-2010, 07:17 PM   #25
Elite Member
iTrader: (30)
 
Join Date: Aug 2007
Location: Va Beach
Posts: 7,282
Total Cats: 0
Default

You ******* need to learn how to tune lol.

<- hopes to never eat those words.
__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
levnubhin is offline   Reply With Quote
Old 07-22-2010, 07:43 PM   #26
Elite Member
iTrader: (8)
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,732
Total Cats: 3
Default

This should all be making Mr. Ganger feel better about his engine.

Name:  DSCF0498.jpg
Views: 0
Size:  124.5 KB
wayne_curr is offline   Reply With Quote
Old 07-22-2010, 07:48 PM   #27
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

lol @ pushing it and not finding the conservative happy place.
hustler is offline   Reply With Quote
Old 07-22-2010, 09:46 PM   #28
90R
Junior Member
iTrader: (4)
 
Join Date: Jul 2010
Posts: 278
Total Cats: 0
Default

why do #1 & #2 rods have rust on them?

is the head flat?
90R is offline   Reply With Quote
Old 07-23-2010, 12:13 AM   #29
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by hustler View Post
lol @ pushing it and not finding the conservative happy place.
My tune was conservative, for me. Water injection, Brainy's advance dialed back a few degrees...

You know who killed mine, you met him. Let him borrow it over Christmas break and he brought it back smoking.


New tune will be higher resolution MS2, crank trigger, and real, new injectors. Water injection soon to come, just missed a good deal from Sav, but eyeing splittime's setup.




Dopple, I'm in to see where your tuning went wrong as well. I thought my timing advance table was gravy, but you can see from the above there were some bad spots in it that ate up the motor during consecutive pulls (although he said he was eating up STis and such and having fun, so oh well).
gospeed81 is offline   Reply With Quote
Old 07-23-2010, 12:54 AM   #30
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

Well, it was tuned by a VERY respectable tuner here in GA. The guys tunes TONS of stuff...everything from carb'ed turbo cars, to SPEED challenge cars, to Spec Miatas, to high-strung all motor Hondas. I trust him. Actually, I was running that tune since a month after I bought the car. Tracked it, drove it across the country, daily'ed it...everything. Something happened pretty quickly..as in within a couple of weeks before the failure. I'm almost wondering about a bad tank of gas that I got the week before at some podunk station in Alabama.

Cylinder walls are perfect and the cross-hatching is visible as it should be. No scoring, gouging or scratches at all.
Doppelgänger is offline   Reply With Quote
Old 07-26-2010, 11:44 PM   #31
Junior Member
iTrader: (2)
 
Join Date: Dec 2009
Location: Louisville, KY
Posts: 232
Total Cats: 0
Default

How many miles did you have on that setup again? I think it was a lot if I remember right
AutoFreak57 is offline   Reply With Quote
Old 07-27-2010, 12:00 AM   #32
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

FWIW, I wiped the carbon off the pistons tonight and found some small pitting on #1 and #2 by the exhaust valve area but not much on #3 or #4.

Edit- fuckit here are pics of the pistons with a little rubbing off...

piston #1



#2 on right #3 on left



#2 close



cross-hatching



#4


Last edited by Doppelgänger; 07-27-2010 at 12:23 AM.
Doppelgänger is offline   Reply With Quote
Old 07-27-2010, 12:24 AM   #33
Senior Member
iTrader: (14)
 
Join Date: Aug 2008
Location: Tinley Park, IL
Posts: 1,488
Total Cats: 0
Default

What about air temps? I've seen the hottest AITs ever in my car during this never ending heat wave. Yesterday was the nicest day we've had in two months up here.

I agree with the above mentioned thoughts as well. 1&2 look bad and the#1 rod does look bent. Don't be surprised if the ring lands fall off of #1 when you pull it. Post that spark map anyway, inquiring minds want to know.
lordrigamus is offline   Reply With Quote
Old 07-27-2010, 09:28 AM   #34
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,672
Total Cats: 1,561
Default

So Doppelganger, do you think the reroute with the 01+ headgasket was the primary problem or do you think your tune needed less spark advance when IATs get above a certain threshold as was proposed by Lordrigamus?
sixshooter is online now   Reply With Quote
Old 07-27-2010, 09:55 AM   #35
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

I think it was the reroute. Seems the lack of flow around the topend on 1 & 2 indeed caused excessive heat/detonation. I will be adding a front t-stat and plumbing to my reroute very shortly.
Doppelgänger is offline   Reply With Quote
Old 07-27-2010, 10:15 AM   #36
Elite Member
iTrader: (2)
 
miata2fast's Avatar
 
Join Date: Aug 2009
Location: Dover, FL
Posts: 2,896
Total Cats: 109
Default

I have my doubts about the reroute. All four pistons look like they have been in a tumbler. That is not a overheating issue That is many miles of fun.

Let's face it, a boosted engine that is beat on is not going to come out unscathed with stock pistons forever. Even with a conservative map.
miata2fast is online now   Reply With Quote
Old 07-27-2010, 10:16 AM   #37
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

Quote:
Originally Posted by lordrigamus View Post
What about air temps? I've seen the hottest AITs ever in my car during this never ending heat wave. Yesterday was the nicest day we've had in two months up here.

I agree with the above mentioned thoughts as well. 1&2 look bad and the#1 rod does look bent. Don't be surprised if the ring lands fall off of #1 when you pull it. Post that spark map anyway, inquiring minds want to know.
Quote:
Originally Posted by sixshooter View Post
So Doppelganger, do you think the reroute with the 01+ headgasket was the primary problem or do you think your tune needed less spark advance when IATs get above a certain threshold as was proposed by Lordrigamus?

I don't have a map on my work computer, but I do have a 1st-4th gear pull .csv log where you can see what my timing was doing under boost
Attached Files
File Type: zip 1st 2nd 3rd 4th run 2.zip (3.6 KB, 27 views)
Doppelgänger is offline   Reply With Quote
Old 07-27-2010, 10:18 AM   #38
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

Quote:
Originally Posted by miata2fast View Post
I have my doubts about the reroute. All four pistons look like they have been in a tumbler. That is not a overheating issue That is many miles of fun.

Let's face it, a boosted engine that is beat on is not going to come out unscathed with stock pistons forever. Even with a conservative map.
True, but there is obviously more issues with 1&2 where it's known that the design of the 01+ HG reduces coolant flow significantly.
Doppelgänger is offline   Reply With Quote
Old 07-27-2010, 01:14 PM   #39
Elite Member
iTrader: (2)
 
fooger03's Avatar
 
Join Date: Jan 2009
Location: Columbus, OH
Posts: 4,132
Total Cats: 187
Default

Just out of curiosity, you weren't the one that posted a recent vid of your car hitting 26 psi, were you?
fooger03 is offline   Reply With Quote
Old 07-27-2010, 01:21 PM   #40
Elite Member
Thread Starter
iTrader: (12)
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,868
Total Cats: 66
Default

nope, not me.
Doppelgänger is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 04:23 PM
1991 special edition with hard top full part out JC, NJ russian Miata parts for sale/trade 6 10-08-2015 04:01 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:30 AM.