General Miata Chat A place to talk about anything Miata
View Poll Results: When will it it blow?
Next time you drive it/any minute now!
5
20.00%
First track day
1
4.00%
In another 5,000 miles
5
20.00%
More than 20,000 miles
9
36.00%
Forever as long as you learn how to shift!
5
20.00%
Voters: 25. You may not vote on this poll

So how long will my stock NC motor last

Old 12-14-2009, 09:02 AM
  #1  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Question So how long will my stock NC motor last

Maybe we should do an official pool to see

as some of you saw in the dyno day thread it put out 283 whp on my "conservative" tune with peak timing of like 13 degrees at 7k.

Since then I dropped it down two more degrees and added a bit more fuel without any noticeable loss in power (11-11.5 AFR), and put in two baffles in the muffler to slow down the boost creep (jumped to 14 psi at 20 degrees last week!).

Currently running 8psi to 4k, 10 psi 4-7k rpm. Peak torque is ~230 or so vs 140 stock.

For those who don't know the 06-08 NC motor has 10.8:1 compression, all cast internals. Motor was overrevved at least twice at the track with a 4 to 2 money shift last year prior to boost. (hit the same damn bump at the etown straight right at the 3-4 shift point!) Compression numbers were 210 dead even on all 4 just prior to turbo.

It's my second car so I only drive it to beat the crap out of it...in other words, if it was human it would be tiger woods. It has a few auto-x events on it, some 'local' drifting, and will see a track day or two again next year, some official drift events, and maybe hill climbs. About 41k on the car, 4k with boost.

At this point I'm torn--do I build the motor before it blows or let it die a natural death? I know honda guys run their hi comp cast motors to 10+ psi with few issues when actually tuned, with the duratec focus/mz3 crowd usually blowing trannys first, but they supposedly only go to 260 hp or so.
I'm thinking to just ride it till it blows since they are so damn common and cheap. Then I can just pick up a low mileage block and get forged internals and not have to worry about boring and honing. Poll only goes to 20k because that would take two years for me to do if not more and by then I'll definitely be building it.

This is the car...
mann is offline  
Old 12-14-2009, 09:10 AM
  #2  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,490
Total Cats: 4,079
Default

Brian's has seen lots of track duty and it running over 300rwhp right?
Braineack is offline  
Old 12-14-2009, 09:11 AM
  #3  
Elite Member
iTrader: (12)
 
Doppelgänger's Avatar
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,850
Total Cats: 71
Default

2.3 block swap?
Doppelgänger is offline  
Old 12-14-2009, 09:15 AM
  #4  
Elite Member
iTrader: (9)
 
Saml01's Avatar
 
Join Date: Jul 2007
Location: NYC
Posts: 5,710
Total Cats: 3
Default

Great editing. Awesome numbers.
Saml01 is offline  
Old 12-14-2009, 09:25 AM
  #5  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Default

Brian's has seen track duty from what he says but I'm not sure how much total driving he's done with it since its trailered and certainly not cali-legal. His dyno showed 260 or so IRC...

2.3 swap--it would be easy as they bolt right up. It's a more common block too as ford used it in every 4 cylinder from 2005 up. 2.5 from the current gen of duratecs might work also but I'm not sure.

saml01--thanks still learning premiere its a bear I need a 1080p cam instead of my canon point and shoot
mann is offline  
Old 12-14-2009, 09:27 AM
  #6  
Elite Member
iTrader: (12)
 
Doppelgänger's Avatar
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,850
Total Cats: 71
Default

Is the constructions of the 2.3 internals any different than the 2.0L ?
Doppelgänger is offline  
Old 12-14-2009, 09:36 AM
  #7  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Default

the turbo disi 2.3 has forged rods and pistons but those mazdaspeed motors are not holding up too great far above 300whp from what I hear.

the na 2.3 has cast junk. If I had to do it now I'd get a forged crank from mazda motorsports, and run wisecos with eagle rods.
mann is offline  
Old 12-14-2009, 09:41 AM
  #8  
Senior Member
 
airbrush1's Avatar
 
Join Date: Nov 2005
Location: Baltimore Maryland
Posts: 1,038
Total Cats: 9
Default

I say pick up a spare motor and start your build now... that way if and when your stock motor dies a horrible death, you have less downtime.
airbrush1 is offline  
Old 12-14-2009, 09:42 AM
  #9  
Elite Member
iTrader: (12)
 
Doppelgänger's Avatar
 
Join Date: Sep 2007
Location: Charlotte, NC
Posts: 6,850
Total Cats: 71
Default

I suspect the MS cars aren't running good tunes because the ECUs are teh suckage.

Is the 2.3disi short block the same as the normal 2.3?
Doppelgänger is offline  
Old 12-14-2009, 09:49 AM
  #10  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Default

Originally Posted by airbrush1
I say pick up a spare motor and start your build now... that way if and when your stock motor dies a horrible death, you have less downtime.
I know, I should...just being lazy
Originally Posted by Doppelgänger
I suspect the MS cars aren't running good tunes because the ECUs are teh suckage.

Is the 2.3disi short block the same as the normal 2.3?
short blocks are the same...just balance shafts crank rods pistons and heads that are different.

I don't know what goes on with their tunes but on the NC I can dial in whatever timing I need and fuel so I'm not too concerned there. I suppose with bigger than 550's and more than 15 psi there might be issues since the resolution is only like 13 rows and load based vs. map but so far its fine no knock.
mann is offline  
Old 12-14-2009, 12:17 PM
  #11  
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,482
Total Cats: 372
Default

Originally Posted by mann
I'm thinking to just ride it till it blows...
second car = just do it
Just keep an eye out for a stellar deal on a build engine while driving on this one. IMO less boost is less fun.
m2cupcar is offline  
Old 12-14-2009, 12:28 PM
  #12  
Elite Member
iTrader: (28)
 
p51hellfire's Avatar
 
Join Date: May 2008
Location: St. Augustine FL
Posts: 2,299
Total Cats: 2
Default

look at the IM mani at 2:23 I think I saw a jump of electricity lol or something ....
p51hellfire is offline  
Old 12-14-2009, 12:51 PM
  #13  
Elite Member
iTrader: (51)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Spring, TX
Posts: 7,257
Total Cats: 26
Default

That is one NICE torque curve....flat as a table.
gospeed81 is offline  
Old 12-14-2009, 07:59 PM
  #14  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Default

Originally Posted by p51hellfire
look at the IM mani at 2:23 I think I saw a jump of electricity lol or something ....
that's the exhaust manifold (opposite on NC)

No idea how or why but that's a fireball from between the turbo and manifold. Really odd as I was taping that I thought "**** was that a flash in the corner of my eye" and then I saw it on the video.

It's weird because the turbo is on there tight, I used an SS gasket and if you put your hand there you don't feel any exhaust leak. There was also no knock or anything weird on the logs for that run either. No soot on the block or that general area. Maybe just from running rich while spooling up until all the air gets flowing at full boost?
mann is offline  
Old 12-14-2009, 08:00 PM
  #15  
Junior Member
Thread Starter
 
mann's Avatar
 
Join Date: Dec 2006
Posts: 54
Total Cats: 1
Default

Originally Posted by gospeed81
That is one NICE torque curve....flat as a table.
yeah I keep thinking of that picture in someone's signature about cake and eating it too
mann is offline  
Old 12-14-2009, 08:05 PM
  #16  
Senior Member
iTrader: (3)
 
miataspeed2005's Avatar
 
Join Date: Jul 2005
Location: Connect-I-Cut
Posts: 1,404
Total Cats: 0
Default

IMO it will throw a rod tomorrow.







JP
miataspeed2005 is offline  
Old 12-14-2009, 08:06 PM
  #17  
Elite Member
iTrader: (12)
 
neogenesis2004's Avatar
 
Join Date: Aug 2006
Posts: 4,413
Total Cats: 20
Default

yeah I keep thinking of that picture in someone's signature about cake and eating it too
That would be y8s, mayor of noobville.
neogenesis2004 is offline  
Old 12-14-2009, 08:19 PM
  #18  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Originally Posted by mann
Then I can just pick up a low mileage block and get forged internals and not have to worry about boring and honing.
This is terrible, terrible, awful logic. Built motors are bored to match the set of pistons you supply the machinist, and then they are honed to match the rings. (something about the material or design, not exactly sure what, but my machine shop wanted a set of rings both times.) Do not think for a single second that you can buy forged internals and shove them in a low-mileage block without machine work.

Build your motor now, because when it throws a rod through the side of the case and bends a few valves, you'll have to shell out for a new shortblock.
Savington is offline  
Old 12-14-2009, 08:27 PM
  #19  
Elite Member
iTrader: (4)
 
MartinezA92's Avatar
 
Join Date: Aug 2009
Location: Redwood City, CA
Posts: 1,784
Total Cats: 42
Default

Originally Posted by Savington
then they are honed to match the rings. (something about the material or design, not exactly sure what, but my machine shop wanted a set of rings both times.)
This.
The walls have to be honed with a certain grit stone according to what type of rings you have. IMO, if whoever is honing your block doesn't ask for your rings or at least what material they're made out of, you need a new machinist.
MartinezA92 is offline  
Old 12-14-2009, 08:57 PM
  #20  
Junior Member
iTrader: (34)
 
harleybutter's Avatar
 
Join Date: Oct 2007
Location: Garner, NC
Posts: 269
Total Cats: 0
Default

While it still runs, and I hope it does for some time, take your time to find a high mileage 2.0L or 2.3L and rebuild. It is cheaper when you are not in a rush to build it.
harleybutter is offline  

Thread Tools
Search this Thread
Quick Reply: So how long will my stock NC motor last



All times are GMT -4. The time now is 07:10 PM.