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Blew the motor! Rebuild time.

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Old Jun 25, 2009 | 09:19 PM
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Default Blew the motor! Rebuild time.

Well, my motor blew today during a little cruise at lunch. My setup is in my sig..... 13 PSI on a SR20DET T25, stock 1.8L motor, megasquirt running a very conservative timming map (avg. of about 3 degrees more than DIY's base).

It blew when i was rolling into the throttle in first, maybe 4 or 5k RPMS, it had a sudden lurch, knock light lit up and stayed lit, I shifted into second and heard the MASSIVE tick.

This afternoon I pulled the valve cover off and everything looks normal, I drained the oil and strained it with a paint filter.... and amazingly it was perfectly clean!!!! So its not bearings. I'm kinda stumped. The motor will be out soon pending the weather holding out. Ill keep this updated.


I am just amazed I blew a motor with a t25 and a decent tune. It had 135k on it and even (but low) compression. It dynoed at 98 rwhp stock so it wasnt the most healthy motor.

Enough ranting, sorry for the horrible grammar.
Old Jun 25, 2009 | 11:26 PM
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Damn, that sux...
Old Jun 25, 2009 | 11:37 PM
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Do all your pistons still go up and down?
Old Jun 25, 2009 | 11:38 PM
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Sorry to hear. Well, another stocker bites the dust, and all the more reason for me to wait.
Old Jun 26, 2009 | 01:22 AM
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More reason for me to find a 1.8L and put these M-tuned rods in there. 200cc's is an extra 200cc's
Old Jun 26, 2009 | 06:44 AM
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Originally Posted by Savington
Do all your pistons still go up and down?
The thing runs, idles, and revs, but it is hurting, lol. It even sorda drives ( i was forced to drive it 1/4 mile back to work so i could get a tow after work) Just for ***** I will do a compression test today.
Old Jun 26, 2009 | 08:57 AM
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Originally Posted by sbkcocker499
More reason for me to find a 1.8L and put these M-tuned rods in there. 200cc's is an extra 200cc's
yep, and worth every cent for the rods and pistons.
Old Jun 26, 2009 | 09:03 AM
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Originally Posted by hustler
yep, and worth every cent for the rods and pistons.
i want to upgrade to a 1.8 as well, but its more than just the price of the engine.
new manifold, MS, wiring harness.
Old Jun 26, 2009 | 09:06 AM
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Originally Posted by tyson87
i want to upgrade to a 1.8 as well, but its more than just the price of the engine.
new manifold, MS, wiring harness.
Manifold, yes. MS and wiring harness, no. Your 1.6 wiring, sensors, and computer will work just fine on the 1.8 engine. Upgrading the MS to an MS2 would be optional if you went with an NB block & head.
Old Jun 26, 2009 | 09:09 AM
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Originally Posted by Joe Perez
Manifold, yes. MS and wiring harness, no. Your 1.6 wiring, sensors, and computer will work just fine on the 1.8 engine. Upgrading the MS to an MS2 would be optional if you went with an NB block & head.
hmmm, i didnt know that.
its time for me to start searching....
Old Jun 26, 2009 | 09:16 AM
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Well that sucks. I need to get a decent tune into mine so it will last until I get a new one.
Old Jun 26, 2009 | 09:20 AM
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Originally Posted by tyson87
hmmm, i didnt know that.
its time for me to start searching....
then either get a job or start sucking. I'd rather have a built 1.6 than a stock 1.8 though.

Just ****** up a blow bottom 99 motor and go from there. I had a 28k mile motor for mine and I'm happy I opened it up and went with forged guts.
Old Jun 26, 2009 | 09:49 AM
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Originally Posted by 240_to_miata
I am just amazed I blew a motor with a t25 and a decent tune.
A weak motor is a weak motor. I put a freshened cylinder head on a very tired bottom end for an ITA Miata. That head made the car a full 2 seconds a lap quicker. But I knew that extra (compression) power was only going to stress the bottom end. Sure enough, 3 laps to go in the enduro (our last race of the weekend), while running in second place, the engine spun a bearing. And that was w/o boost.
Old Jun 26, 2009 | 12:36 PM
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damn this makes me nervous! Even though my motor has still less than 10k on it (prolly less than 6k). Its still only built to stock specs.

How many boosted miles did you last?
Old Jun 26, 2009 | 07:04 PM
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Damn, kind of scares me.
Old Jun 26, 2009 | 07:58 PM
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3000 miles.... was gunna change the oil this weekend. Its still raining here, so the motor isnt out yet.

Compression test results (No spark plugs, throttle wide open, cold motor)...

175, 50, 175, 125

Something is up....
It was about 175-180 all around when i installed the turbo.
Old Jun 27, 2009 | 01:39 PM
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Definitely going to keep following this thread...Let us know what you find out!
Old Jun 27, 2009 | 01:48 PM
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Originally Posted by tyson87
hmmm, i didnt know that.
its time for me to start searching....
how could you not? Its the most rudimentary basic information for anyone with a 1.6.
Old Jun 27, 2009 | 02:23 PM
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What octane gas did you have in there?
Old Jun 27, 2009 | 06:10 PM
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sonoco 93 octane



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