Did I blow my motor?

[Leiden]

I started with the Greddy Turbo basemap with the Standard Injectors which I slightly adjusted for Turbo Spool RPM's. It ran a little rich, I.E. bogging at about 4500rpm's and missfire, I leaned it around 20% and it stopped missfiring, ran good.

I switched to the 540CC Caldina injectors, I had to pull 37% fuel from the entire fuel map, but instead of the exact 37% I decided to pull only 32% just incase, so it was running 5% richer off boost, and on boost with the 540CC injectors (340/540 = 37% difference)

As for knock I guess theres not much point then, the sample time from the emanage is only 20ms so it doesnt look like it would have enough scope to read knock

The thing is with the stock ecu still reading the knock if the stock ecu detects too much knock then it will put the engine into limp mode and the check engine light will come on, that didnt happen! So I dont get it...

So yea, thats how I got here...

Whats the best way to tell if its a snapped ring, if I dropped the sump and reached up into the bore would I be able to move the piston around slightly with a snapped ring?

[sergei]

Whats the best way to tell if its a snapped ring, if I dropped the sump and reached up into the bore would I be able to move the piston around slightly with a snapped ring?

Compression test is the easiest way with minimal disassembly.
You will not be able to see the broken ring unless it was catastrophic failure, any way you would notice that with all the seals being blown out as well as smoke screen like you are running lada engine...

[Leiden]

Just did the compression test, engine about half up to usual temperature on the guage:

#1: 192psi
#2: 199psi
#3: 192psi
#4: 175psi

Low on number 4, could it be the damaged ring theory?

[sergei]

Just did the compression test, engine about half up to usual temperature on the guage:

#1: 192psi
#2: 199psi
#3: 192psi
#4: 175psi

Low on number 4, could it be the damaged ring theory?

I would expect it to be in 50-100psi range if chunk of ringland was broken off, with 175Psi it is probably small crack... although that difference could be caused by worn bearing as well...

[Leiden]

You mean a worn bearing on the conrod?

Would a cracked ring cause that much knocking? What about a ring that has split in half but still in its ringland?

[sergei]

Rings are made out steel, while ring land out of alloy, it is highly unlikely for ring to break. As for the knocking noise, the conrod bearing will cause that.

[Leiden]

Ah ok,

Eliminated the Alternator and P/S Pump by removing the belts, removed the coils one by one while it was running and the sound remained the same and constant,

So check the conrod bearings by pulling the sump and checking for play, could I also check the upper conrod bearings or will that be a mission? Wouldn't it be a more deeper throaty sound for a conrod bearing?

If the ringland was cracked why would it cause a knocking? Piston moving at TDC?

What if a valve had something stuck in the surface where it seals, could that make a knocking and slightly lower the compression on that cylinder?

[sergei]

There is no upper conrod bearing, just a bronze bush in the conrod (or similar) and steel floating pin, these don't move as much and usually don't wear out. The conrod bearing will cause sound coming from the head area because piston will hit the head (there is only head gasket thickness clearance between piston and some parts of the head).
Suck valve will result in really low compression.
The cracked ring land will not make any mechanical noise unless it has been dislodged along with broken piston skirt and some of it is in the sump - this failure will cause complete loss of compression as piston is completely disintegrated and is a hand grenade without a pin.

From what it looks like you have worn bottom end bearing and/or cracked ring land, detonation can cause these things.
Having a thinker head gasket does not help with detonation BTW, it actually worsens it.

[Leiden]

So I just have to drop the sump, check for metal shavings, and then check the conrod bearing for play,

I understand about the squish and that the thicker gasket can mess up the quench pads ability to work, but it was only an extra 0.8mm, enough to drop the compression to 10.5:1 because I wanted to run 12psi

[allencr]

I think one was about 0.4mm but that wouldnt make such a loud sound would it?
Its not a deep tapping, quite tinny really, like a rattling headshield sound...

YES it would, being about twice its normal clearance!
Does it sound about 1/2 engine speed?

[Leiden]

I'll have to check the timing of the sound, but that would definately help pinpoint if its the block or the head!

[MAGN1T]

I know it's a Toyota but in my experience destroying Mitsubishis....... you should be running it on 98, you should also have at least a Knock Link to monitor knock.
When the factory ECU (generalisation) detects knock it tries to retard timing, it also floods the motor with fuel. That's the black smoke. The noise will be the ring and ring land going up and down where the ring land is no longer supporting the ring. The plug will get oil on the threads soon.It'll probably drive perfectly OK for ages but you'll end up with a groove in the bore.

I did the exact same thing on Manfield several years ago, bit of detonation coming out of a corner, a cough , black smoke, rattle then it flooded out and stalled.... had to be towed off the track.

Steve

[rollaholic]

yeah i was gonna say i would have thought 98 would be mandatory

some people get pinking on their NA 3S engines with 95

10.5 compression and 12 psi...

[Leiden]

I have noticed oil on the #4 plug threads, just assumed it was from taking the camshaft cover off and a bit of remaining oil dripping down the hole,

I usually notice a little oil on the coils which sit directly on the plugs, so you think if I cleaned off the oil on the threads, reinstalled the plug and removed it after running the engine it would have oil on it?

If there was oil in the cylinder then wouldnt it be blowing blue smoke, nothing comes out, not even a puff of the black smoke...?

When I did look down the plug hole on the top of the piston it looked wet, got a sample from it and it seemed thinner than oil more like unburnt fuel, probably from cold start enrichment?

[Leiden]

Found some flakes of something in the sump, not entirely sure what they are from? Conrod bearing gone bad?

[sergei]

It looks like the conrod bearing (bits of it), did you feel any play in it?

[Leiden]

Couldn't get up to the crankshaft, the sump pan is small and sits before the cross member so I'll have to jack the motor up and remove the whole sump assembly which bolts to the bottom of the block and gearbox!

[Leiden]

Oh and that gold blob about the size of a 5c piece is actually where the paint has flaked off due to bottoming out the sump, its not a little pool of metal flakes

[Leiden]

Project car anyone? Just sick of this car...

http://z4.invisionfree.com/lexusaltezzaclub/index.php?showtopic=8078

[molex]

10.5:1, 12 psi and no tuning. It lasted HOW long?

Seriously, testament to toyota reliability it didn't just detonate itself to pieces first time you drove it. After spending x number of thousands on a turbo kit, why on earth didn't you spend another $100 on a fueling run on a dyno? Hell, just finding somebody with a wideband (I would have done it) in exchange for a box of piss.

Having said that, you're best off to pull down the motor and check out all the possibilities, it's down on compression but not by a huge amount. If it were a cracked ringland I would be expecting a fairly noticable increase in blowby/smoke out the breather, do you have a catch can?