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1G 1gb 7 bolt crankwalk?

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Compound1g

Proven Member
58
1
Feb 10, 2019
Qualicum beach, BC_Canada
Not sure if this is the correct subform to post this in

I just finished building my 1gb, put about 1000km on it and starting having clutch disengagement issues, had a couple other issues such as oil leaks, so I pulled the motor out and found the thrust bearing was completely destroyed, and killed the thrust surface on the crank as well. Before the rebuild, the motor had 220,000km on it and never had cw issues so I don't understand why it walked in just barely 1000km, I pulled the crank and put a newer one in, but before I did that, I ran the pump with a drill and primed to system to ensure that oil was getting to the mains properly, and it seems to be.
Now, I've setup a compound system using a 16g and the stock turbo, seems to work well, I used the stock oil line from the head for the stock turbo, and ran a line from the OFH for the second turbo, I was thinking that maybe having two lines would be pushing too much oil, and limiting how much gets to the mains, does that make sense?
Oil pressure always seemed low, but the stock guage sucks and I don't know exactly what my pressure is, but with the balance shafts eliminated, it should read higher than the first mark at 6k rpm, but it always read low, not quite sure why, it's a new oil pump as well so thats probably not an issue. Anyway, I just want it make sure it won't cw again, but I'm not sure exactly why it did to begin with
 
You need to get an oil pressure gauge so you aren't assuming what your oil pressure is. My pressure is what I'd call on the "lower" side: 15psi hot idle, 75psi @ 7k RPM, no balance shafts and heavily ported oil relief. My stock gauge reads about 50% @ 7k rpm.

You also need to make sure all your block and crank oil passages are clean and all the crap is out of them.

It's possible the stock crank had alal of left over gunk in the oil passages and it let loose after you did the rebuild. There's not a great way to get the stuff out without removing the balls , cleaning, then putting in new plugs.

You also didn't say what the clearance was on any of your rod/mains.

Does your block have oil squirters? If so, what style are they? Just wondering if the block was swapped before you got the car maybe.
 
Did your block's thrust surface suffer any wear or get out of spec when the thrust bearing got ate up?
My son's block even ruined THAT surface as well as the crank.
@tametalon92 has some very good questions about clearances that could lead to the reason it walked and also the fact that we all need a REAL oil pressure gauge to go by also.
 
Sorry, I wrote this post last night, forgot to include some info

I initially bought the car with a blown head gasket, then found out it had a Spun bearing, so I tore it down, had the crank machined, put a new head, revised lifters, etc, I plastigaged it and all was within spec, and yes, I cleaned out everything as best I could before reassembly.
The block is definitely a stock 1g 7 bolt, with 1g squirters, I cleaned them and reinstalled them.
The thrust bearing and crank got destroyed, but it never reached the block, got close though.
An oil pressure gauge is next on my list
 
I'm betting on there being left over crap in the crank then, and maybe low oil pressure contributing still. Do you have any pics of the said bearing and crank? We might be able to help deduce if the failure was from contamination or lack of oil. Any pics would help.

I'm also curious about your compound setup, do you have or could you post more info/pics on how yours is set up?
 
Just from my experience. When the car started to have the clutch disengagement issues, did you try the extended clutch slave cylinder rod or/and shim the clutch fork pivot too much? If too much that may cause the crankwalk on 1G 6/7 bolt, especially if the oil pressure is low. My 1g 6 bolt got the crankwalk long time ago because of that.
Another possibility is maybe you cranked too long with the clutch pedal depressed.
 
Grabbed a couple pictures
I had the flywheel machined, and I believe that messed up the step height too much, it's probably been machined before, but I had forgotten, when I first started it up (clutch switch disconnected) I had to crank for a while because the IAC and fiav had been bypassed and you had to push the pedal to give it enough air to start, I didn't know and just kept cranking (stupid, I know)
Anyway, I shimmed the pivot ball so the fork sits right in the middle
 

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As @tametalon92 and @1990TSIAWDTALON mentioned that you need a good oil pressure gauge.
Just in case, are you sure that two balance shaft oil holes are blocked properly? This is very common that forget to block the oil holes for balance shaft. and two oil holes are wide open then cause very low oil pressure.
 
As @tametalon92 and @1990TSIAWDTALON mentioned that you need a good oil pressure gauge.
Just in case, are you sure that two balance shaft oil holes are blocked properly? This is very common that forget to block the oil holes for balance shaft. and two oil holes are wide open then cause very low oil pressure.
Yes, I'm positive I got them blocked correctly, I'll hook up an oil pressure guage and see what it's doing
 
Yes, I'm positive I got them blocked correctly, I'll hook up an oil pressure guage and see what it's doing
Just my another thought, could be oil starvation in oil pump? Badly smashed oil pan or blown oil pickup gasket? Do you have the oil pressure switch functioned?
 
You can T that line and put a switch back in if necessary. Just fyi.
Here is how my balance shaft bearings sit in my blocks without balance shafts.
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Is the switch even needed?
And ya, that's about what my bearings look like, I rotated them 180 degrees

The switch is far more useful that the factory gauge IMHO. It will tell you if the oil pressure dips below the factory spec, which is 4 psi IIRC. I have mine on, and even when my oil pressure gauge dips to 10psi on a idle dip in hot weather, when the fan comes on it'll show as low as 6 psi, and my oil dummy light (switch) still doesn't come on. That's only happened once when it was 102 out and I had driven about 250 miles back from Seattle.

I still have my factory gauge hooked up too, but it's pretty worthless, my innovate gauge is what I trust.
 
Ok, just finished getting the motor back in the car and hooked up, I teed off the oil line from the head into both turbos, and removed the second line I added.
Immediately oil pressure sits about 1/4 from the bottom (used to sit at, or almost at the bottom) and at 3k it's just above the first mark, on the factory gauge, I'll get an aftermarket one on soon to confirm actual pressure.
I only ran it till warmed up cause its cold, and snowing here haha, ill check for leaks and drive it around tomorrow
 
The thrusts are mainly splash oiled, its not likely a pressure problem that caused that, a poorly adjusted clutch or a heavy clutch plate on a crank that doesnt have the proper surface hardening in that area would be most likely.
 
The thrusts are mainly splash oiled, its not likely a pressure problem that caused that, a poorly adjusted clutch or a heavy clutch plate on a crank that doesnt have the proper surface hardening in that area would be most likely.


All of what you just said is what I dealt with initially, I had the crank cut .50mm due to the Spun bearing, they may have "cleaned up" the thrust surface.
clutch was not properly adjusted at all for the first start, due to the step height issue from machining the flywheel, so that, coupled with the act 2600, may have just been too much for it? I'll have to drive it a bit and see what it does
 
The thrusts are mainly splash oiled, its not likely a pressure problem that caused that, a poorly adjusted clutch or a heavy clutch plate on a crank that doesnt have the proper surface hardening in that area would be most likely.

Not to contradict directly, but the thrust is fed after the main bearing, not what I'd call "splash" fed, just down stream. While it may not be solely a pressure issue, low pressure or volume to the main, and then the thrust bearing, could still be a primary cause.

Since the OP said the crank was cut, it's possible the low pressure was accentuated due to large thrust clearance, loss of hardened surface and a heavier pressure plate.

Either way, there are several factors that are relevant to the failure.
 
Not to contradict directly, but the thrust is fed after the main bearing, not what I'd call "splash" fed, just down stream. While it may not be solely a pressure issue, low pressure or volume to the main, and then the thrust bearing, could still be a primary cause.

Since the OP said the crank was cut, it's possible the low pressure was accentuated due to large thrust clearance, loss of hardened surface and a heavier pressure plate.

Either way, there are several factors that are relevant to the failure.
The point I am making is that its not a pressure fed surface.
 
The point I am making is that its not a pressure fed surface.

I can agree with that haha. Wasn't trying to be nitpicky, I just hear "splash lubed" and I makes me think of breaking in a sbc cam or rear axle bearings.
 
Figured I should follow up
I've put about 100km on it now, popped open the filter and found some black debris (probably gasket material from when I cleaned the off the front cover gasket)
And almost no metal, so I think it should be ok now

However, I've been chasing a pinging issue since I first got this thing going

It has a custom tuned chip, converted to use a map sensor (with no translator, it's weird, it shouldn't run this way, but works great), has an iat, tuned to run 10 Afr under boost, 560cc injectors, stock boost gauge setup to read knock, and probably a few other things

It runs about 20 psi boost, and holds it from about 3500 rpm right to redline, but it starts pinging once it hits anything over around 10, the gauge shoots up to about halfway and the ecu starts pulling a ton of timing, but it's not always predictable, sometimes it pulls timing at 8 Psi, and sometimes at 15, is it just phantom knock?

I added a water-meth (injecting from 8 psi, and all in at 15) kit thinking it would help, pulls like a bat outa hell, but still pulls timing at 8-12 psi. I'm thinking about pulling the sensor and doing some testing with a headset and sensitive microphones, might help to tell if it's phantom knock or not, any suggrsugges on this?

It just seems weird to me, it was running 20 psi before the build, with no knock issues, now it's got 8.5:1 Cr (vs the stock 7.8:1) and I can't even run 10 psi? Doesn't make sense, any thoughts?
 
It just seems weird to me, it was running 20 psi before the build, with no knock issues, now it's got 8.5:1 Cr (vs the stock 7.8:1) and I can't even run 10 psi? Doesn't make sense, any thoughts?
Did you set the base ignition timing correctly? Isn't it too advanced?

I added a water-meth (injecting from 8 psi, and all in at 15) kit thinking it would help, pulls like a bat outa hell, but still pulls timing at 8-12 psi. I'm thinking about pulling the sensor and doing some testing with a headset and sensitive microphones, might help to tell if it's phantom knock or not, any suggrsugges on this?
As for knock monitor, you really need a good knock monitor that has a realtime monitor function and a good headphone that shuts the noise from outside. But to do that you need an assistant who drives a car. Or connect a knock monitor output to a laptop to record the sounds from knock monitor and pass the audio file to high/low-pass filter to analyze.
 
Throw some E85 in the tank and see if the pinging goes away. I couldn't run 4* without the knock sensor pulling timing.
On E I could run 19*. Night and day difference.
What ever you do, don't disregard the sensor.
 
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