Windowing a block is overplayed?

BC847

BC847

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May 14, 2006
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Engine block's lube-oil pump recess . .

Crack-in-Oil-Pump-Recess---LEFT_zpsoxvubohp.jpg



Front-Crankshaft-Bearing-Block-Webbing-Cracked_zpsfuqccts6.jpg



On the way in to see which cylinder/rod-bearing is stomping around.

Crap. :doh:
 
Impressive.

Sent from my motorola one vision using Tapatalk
 
Wonder if the initial cause is the crank broke ?
 
Ouch David.

Check breakaway torque on your rod cap bolts, out of curiosity, if nothing else.
 
What we have here is a 27ish year old stock/OEM short block with 295,502 miles on it. I've pretty-much drove the **** out of it. A lot of the typical Thursday night Test-N-Tune followed by a trip to the coast the following Friday over the last ten years.

'93 5.9 12V. Well flowing head (195in/220out), 188/220 cam, recently two S362 into one S362 (150ish lb/min). 12mm VE w/working dynamic-timing, honed 5x.018 (4.7ltr/min). All the other mess.

Cranked it up to go and make a dyno appointment. Noticed the oil pressure was a little lower than normal. Oil level good. On the way home I heard what initially sounded like I'd air-bound an injector (it's a VE thing). Within a moment, that apparent miss turning into a very pronounced stomping in the block. No oil pressure. Oil level's still good.
The engine still ran. The hardness of the stomp followed the throttle.

I'm initially thinking a rod bearing parted ways but, it does look like the crankshaft was trying to get out.

Taking things apart, I did notice the gearcase cover's crankshaft seal appeared like it was severely wallowed-out with a corresponding very wide groove in the associated speedy-sleeve on the crankshaft.

Still got to pull the engine to see inside.


The back-pressure always appeared very reasonable. Being very critical of it, it's always spiked a little with letting off the throttle just after a good pull. Otherwise, the back-pressure matched/lagged behind the boost.

If you can make it out:
- Orange is engine RPM.
- Purple is that seen at the secondary's outlet.
- Lt Blue is back-pressure

rpm-secondary-backpressure_zpsbbrkkl0a.jpg
 
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Gear-case mount.

WTH_zpsksyxfqaa.jpg





From that in the lube-oil pump recess all the way back to the turbo lube-oil return port.

From-Oil-Pump-toTurbo-Oil-Return_zpsmhqnnbfb.jpg




Still pulling it apart. :bang
 
That thing was on the verge of splitting the block at the main studs. Just means you gotta go bigger now!
 
I had just set up the dyno appointment for a week ahead. The thought was that would give me a week to identify and address any stupid stuff beforehand (a known issue in my past).

Anyhoo, I'd just finished a new transmission build and, I'd just realized that I could program the Compushift to have the OverDrive and converter lockup below 35MPH (for the dyno). So, rolling along locked, in OD at 35MPH, and holding the brakes, I built the boost up to 25psig and let it eat.

Then it went to stomping. :doh:
 
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Edit, see the setup now.

Am I reading the graph right that the excitement happened below 1k rpm?
 
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BC847 said:
It's my understanding that the '93 5.9 12v has 14mm mains stock/OEM.
Click to expand...

12mm or 14mm doesn't really matter, it looks like the block split above where the top end of the main studs are located. I have seen a number of blocks split at the same location.
 
bateman said:
Edit, see the setup now.

Am I reading the graph right that the excitement happened below 1k rpm?
Click to expand...
That particular plot is just to illustrate the boost/back-pressure relationship. ;)

Typically, I'm around 2000 engine RPM @ 25psig boost as the lights come down.
 
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