Help! SOS, I need a tow!

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Hot COCOAL

May the farce be with you
Jun 9, 2012
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RitzBlitz said:
I'd have to agree. Correlation does not equal causation. I'd venture to guess a lot of these trucks see the majority of driving with their cruise on. So of course more often than not many issues that arise will be during the time cruise is on.

In fact, I've made that same drive about 15 times over the past year (WA to Central Cal, even interviewed in Los Banos). Always in one shot. I would think that if something were to do my 200k+ mile motor in (with a large majority of those miles being with cruise on), that would do it if cruise caused it.

Unless injection events are significantly different under cruise, I can't see it being the main contributor to these failures.
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That's actually a very valid point, Josh, I hadn't taken that into consideration...
Well done.
LBZ said:
I know of over a hundred crank failures. And I'm sure there is more. My buddy at a gm dealer gets a couple every month and that's a small dealership.

I believe the main spin in this particular one was an after the fact. He never mentioned an oil pressure issue before the failure which tells me it didn't cause the break.
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Russ and I both believe the spun bearing happened after the fact.

malibu795 said:
He probably wouldn't have seen much oil psi drop. #1 is last to go get oil...
Idk how often Jason checks his gauges while driving..
I know for me when I lost my LB7 I have no clue how long it ran with a case full of fuel and it still did 35-40psi. Even after injector swap and fresh oil it was still "low" buy not below spec
Since then I have made it a habit to check gauges at least once every 60 seconds or so..
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I look at my gauges ALL THE TIME!!!
I had oil pressure even when the tach was bouncing around uncontrollably

I'm a Class A CDL holder, I drove for a living for several years, constant mirror checks and panning across the gauges is part of my multi-minute checks :thumb:

I may use the cruise contol (to avaoid getting tickets) but I'm far from a complacent and lazy vehicle operator/driver :D
 
fastpunker

fastpunker

adrenaline junkie
Feb 7, 2012
215
1
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Lake Havasu City, AZ
RPM Motorsports said:
Block is a boat anchor


7d6491b824e40905f1e692feba9e957f.jpg




Sent from my iPhone using Tapatalk
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Thanks for the close up pictures.... these have satisfied that part of my enjuneer brain. I would have to agree with the statements about the bearing failing after the crank break given the direction of the cheveron markings on the broken edges of the crank. I would think if the bearing failed first the break pattern would be more of a twist pattern... depending on what cylinder was firing at the time of failure. Fingers has done a lot more research and has way more knowledge than I do... so what do I know:dontknow:

Hot COCOAL said:
Better than golfing in Palm Springs could've ever been!
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Those pictures are priceless!!! Sounds like you have been able to turn the unfortunate event into bigger & better things and memories to cherish forever!!!! That'd be awesome to get it back as a Christmas present to yourself!! I am really glad to see everybody here stepping up and helping out in a time of need!!! Makes me happy to be apart of this community/group :thumb::hug:

DAVe3283 said:
If you don't edit the cruise tables, most of the tunes I've seen end up over fuelling compared to the normal throttle tables. I know on my LB7 I have my cruise fuel limit set at about 70mm3 to get it to drive normal.
Sent from my FlashScan V2
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DAVe3283 said:
The other difference I've noticed on cruise is the fueling can oscillate, especially on hills. It will be cruising at 30mm3 (or whatever), start up a hill, and start slowing down. Instead of adding more fuel quickly to avoid slowing down, it ramps in fuel slowly, then tries to "catch up" to the set MPH. Inevitably, it over shoots the speed, and ramps the fuel down too much, and repeats the process.

But you are right in that I've never seen it run differently on cruise (timing, pilot, etc. are all identical). It just gets stupid on hills, and wants to lug the motor to the point of smoking. I just turn cruise off and drive by foot on hills.
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I have noticed these problems with the cruise on my lb7 also. Any sort of hill to the slightest degree and I would watch the boost gauge fluctuate between 3-10ish psi. The slight accel/decel would drive me nuts so I would just turn it off. I was able to see the rail gauge increase and decrease a bit also, don't remember the figures though (as my stupid Autometer gauge is 15%off and they wont warranty it). It makes me wonder if GM had any kind of road load calculators, or tables, in their software like all of the cars do these days. :confused: We use these calculators all the time on the transmission side for shift scheduling/timing events and such.
 
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Burn Down

Burn Down

Hotrodder
Sep 14, 2008
7,092
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Boise Idaho
fastpunker said:
Thanks for the close up pictures.... these have satisfied that part of my enjuneer brain. I would have to agree with the statements about the bearing failing after the crank break given the direction of the cheveron markings on the broken edges of the crank. I would think if the bearing failed first the break pattern would be more of a twist pattern... depending on what cylinder was firing at the time of failure. Fingers has done a lot more research and has way more knowledge than I do... so what do I know:dontknow:
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They are not chevrons, they are beach marks. Chevrons are signs of a fast moving brittle fracture, beach marks are slower growing cracks. The tighter the beach mark the slower the crack grows.

All the broken cranks I have seen all start in the fillet of the crank. Slow moving fatigue fractures.
 
NC-smokinlmm

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
5,193
356
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At Da Beach
I need to stop reading broken crank threads...:mad:

They are gonna make me go buy a cummins next damit...:eek:

JK...:rofl: I would end up confused talking shit to myself at a stop light...:doh:
 
H

Hot COCOAL

May the farce be with you
Jun 9, 2012
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rickaveryjr said:
Glad to see you're making progress. Good buddy of mine just broke his crank at #1 about an hour ago.
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Thanks man, the parts list is almost settled...:rofl:
But, progress is progress, lol...Sorry to hear of your buddy's misfortune, as well, its not the most privileged experience... that's f'er sure

Pistons are in route and I ordered up the 625's today
Trying to squeeze a 12mm pump in/out of the budget this week too.

Really all I need to figure out is if I wanna try and twin it OR go with a bigger VVT and keep it as a single (I do miss the 72 and I'd love to check out the 68R) OR maybe I just be happy with getting it running cuz my budget is shot :broke:

Sure would like to get a cast, wagler intake and a set of HSP billet manifolds and 2" up pipes, too...I think we all know how it feels to want:eek:

;)
 
Burn Down

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
Hot COCOAL said:
Thanks man, the parts list is almost settled...:rofl:
But, progress is progress, lol...Sorry to hear of your buddy's misfortune, as well, its not the most privileged experience... that's f'er sure

Pistons are in route and I ordered up the 625's today
Trying to squeeze a 12mm pump in/out of the budget this week too.

Really all I need to figure out is if I wanna try and twin it OR go with a bigger VVT and keep it as a single (I do miss the 72 and I'd love to check out the 68R) OR maybe I just be happy with getting it running cuz my budget is shot :broke:

Sure would like to get a cast, wagler intake and a set of HSP billet manifolds and 2" up pipes, too...I think we all know how it feels to want:eek:

;)
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Does your hand smell like poop yet:D
 
H

Hot COCOAL

May the farce be with you
Jun 9, 2012
4,433
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0
Burn Down said:
Does your hand smell like poop yet:D
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(Sniff check) Ummmm, nope!
:confused:
That one went right over the top buddy, and I don't get it:roflmao:
Whattya mean, from pulling money out of my butt, or what...?
Havent gone there... yet:rolleyes:

My piggy bank probably needs some counciling tho
:spit:
 
Chevy1925

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,646
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Phoenix Az
Hot COCOAL said:
(Sniff check) Ummmm, nope!
:confused:
That one went right over the top buddy, and I don't get it:roflmao:
Whattya mean, from pulling money out of my butt, or what...?
Havent gone there... yet:rolleyes:

My piggy bank probably needs some counciling tho
:spit:
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"wish/want in one hand and shit in the other, see what one fills up faster" i believe is the saying he was giving you :D
 
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