Broken V6 crankshaft

Post Reply
User avatar

Topic author
SafariRob
I sleep in my van
I sleep in my van
Posts: 556
Joined: Wed Sep 20, 2006 4:57 pm
Location: Bryan, Ohio, USA

Broken V6 crankshaft

Post by SafariRob »

I've heard that the 4.3 V6 has a weak crankshaft...never saw a broken one until now. This one is from a 1988 Astro.

Image

Can't say that this is a real problem to the vast majority of 4.3 engines, though. This crankshaft is from an engine that was dropped off at Bryan Engine Rebuilding and the business owner said that it's the first broken crank he's seen from a 4.3.
Rob Shaver
1989 Astro 305 with an MSD 6A ignition and a dash-mounted MSD timing control, a 4160 Holley 465 cfm four barrel carb, and an HEI distributor.
Moog 625 front springs and Energy Suspension poly bushings. Rear OEM sway bar. Edelbrock shocks.
User avatar

mdmead
I plan to be buried in my van
I plan to be buried in my van
Posts: 2153
Joined: Sun Sep 10, 2006 6:45 pm
Location: Selah, WA
Contact:

Re: Broken V6 crankshaft

Post by mdmead »

Hmm, that's the first time I've heard of one. Given the 4.3s running around with 150-200K+ miles, I guess it is a 'problem' we can live with! :muhaha:
Matt
Selah, WA
-96 GMC Safari AWD Hi-Top Conversion -->Stalled 5.3L swap & 5" lift
-74 Ford Bronco -->Far from perfect but mine!
-99 V-10 Ford Super Duty Super Cab 4x4 -->Stock with 285 Cooper ATs
-00 Ford Focus Wagon -->The Red Turd
-95 Ford 24' Class C Motorhome -->My big block sleeper
-07 Can-Am Outlander XT -->My yellow 4x4 quad for work & play
-04 Ski Doo REV Summit -->Still several chassis behind!


No new projects until the current ones are done!

astrozam
I have my van tatooed on my cheeks
I have my van tatooed on my cheeks
Posts: 2770
Joined: Fri Sep 08, 2006 2:57 am

Re: Broken V6 crankshaft

Post by astrozam »

I like the earthen backdrop contrasted nicely with the man made destruction, nice effect :supz:

Cobra
I plan to be buried in my van
I plan to be buried in my van
Posts: 1750
Joined: Sat Jun 16, 2007 2:31 pm
Location: Toronto, Ontario

Re: Broken V6 crankshaft

Post by Cobra »

I've never heard of the problem either....

Zam: it is a nice pic i'd use it as a background for my work computer
1998 GMC Safari AWD, BFGoodrich AllTerrain T/A
Jet performance tuner 91 octane preset, Jet under-drive pulleys
Rancho 999000 series shock, on-board controller to be installed later
DHC rock rails and skid plate Add-A-Leaf
G3500 front calipers
Zexel Torsen Diff
11" drums
180 amp Alternator
Long tru-cool 4590 trans cooler

1997 gone
User avatar

Smiliesafari
I have my van tatooed on my cheeks
I have my van tatooed on my cheeks
Posts: 2667
Joined: Sat Dec 02, 2006 12:34 pm
Location: Orlando, FL

Re: Broken V6 crankshaft

Post by Smiliesafari »

I'd like to know some history on that 4.3. You just don't see broken cranks these days. :-k
1996 Safari SLX Hotair balloon transport vehicle

Rebel
I plan to be buried in my van
I plan to be buried in my van
Posts: 2009
Joined: Thu Sep 14, 2006 7:24 am
Location: Evergreen, Al. 96 mile marker, where life is slow and there are no rules.

Re: Broken V6 crankshaft

Post by Rebel »

I like the earthen backdrop contrasted nicely with the man made destruction, nice effect
:muhaha:

Is very picturesque isn't it ?
Obviously a Fall crank event.
89 Astro, 350 V-8, Shaved doors, Filled Slider, Corvette IRS, 94 Mustang GT Rack & Pinion(Thanks to Skip), Cad Tail lights from SoCalliV8 ( RIP) Miss you my friend.

VIDEO

Image





If you drive illegally, they take your driver's license. If you're here illegally, they want to give you one :)












Image





If guns kill people, do pencils misspell words
User avatar

Topic author
SafariRob
I sleep in my van
I sleep in my van
Posts: 556
Joined: Wed Sep 20, 2006 4:57 pm
Location: Bryan, Ohio, USA

Re: Broken V6 crankshaft

Post by SafariRob »

astrozam wrote:I like the earthen backdrop contrasted nicely with the man made destruction, nice effect :supz:
Keith, you got me laughing out loud with that reply. Larry, you made me continue with the laughter!

All I know about this crank is that the guy who owned the van, which had high miles, was just out driving it normally and suddenly there was a lot of noise and the engine quit. That much I was told, but I'm sure he tried to start it. The starter gear would still engage the ring gear, but I bet the racket made while cranking told him that something was very, very wrong.
A couple of the main bearings were spun and one of the main bearing caps was gouged up pretty bad, but the block was okay. In fact, the block, heads and manifolds were used to build an engine that found its way into a 91 Chevy pickup truck.
Rob Shaver
1989 Astro 305 with an MSD 6A ignition and a dash-mounted MSD timing control, a 4160 Holley 465 cfm four barrel carb, and an HEI distributor.
Moog 625 front springs and Energy Suspension poly bushings. Rear OEM sway bar. Edelbrock shocks.

Rebel
I plan to be buried in my van
I plan to be buried in my van
Posts: 2009
Joined: Thu Sep 14, 2006 7:24 am
Location: Evergreen, Al. 96 mile marker, where life is slow and there are no rules.

Re: Broken V6 crankshaft

Post by Rebel »

I've heard that the 4.3 V6 has a weak crankshaft...never saw a broken one until now. This one is from a 1988 Astro.



Can't say that this is a real problem to the vast majority of 4.3 engines, though. This crankshaft is from an engine that was dropped off at Bryan Engine Rebuilding and the business owner said that it's the first broken crank he's seen from a 4.3.

_________________
Rob Shaver
1989 Astro 305 with an MSD 6A ignition and a dash-mounted MSD timing control, a 4160 Holley 465 cfm four barrel carb, and an HEI distributor.
Moog 625 front springs and Energy Suspension poly bushings. Rear OEM sway bar. Edelbrock shocks.




Top
Rob,,so now that's over with,,,what's going on in the far north. You up to another transplant bud or is this really someone elses tragedy ? :yawinkle:
89 Astro, 350 V-8, Shaved doors, Filled Slider, Corvette IRS, 94 Mustang GT Rack & Pinion(Thanks to Skip), Cad Tail lights from SoCalliV8 ( RIP) Miss you my friend.

VIDEO

Image





If you drive illegally, they take your driver's license. If you're here illegally, they want to give you one :)












Image





If guns kill people, do pencils misspell words
User avatar

Topic author
SafariRob
I sleep in my van
I sleep in my van
Posts: 556
Joined: Wed Sep 20, 2006 4:57 pm
Location: Bryan, Ohio, USA

Re: Broken V6 crankshaft

Post by SafariRob »

Larry,

No, that crank has nothing to do with me, I just had to get a photo and post it cuz I'd never seen one broken before and figured that you guys might not have, either. Like I mentioned, the owner of Bryan Engine had never seen a broken 4.3 crank before this one.
I'm still working slowly on the Chevy 350 rebuild for my 82 Olds Delta 88. Really put the emphasis on the word 'slowly' when you read that last line...There isn't much left to do on the 350, but it's a matter of making the time to do it. Finding the proper pushrod length is next on the agenda for the engine. Can't run the stock length as I'm using full roller rockers (steel ones from Comp Cams).
Replacing the engine is phase 1 for the Olds; phase 2 will be the installation of a 5 speed manual transmission. Just last Saturday I bought a 1984 305 Camaro Borg Warner T5 transmission and bell housing off of craigslist for the Olds. I had my heart set on a Tremec TKO 500 transmission but sure didn't have the $2000 plus for it. So spending $200 for the T5 appealed to me. The transmission seems fine, I just hope it'll slip into the Olds with minimum fuss.

By the way, the shift lever measures about 22.5 inches back from the bell housing lip. A quick and dirty measurement in the Astro tells me that this Camaro T5 would have its shift lever poking through the floor about even with the rear of the driver's seat if I were to install the transmission in the van. I've read that a T5 from an S-10 has the shift lever much closer to the front of the transmission. That would be a big plus in an Astro.
If you want to read my long, rambling postings concerning my Olds, you can go to CD Smalley's website, B-body.org, by clicking here.

Wait a minute! Did I just violate some forum rule?! Yikes! I beg mercy, O, Zammer!
Rob Shaver
1989 Astro 305 with an MSD 6A ignition and a dash-mounted MSD timing control, a 4160 Holley 465 cfm four barrel carb, and an HEI distributor.
Moog 625 front springs and Energy Suspension poly bushings. Rear OEM sway bar. Edelbrock shocks.
User avatar

SoCalli V8
Retired
Retired
I plan to be buried in my van
I plan to be buried in my van
Posts: 1209
Joined: Wed Sep 20, 2006 5:42 pm
Location: Lost Angels, Sovern KarlyFornia.

Re: Broken V6 crankshaft

Post by SoCalli V8 »

Smiliesafari wrote:I'd like to know some history on that 4.3. You just don't see broken cranks these days. :-k
Something else happened here, it looks like an oil stavation problem and spun a main journal bearing where the crank broke. Look how black that main journal is compared to the other silver ones, it got real hot.
`86 V8 Lowered Cargo, extensively modified, shaved bald, wearing the shortest, sluttyest white primer dress....

A British Wanker living in So KarlyFornia.
My Astro tows my toys to Glamis sand dunes http://www.youtube.com/watch?v=jp2pqjQtpso
First ever canal jump at Glamis http://www.youtube.com/watch?v=oXZjM84x_Xc
User avatar

Smiliesafari
I have my van tatooed on my cheeks
I have my van tatooed on my cheeks
Posts: 2667
Joined: Sat Dec 02, 2006 12:34 pm
Location: Orlando, FL

Re: Broken V6 crankshaft

Post by Smiliesafari »

I agree with you, Darren, about oil starvation. But it broke at a rod journal, not at the main. Very unusual to say the least. \:D/
1996 Safari SLX Hotair balloon transport vehicle

batmo
I sleep in my van
I sleep in my van
Posts: 264
Joined: Tue Apr 21, 2009 1:11 pm

Re: Broken V6 crankshaft

Post by batmo »

good observation socali!

it is discolored.. may have (most probably) spun the bearing first then heated up and snapped. it is also the weak spot in all offset journaled crankshafts. V8s included.

I used to do R&D for Buick Special Products Division, we tested for crankshaft flex/twist Ive seen cranks snap and engine blocks divide into peices right infront of me.. it was a cool gig. we made progress... dominated. then Buick was outlawed.

yes, nice backdrop for the photo ;-)
Post Reply