It went boom! - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 05-10-2005, 01:37 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,088
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
It went boom!

Sometimes things don't work out. The inspection process is as important as the assembly it elf. This engine took a set of dart pro 1's with a late 60's steel block with over a 150 man hours invested. It managed a warm up and cam break in. It made 4 laps at 6000 max rpm and blew up. I know it's a part of rodding but I feel I have to fully understand what happened in order to let it go. Find a closure if you will. What do you think?
Attached Thumbnails
Click image for larger version

Name:	Piston top shattered.JPG
Views:	449
Size:	277.8 KB
ID:	4928   Click image for larger version

Name:	Piston bottom of 6.JPG
Views:	409
Size:	183.5 KB
ID:	4929   Click image for larger version

Name:	Pieces.JPG
Views:	437
Size:	234.5 KB
ID:	4930  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-10-2005, 01:40 PM
engineczar's Avatar
Hotrodders.com Moderator
 
Last photo:
Join Date: Sep 2002
Location: In Flowbench nirvana
Age: 52
Posts: 1,666
Wiki Edits: 0

Thanks: 6
Thanked 54 Times in 50 Posts
looks like the wrist pin seized up, did this motor run a vacuum pump? Look in the oil passage from the oil ring to the wrist pin to see if the holes connect.
__________________
BSE Racing Engines
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-10-2005, 01:41 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,088
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
A few more.

It appears to be a rod failure. They were new GM pink rods shot peened and resized. Whole assembly was balanced. Maybe the pin pulled from the piston first.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-10-2005, 01:41 PM
347mustang's Avatar
Member
 
Last photo:
Join Date: Apr 2005
Location: oklahoma
Posts: 389
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
i feel for you...mine did the same...347 motor..all eagle parts...the man that built it forgot to install the cam reatiner plate on the front..the cam walked its self to death..lol..didt hurt the crank or rods -pistons..just had to get new gaskets ..bearing and cam..lifters..the motor had less than 2 hrs running time on it ..bad thing is he closed up his shop and moved out of town..gee i wonder why..
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-10-2005, 01:48 PM
Hotrodders.com Moderator
 

Last journal entry: PICTURE TEST
Last photo:
Join Date: Jan 2004
Location: york pa
Age: 52
Posts: 2,795
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
wow

Dude what are you doing with cast pistons in a engine with 150 man hours in???? Or is it a rules deal?????

One thing i seen that bothers me is the rod bolts.... Did you take them out or was that the way you found them in the pan?????

Any chance of getting some skirt pictures of the good pistons????


Keith
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-10-2005, 02:00 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,658
Wiki Edits: 0

Thanks: 15
Thanked 60 Times in 57 Posts
Dr. Johnson I already told ya to leave those Mojo hand voodoo charms alone! lol just kiddin ya.
Just from appearence it looks as if the pin wasn`t getting lube, the score marks only on one side indicate that, although I`m not saying I`m right here, just making a observance, if that was what happened the heat centralized and the piston came apart. Sorry this happened, just make sure ya get your mojo workin before the next one.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-10-2005, 02:09 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,088
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
No vacuum pump. Wet sump only

I didn't think about the wrist pin sieze. I know this engine ran for about a year with these pistons in a different car. I was given the rotating assembly and I had my local engine guy check things for problems. He gave it a go and I never looked at em twice. Piston to wall was set a .004 except for cylinder one was .005.

Rules dictate cast piston and flat top four valve piston. The only way to make power like this is compression and close tolerances. 150 hours was for wet sump oil control. Pan modifications and a cylinder wall finish. Rod bolts for 5 and 6 were found. 5, both broken in half and were found not in the pan but caught between the crank and cam on number 2. ONe of those bolts stilll have a nut on em. Here's a pic of the rod cap of 5. The bolts for 6 were bent about 20 degree's but not broken. They were laying in the pan gates.


The bearings as well as the crank are black from heat. I wondered if a bearing failed and the piston hit the head casing it to shatter. I'll get pics of the pistons tonight
Attached Thumbnails
Click image for larger version

Name:	Beat up rod cap.JPG
Views:	286
Size:	179.6 KB
ID:	4931   Click image for larger version

Name:	#5 top.jpg
Views:	273
Size:	295.8 KB
ID:	4932   Click image for larger version

Name:	Bearings.JPG
Views:	254
Size:	202.0 KB
ID:	4933  
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-10-2005, 02:36 PM
killerformula's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Carburetor
Last journal entry: Clean up
Last photo:
Join Date: Oct 2003
Location: Northeast
Age: 34
Posts: 3,485
Wiki Edits: 3

Thanks: 13
Thanked 27 Times in 18 Posts
looks to me like you lost the bearing and perhaps the extra throw send the slug wild. Most of your stress is at the crank if you're destroying bearings. Even if you lost the wrist pin, it should affect the bearing/cap/ and rod bolts that much.

K
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-10-2005, 02:54 PM
johnsongrass1's Avatar
Race it, Don't rice it!
 
Last photo:
Join Date: Jul 2002
Location: Columbia, Mo
Age: 38
Posts: 4,088
Wiki Edits: 0

Thanks: 0
Thanked 10 Times in 10 Posts
There was severe wall damage done. The cylinder had been beat on by the loose rod attached to the crank cracked the wall about 1/8 wide extending from 1/2 from the top to the bottom. The bottom of the cyinder was beaten by debris as well. These indicate to me the rod failed above the bearing. I wish I knew which went first. The head doesn't show any signs of the piston hitting the head other than 4 bent valves. The pushrod wern't bent nor was the cam broken. Lifters appeared okay.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-10-2005, 03:06 PM
59vette's Avatar
Member
 
Last photo:
Join Date: Oct 2003
Location: UK
Posts: 78
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Without knowing all the details, I'd say that a con rod bolt gave up first.

If a piston fails, what kind if forced will pull the rod bearing cap from the rod itself.

In our large bore 4-stoke engines (6-13" bore), we sometimes see some ugly failures.

We can destroy a piston, cylinder liner, cylinder head, but the rod usually only opens if the rod bolt fails....
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 05-10-2005, 04:00 PM
spinn's Avatar
He got me, like he got you
 

Last journal entry: This makes a huge difference
Last photo:
Join Date: Oct 2004
Location: Midnight
Posts: 2,546
Wiki Edits: 0

Thanks: 14
Thanked 88 Times in 85 Posts
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 05-10-2005, 04:47 PM
oldschoolrods's Avatar
Member
 

Last journal entry: Engine Compartment
Last photo:
Join Date: Dec 2003
Location: Lancaster, Pennsylvania
Age: 28
Posts: 806
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
My 2 cents is that the rod bolt broke which caused all the major cylinder wall damage and then all that banging around took out the bearings. Nasty one.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 05-10-2005, 05:27 PM
Bumpstick's Avatar
Hammer and a torch
 
Last photo:
Join Date: May 2003
Location: Southeast TX
Age: 54
Posts: 1,258
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Have a feeling the pin pulled out of the first piston which started the chain reaction...? The cast pistons are very noted around here in my area for doing just that (dirt track heaven around here)... After it let go it basicly ate itself from the severe imbalanced condition and high RPM... Very sad to see it happen...
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 05-10-2005, 06:45 PM
docvette's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Rebuild an alternator Last photo:
Join Date: Mar 2004
Location: Lafayette, california
Age: 62
Posts: 7,362
Wiki Edits: 12

Thanks: 0
Thanked 6 Times in 3 Posts
Wrist pin

Doc here,

How about this scenario, The wrist pin seized, then broke apart at the piston skirt just before a fire stroke sending the slug down on the rod while it was traveling up...Thus breaking the piston up and spreading the big end of the up coming rod , breaking the bolts and the allowing the bearing to cut loose..the rest of the damage being secondary to the first failure...as it wound down..

Just a thought..the pics are a bit hard to tell..really BIG..and close up.

Doc
__________________
Aftermarket Solutions
Electronic & Electrical
Innovations
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 05-10-2005, 07:53 PM
Member
 
Last photo:
Join Date: Nov 2004
Location: Indiana
Age: 60
Posts: 393
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I agree with 59vette connecting rod bolt broke and took everything else out.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
bang boom oldsmo Transmission - Rearend 3 03-23-2005 07:27 PM
Burnout makes the rear end go boom! BanditT/A Transmission - Rearend 11 10-06-2004 07:16 PM
One too many RPMs, engine go BOOM! Jmark Engine 22 04-02-2004 03:15 PM
BOOM! Just had a big eathtquake. willys36@aol.com Hotrodders' Lounge 15 12-23-2003 08:28 AM
Which home stereo speakers? CET Hotrodders' Lounge 13 10-06-2003 12:34 AM


All times are GMT -6. The time now is 01:26 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.