Antique Tractors
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Old Iron and Tractor Community > Antique Steel Wheel Tractors - Old Iron Lugs and Cleats
Forgot Password? Join Us!

Notices

Antique Steel Wheel Tractors - Old Iron Lugs and Cleats Photos and information about antique steel wheeled farm tractors. This is where to find the heaviest of Old Iron tractors.

Antique Steel Wheel Tractors - Old Iron Lugs and Cleats

18-36 Hart Parr ConRod Cracks


this thread has 25 replies and has been viewed 1751 times

Reply
 
Thread Tools Display Modes
  #1  
Old 08-15-2019, 09:42:05 PM
steelwheelrat steelwheelrat is offline
Registered
 
Join Date: Jun 2010
Location: Jasper Mo
Posts: 96
Thanks: 8
Thanked 167 Times in 46 Posts
Default 18-36 Hart Parr ConRod Cracks

Putting an engine together and stumbled upon something rather concerning. Both of the connecting rods I have what appear to be identical cracks. Has anyone run into this???

They are as close to identical as it gets. My first inclination is to assume they are a defect something akin hot tears in castings but they are deeper in the heavier mass than you would normally see in casting hot tears. Witness Mark's say the rods came out of different forging dies. Any insight?
Attached Thumbnails
Click image for larger version

Name:	20190815_203326.jpg
Views:	278
Size:	169.0 KB
ID:	341541   Click image for larger version

Name:	20190815_201904.jpg
Views:	275
Size:	119.2 KB
ID:	341542   Click image for larger version

Name:	20190815_201855.jpg
Views:	239
Size:	171.6 KB
ID:	341543   Click image for larger version

Name:	20190815_201312.jpg
Views:	233
Size:	94.7 KB
ID:	341544  
Reply With Quote
The Following 3 Users Say Thank You to steelwheelrat For This Post:
Sponsored Links
  #2  
Old 08-15-2019, 11:01:18 PM
Greg Mosley Greg Mosley is online now
Registered
 
Join Date: Jan 2005
Location: Nebraska
Posts: 383
Thanks: 399
Thanked 357 Times in 167 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Greetings Steelwheelrat, A few ideas. (1) Metal fatigue from age,
(2) over tightening pinch bolt to compensate for pin eyelet bushing to wrist pin wear. (3) pin eyelet slapping from being too loose (4) pin eyelet tolerance to tight at one time. Glad you found it during inspection. Enuf Said.
Reply With Quote
The Following User Says Thank You to Greg Mosley For This Post:
  #3  
Old 08-15-2019, 11:37:21 PM
Jeff Blaney Jeff Blaney is offline
Subscriber
 
Join Date: Jan 2006
Location: Beeton, Ontario, Canada
Posts: 829
Thanks: 2,081
Thanked 1,319 Times in 430 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

It is difficult to see in the pictures, do the cracks extend all the way to the flat where the head of the bolt seats?
Reply With Quote
The Following User Says Thank You to Jeff Blaney For This Post:
  #4  
Old 08-15-2019, 11:42:31 PM
casertractor casertractor is offline
Subscriber
 
Join Date: Feb 2006
Location: Milton, Ontario, Canada
Posts: 5,350
Thanks: 25,330
Thanked 5,968 Times in 2,451 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Looks like they have been cut?
Reply With Quote
  #5  
Old 08-16-2019, 07:32:15 AM
Wayne Riedlinger Wayne Riedlinger is offline
Subscriber
 
Join Date: Mar 2006
Location: Stonyplain, Alberta, Canada
Posts: 1,057
Thanks: 1,195
Thanked 1,403 Times in 390 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Sure looks like somone cut them to me also. But Why?.
Reply With Quote
The Following User Says Thank You to Wayne Riedlinger For This Post:
  #6  
Old 08-16-2019, 08:32:17 AM
Stuart Landry Stuart Landry is offline
Subscriber
 
Join Date: Dec 2006
Location: Leongatha South, Victoria, Australia
Posts: 120
Thanks: 522
Thanked 492 Times in 77 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Hi, I think this cracking is caused by side to side slapping of conrod, ( can see heavy wear on side face in pictures )
Which in tun , could be caused by end float of crankshaft ,
Badly worn or out of Parallel crank pins ,
cylinder out of square with crankshaft,
Hope this helps ,
Reply With Quote
The Following User Says Thank You to Stuart Landry For This Post:
  #7  
Old 08-16-2019, 10:27:17 AM
Bubbles Bubbles is offline
Registered
 
Join Date: Jul 2009
Location: Oilpull Central
Posts: 378
Thanks: 96
Thanked 524 Times in 231 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Those cuts are supposed to be there, it allows the screw to slightly compress the material. The poster is talking about the hairline cracks in between the paint marks.
Reply With Quote
The Following 2 Users Say Thank You to Bubbles For This Post:
  #8  
Old 08-16-2019, 11:48:14 AM
steelwheelrat steelwheelrat is offline
Registered
 
Join Date: Jun 2010
Location: Jasper Mo
Posts: 96
Thanks: 8
Thanked 167 Times in 46 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Defects as consistent as these cracks generally indicate that there is an issue with the design, metallurgy or manufacturing process. I was curious if anyone else had seen this particular crack in 18-36 Hart Parr rods. With the wealth of knowledge and experience that the Stak community has and the popularity and survival rate of this particular model, I was hoping that if this was a benign issue, someone would have seen it before. I threw the rods on a mag machine this morning and the visual indication is confirmed as a crack in identical locations and lengths on both units.

In modern engines, defects like this are common. Some are benign and others are catastrophic if not repaired. No one ever wants to see a rod turn loose and an antique engine go boom so caution and research are mandatory. Engine booms can be entertaining at the drag strip or at the hotrod tractor pulls but obviously, these parts are slightly more difficult to obtain than say, a 5.9L Cummins or a 9.0L Cursor Iveco like the one in the picture. The last thing I want this to do is end up looking like the one in the picture.

Thanks for the input everyone, I think I repair the cracks before I use them.
Attached Thumbnails
Click image for larger version

Name:	20180702_140122.jpg
Views:	217
Size:	209.6 KB
ID:	341554   Click image for larger version

Name:	Inked20190816_095740_LI.jpg
Views:	174
Size:	80.6 KB
ID:	341559   Click image for larger version

Name:	Inked20190816_095745_LI.jpg
Views:	173
Size:	74.2 KB
ID:	341560  
Reply With Quote
The Following 4 Users Say Thank You to steelwheelrat For This Post:
  #9  
Old 08-16-2019, 12:52:29 PM
Jeff Blaney Jeff Blaney is offline
Subscriber
 
Join Date: Jan 2006
Location: Beeton, Ontario, Canada
Posts: 829
Thanks: 2,081
Thanked 1,319 Times in 430 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

That is interesting that the crack does not run all the way to the edge of the rod. If they weren't there from the very beginning, I would guess they are a result of tensile stress placed on the rod caused by excessive wrist pin clearance. The pistons may have been slapping back and forth in line with the rod at TDC and at the bottom of the stroke, pulling and compressing the small end of the rod?
Just a guess!
Reply With Quote
The Following User Says Thank You to Jeff Blaney For This Post:
  #10  
Old 08-16-2019, 02:03:23 PM
Russ Hamm's Avatar
Russ Hamm Russ Hamm is offline
Subscriber
 
Join Date: Dec 2005
Location: Canton, Kansas, USA
Posts: 1,760
Thanks: 1,285
Thanked 2,986 Times in 979 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by steelwheelrat View Post
Defects as consistent as these cracks generally indicate that there is an issue with the design, metallurgy or manufacturing process. I was curious if anyone else had seen this particular crack in 18-36 Hart Parr rods. With the wealth of knowledge and experience that the Stak community has and the popularity and survival rate of this particular model, I was hoping that if this was a benign issue, someone would have seen it before. I threw the rods on a mag machine this morning and the visual indication is confirmed as a crack in identical locations and lengths on both units.

In modern engines, defects like this are common. Some are benign and others are catastrophic if not repaired. No one ever wants to see a rod turn loose and an antique engine go boom so caution and research are mandatory. Engine booms can be entertaining at the drag strip or at the hotrod tractor pulls but obviously, these parts are slightly more difficult to obtain than say, a 5.9L Cummins or a 9.0L Cursor Iveco like the one in the picture. The last thing I want this to do is end up looking like the one in the picture.

Thanks for the input everyone, I think I repair the cracks before I use them.
Reminds me of this famous image from awhile back, haste prevented proper torque on the main bearing caps and the crank was pushed out.
Attached Thumbnails
Click image for larger version

Name:	magic.jpg
Views:	209
Size:	42.3 KB
ID:	341567  
Reply With Quote
The Following 3 Users Say Thank You to Russ Hamm For This Post:
  #11  
Old 08-16-2019, 07:49:28 PM
Craig A's Avatar
Craig A Craig A is offline
Moderator
 
Join Date: Nov 2004
Location: Wisconsin, USA
Posts: 15,475
Thanks: 16,772
Thanked 20,661 Times in 5,982 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by steelwheelrat View Post
Defects as consistent as these cracks generally indicate that there is an issue with the design, metallurgy or manufacturing process. I was curious if anyone else had seen this particular crack in 18-36 Hart Parr rods.
I forgot how many Hart Parr engines I did but I never saw anything like that.
Reply With Quote
The Following 2 Users Say Thank You to Craig A For This Post:
  #12  
Old 08-18-2019, 06:32:37 PM
Jon Nessel's Avatar
Jon Nessel Jon Nessel is offline
Subscriber
 
Join Date: Sep 2007
Location: Chilliwack B.C. Canada
Posts: 648
Thanks: 914
Thanked 1,092 Times in 317 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by Russ Hamm View Post
haste prevented proper torque on the main bearing caps and the crank was pushed out.
...with a gentle nudge from the aluminum thingy poking out of the hood. Must be a Chevy... or was🤪
Reply With Quote
  #13  
Old 08-19-2019, 09:06:18 AM
I like oldstuff I like oldstuff is offline
Subscriber
 
Join Date: Jan 2012
Location: Milwaukee, Wisconsin, USA
Posts: 6,246
Thanks: 1,596
Thanked 7,399 Times in 2,716 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

354 chrysler
Reply With Quote
The Following User Says Thank You to I like oldstuff For This Post:
  #14  
Old 08-19-2019, 10:03:20 AM
Russ Hamm's Avatar
Russ Hamm Russ Hamm is offline
Subscriber
 
Join Date: Dec 2005
Location: Canton, Kansas, USA
Posts: 1,760
Thanks: 1,285
Thanked 2,986 Times in 979 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by I like oldstuff View Post
354 chrysler
I was thinking 392, and from what I can remember reading about the history of this car, that block was saved, although never in that car again.
Reply With Quote
  #15  
Old 08-19-2019, 01:20:09 PM
G Willikers G Willikers is offline
Sponsor
 
Join Date: Mar 2006
Location: Canada
Posts: 12,877
Thanks: 12,390
Thanked 29,591 Times in 7,463 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by Greg Mosley View Post
(2) over tightening pinch bolt to compensate for pin eyelet bushing to wrist pin wear. .
I'll go out on a limb and agree with Mr. Mosley as this for a cause.
We'll never know what happened in the past. The over tightening could have been combined with an over-speed event also?
Good that the cracks were discovered now, and anything more serious prevented.
Reply With Quote
The Following 2 Users Say Thank You to G Willikers For This Post:
  #16  
Old 08-19-2019, 11:57:18 PM
Duey C Duey C is offline
Subscriber
 
Join Date: Jan 2014
Location: Central, Minnesota, USA
Posts: 548
Thanks: 1,083
Thanked 719 Times in 358 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

How many other running/working Hart-Parr rods have these very same cracks is my noodling? Very interesting thread rat!
Reply With Quote
  #17  
Old 08-20-2019, 12:21:20 AM
Jon Nessel's Avatar
Jon Nessel Jon Nessel is offline
Subscriber
 
Join Date: Sep 2007
Location: Chilliwack B.C. Canada
Posts: 648
Thanks: 914
Thanked 1,092 Times in 317 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by G Willikers View Post
I'll go out on a limb and agree with Mr. Mosley as this for a cause.
We'll never know what happened in the past. The over tightening could have been combined with an over-speed event also?
Good that the cracks were discovered now, and anything more serious prevented.
I know I'll be taking a real good look at mine 'for it goes back together. Hope JB didn't sell me a lemon!
Reply With Quote
  #18  
Old 08-20-2019, 12:49:45 AM
David Hoover David Hoover is offline
Subscriber
 
Join Date: Dec 2008
Location: Edmonton, Alberta, Canada
Posts: 1,642
Thanks: 2,346
Thanked 4,174 Times in 1,279 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Quote:
Originally Posted by Duey C View Post
How many other running/working Hart-Parr rods have these very same cracks is my noodling? Very interesting thread rat!
I don’t think it’s a Hart Parr flaw, I’ve worked on a few and never saw cracks like that. I haven’t seen any grenaded Hart Parr’s either. I have a pair of 18-36 Model G rods on my bench now and no cracks on them. I think that one had a rough experience and luckily was found before it came apart.
Reply With Quote
The Following User Says Thank You to David Hoover For This Post:
  #19  
Old 08-20-2019, 10:16:26 AM
Jeff Blaney Jeff Blaney is offline
Subscriber
 
Join Date: Jan 2006
Location: Beeton, Ontario, Canada
Posts: 829
Thanks: 2,081
Thanked 1,319 Times in 430 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

David, could you do me a favour?
I would like to know the journal diameter and journal width on those Hart Parr connecting rods. Also, what is the center to center distance from throw to wrist pin? I am considering re-purposing some connecting rods for another project.
Reply With Quote
The Following 2 Users Say Thank You to Jeff Blaney For This Post:
  #20  
Old 08-20-2019, 10:40:25 AM
David Hoover David Hoover is offline
Subscriber
 
Join Date: Dec 2008
Location: Edmonton, Alberta, Canada
Posts: 1,642
Thanks: 2,346
Thanked 4,174 Times in 1,279 Posts
Default Re: 18-36 Hart Parr ConRod Cracks

Sure, I’ll check tonight.
Reply With Quote
The Following User Says Thank You to David Hoover For This Post:
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
Hart Parr 15-30A value? smcmanus Antique Steel Wheel Tractors - Old Iron Lugs and Cleats 63 10-04-2016 09:49:43 PM
Hart Parr 40-80 rob hart parr Antique Steel Wheel Tractors - Old Iron Lugs and Cleats 43 09-24-2015 10:39:43 PM
Hart Parr 15-30A Pat Bayer Antique Steel Wheel Tractors - Old Iron Lugs and Cleats 19 05-31-2015 11:16:58 PM
Hart Parr taylorjisa Antique Steel Wheel Tractors - Old Iron Lugs and Cleats 1 03-29-2014 05:35:11 PM
28-50 Hart Parr peterson1 Antique Steel Wheel Tractors - Old Iron Lugs and Cleats 3 09-01-2010 07:53:07 AM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 03:17:20 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277