Jump to content

Recommended Posts

http://s1244.photobucket.com/user/wmmccall/library/?sort=3&page=1

 

Above is a link to some (larger) pictures of some holes in my 242 block. Casting#: 53010341, Date: 3/14/1997. Salvage yard said it "tested good". All my small block chevy friends say don't worry about them and if I am worried to just JB weld them. This my first tear down and hopefully stroke it with the rebuild. The holes to me appear to be from some kind of wear, but don't look like they will affect anything.  Should I grind a little to prevent chipping or pieces flaking off.

 

Note: I did see a picture of the XJ it came from and it was salvaged due to a bad passenger side collision...or so it appeared.

 

Thanks, Wayman

post-16-0-37536200-1367885710_thumb.jpg

post-16-0-46217500-1367885711_thumb.jpg

Link to comment
Share on other sites

  • Administrators

Wayman, I took the initiative to look at your pics in the photo bucket. The chipped section between the lifter bores is not a great issue, though you should smooth out the rough edges that might slough off iron in service.

The other break concerns me. Is this a punched out block section at the timing cover area? What's on the back side of the break/hole? Is this the thin casting where the block timing cover section extends out from the block?

The real concern is loss of oil or an opening into a cooling jacket. From what you're suggesting, it sounds like this hole/break opens away from the block's cooling jackets or ports. That would be critical. You still need to contain oil in the engine, as the timing cover area has a high wash of slinging oil.

Let me know what's on the other side of the break. If there's any way to fix this hole in the casting, your main concern is to grind off any material that could slough off into the crankcase or find its way between moving parts.

I'm not a huge fan of J-B Weld, however, it will work in areas that do not have pressure or excessive heat. J-B Weld is around 3,000 psi tensile and works to around 300 degrees F, depending upon the type of J-B and cure time. This is not a lot to get excited about when you consider an iron block is typically 40-50,000 psi tensile and can get good and hot in service.

If you can, take a picture of the hole's backside, so I can get a better perspective. I TIG weld cast iron, using Weld Mold 700 and 750 filler with great results. See this link for an example of my TIG repair of cast iron: http://www.4wdmechanix.com/TIG-Welding-Technique.html.

Careful bronze or silver brazing can also work in an unstressed area cast repair, as long as there's no concern about warping or you can square the slightly distorted surface with either a milling machine or careful hand mill filing. Such repairs depend upon the size of this hole/break and the equipment available.

Moses

Link to comment
Share on other sites

Looks like the hole under the timing is just above the hole for the lifter. I watched one of the Tony Hewes stoker videos and the block that was using the 258 rods you guys were talking about  appears to have the same hole. But couldn't really get a good look.

post-16-0-62046500-1368318886_thumb.jpg

post-16-0-89801200-1368318887_thumb.jpg

Link to comment
Share on other sites

  • Administrators

Okay, Wayman, this looks a lot better!  I pored over the Hewes Performance videos to find the best image of your "hole".  At http://www.4wdmechanix.com/HD-Video-Jeep-4.6L-Inline-Six-Pistons,-Rods-and-Bearings.html, check around 4:04 minutes, with the HD mode in full-screen view...You'll see a "hole".  This is a casting design, likely to drain pooled oil from the lifter area and provide more timing chain lubrication in the process.

 

Sounds like you're doing a detailed rebuild and observed the rough casting edges at the hole. Unfortunately, casting flash is common on cast iron, mass produced engine blocks.  I always go over the block and assess what poses a threat of sloughing off fragments—the risk of a piece of casting migrating into the crankcase or between moving parts. 

 

The rationale "well it stayed put this long" doesn't work for me, and apparently, you're discriminating, too.  If in doubt, take a die-grinder with carbide burr tool and smooth out the rough edges to the point that the casting looks stable, nothing excessive, just enough to remove the threat of sloughing.  Always remove debris thoroughly, including any fine iron powder from the grinding process.  This is abrasive stuff!

 

Make sense?  Does this confirm what you're looking at?  If so, don't attempt the use of J-B Weld—if the patch doesn't set well or is affected by oil over time, J-B Weld or similar materials could slough and end up in the oil pan.  The threat here is plugging up the oil pump pickup screen, although it would take a lot of J-B Weld fragments to create a significant problem.

 

As a footnote, my remarks are not intended to detract from the value of J-B Weld...I can think of many occasions where the right J-B Weld product has been a tremendous asset: as an emergency trail aid or inexpensive way to save an expensive, damaged part—like a non-stressed motorcycle side cover with a chip or crack.

 

Trust this helps, Wayman...

 

Moses

Link to comment
Share on other sites

  • Administrators

Wayman, from what I saw, there is really no need for J-B Weld.  If you just smooth out the casting "flash" and leave a solid casting, you'll be in good shape.  Do not remove structural material. The oil transfer hole at the timing cover area of the block should simply require shaping the rough flashing edges to reduce risk of sloughing.  I saw no point in adding J-B Weld.  What's your thought there?

 

To provide some peace of mind, I found this definition of casting "flash" to help you better understand the issue:

 

http://www.abymc.com/tmoranwms/Casting_Defects.html

 

Trust this is helpful...On the issue between the two lifter bores, send me a close-up photo that details your concern there. 

 

Moses

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...