Repairing an external crack on an iron engine block
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Repairing an external crack on an iron engine block
Posted: August 12 2007 08:28 AM
 
John Cooper (aka aroldfut) [ View ] [ aroldfut@aol.com ] [ Car Ads ] [ Blogs ]
Russellville, Arkansas
(479) 967-0862
 
Not hardly a 'streetrod' issue, but relevant to engine repair. My neighbor came to me and asked if I knew of a method to repair a crack in his old Ford 801 tractor iron engine block. The crack is hairline but about 5" long. It's on the horizontal side of the block and is about one-inch from the spin-on oil filter boss. He's tried JB-Weld epoxy but the oil pressure behind the crack and/or heat causes it to fail. Anybody know of a welding technique or a new epoxy that works?
 
 
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Posted by Crazyhorse Rod Shop  -  08/12/2007 08:43 AM
you have to preheat it and use a high nickel rod. oldred may chime in here as he worked with mining equipment for years. it's pretty tuff but can be done.
dont poke the porchdog........he bites [ View ] [ Email ] [ Blogs ] [ Car Ads ] BLUFF DALE, Texas Charter Member since March 2003
 
Posted by Jaybird  -  08/12/2007 09:28 AM
What Shine said. Also, look very carefully and locate each end of the crack. Dill as mall hole at or just beyond the crack end. This will stop the crack from growing as you heat it. If you don't you'll just keep chacing it down the side of the block.
Jaybird [ View ] [ Email ] [ Blogs ] [ Car Ads ] Cincinnati, Ohio Charter Member since December 2003
 
Posted by Streetrodder007  -  08/12/2007 10:25 AM
Shine is dead on right. I have had a few Hemi blocks repaired very expensive but worth it for non replacable items. Check out the pics I loaded, Its a 392 Hemi, block was cracked from #3 to #5 cylinder by freeze plug, roughly 6" long, It cost me $800 to have it baked to 600 degrees and ground out and fillet welded with Hi-Nickel rod then they grind the weld smooth and restamp a sand like casting in the side while its hot, so it looks original. In the pic you will see a round weld and drill, thats the beginning, hard to see, but if you look closely, it their.

If it was a cheap block like a sbc- it would go in the garbage, not worth the money. But the shop I use is about 1 hour from me, and the guy does mostly farm equipment that is cast iron and you can no longer buy some of the items, and rare hotrod blocks, etc.
Streetrodder007 [ View ] [ Email ] [ Blogs ] [ Car Ads ] Port Huron, Michigan Charter Member since April 2006
 
Posted by Streetrodder007  -  08/12/2007 10:29 AM
I have lots of other pics of repaired engine blocks if you need to see them. Anybody can weld a rod on a block, but a real good shop will almost make it impossible to see the repair.

My advice, dont just use any old welding shop, find some one who specializes in it. I thought about trying it myself, but a small box of 3/16" high-nickel is about $125 for just the rod.
Streetrodder007 [ View ] [ Email ] [ Blogs ] [ Car Ads ] Port Huron, Michigan Charter Member since April 2006
 
Posted by Alf  -  08/12/2007 11:28 AM
I have had good luck using a type of rod called "super missle weld". I used this to repair a finger brake that some of my friends broke. It is probably just a high nickel rod with a fancy name, but it works and it is easy to use.
Lanny Netz [ View ] [ Email ] [ Blogs ] [ Car Ads ] Grass Valley, California
 
Posted by oldred  -  08/12/2007 12:16 PM
Hi, New here and I like the looks of this place! Any kind of crack in an iron casting can be tricky to repair and idealy should be done by a specilized shop but I know that is not always practical. It is very important to get it right on the first try because any failed repair will only add to the damage and in the case of an engine block doing it wrong the first time could be a disaster. Trying to weld the block without tearing down the engine and thourghly cleaning the block inside and out is almost always a recipe for disaster so unfortuantley this can get quite involved. After cleaning the block needs to be heated evenly in an oven where the heating rate can be controled and then after the repair it needs to be cooled at a controled rate. This is a very breif description of how a shop would do it so you can see how involved it can get. If you decide to do this yourself without doing the engine tear-down you first need to drain the block completely and then try to warm it up enough to make sure it gets thoughly dry inside, don't try to heat it too hot because uneven heat is worse than not heating at all so just heat it enough to dry out the inside. Drill those stop holes already mentioned at the ends of the crack and then bevel it out almost to the bottom with a grinder. Use a 3/32" Ni 55 Nickel rod for cast iron (don't use the Ni 99) and weld in very short stitches about a 1/2" long stopping to peen each weld by tapping on it with the pointed end of a chipping hammer until it cools then proceed to the next stitch until you finish, don't allow the block to become too hot. This is known as the cold weld process for cast iron and is the prefered way when oven heating can not be done because as I said uneven preheating can be worse than no preheating. Don't be tempted to use the "99" rod thinking it must be better because of the much higher price since it's advantage is that it is machinable after welding which is of no concern here and the "55" is less prone to cracking also the peening step is very important to releive stress between passes and should not be left out. There are dozens of myths out there concerning welding cast iron and if you ask twenty people you are likely to get twenty conflicting opinions so it will be up to you to decide how to do this but the method I have described has worked well for me. By far the best and most sure way of doing this would be to take the block to a reputable shop with block repair experiance to have this done.
oldred [ View ] [ Email ] [ Blogs ] [ Car Ads ] lafollette, Tennessee
 
Posted by Streetrodder007  -  08/12/2007 01:43 PM
Here is a few more pics of a 1965 & a 1968 426 Hemi block that were both just repaired about 2 months ago. There was a hole big enough to put your hand into, right where the Hemi number stamp is, you can barely make out the outline of the repair. $1100 to fix this block entirely and obviously it was magged about 10 times for any other problems.
Streetrodder007 [ View ] [ Email ] [ Blogs ] [ Car Ads ] Port Huron, Michigan Charter Member since April 2006
 
Posted by Crazyhorse Rod Shop  -  08/12/2007 04:48 PM
thanks red ! glad you stopped by. not as many boneheads here as the other one ( except me )
dont poke the porchdog........he bites [ View ] [ Email ] [ Blogs ] [ Car Ads ] BLUFF DALE, Texas Charter Member since March 2003
 
Posted by oldred  -  08/12/2007 05:04 PM
Yeah it looks like there are some great guys here I think I really like this place.
oldred [ View ] [ Email ] [ Blogs ] [ Car Ads ] lafollette, Tennessee
 
Posted by aroldfut  -  08/12/2007 05:04 PM
Thanks for all the pictures and replies. I'll hunt-up some nickel rod Monday. Unfortunately out here in the country the only pre-heating I'll be able to do is with a torch... I doubt the wife will let me put a tractor block in our kitchen oven.


This site continues to be a 'brain-trust' of information and amaze me. It's more than worth the Charter Membership price to keep it active (a little plug for Eric & Co.) Thanks again! ...John
aroldfut [ View ] [ Email ] [ Blogs ] [ Car Ads ] Russellville, Arkansas Charter Member since August 2003
 
Posted by jim.a  -  09/28/2007 06:02 PM
new here so bare with me I tend to get long winded.....worked for ingersol rand years ago serviceing large recip air compressors...water jackets and cylinder wall would crack all the time..for fear of hitting an air pocket while welding [instead of trying to fix a crack you end up with a hole the size of a coffee cup ] we would bring in a company out of buffalo ny and they would stitch up the crack...stop drill all cracks..every inch drill another hole they would tap these holes install allen head set screws in them .......useing a pneaumatic hammer they would pound in there secret alloys into the crack when done they remove the set screws and fill the holes with more alloy..always worked..process is called metal stiching
jim.a [ View ] [ Email ] [ Blogs ] [ Car Ads ] tyngsboro, Massachusetts
 
Posted by 35window  -  09/28/2007 06:06 PM
Hey oldred! I'm one of the other boneheads! Glad to see you here!
35window [ View ] [ Email ] [ Blogs ] [ Car Ads ] springville, Utah
 
Posted by meangene  -  09/28/2007 07:01 PM
hey 35 window,did you find a grille for your car i came across one a guy has didn't get a chance to check it out it was 10ft off the floor onthe wall,but if interested i'll look
even a blind hog finds a acorn [ View ] [ Email ] [ Blogs ] [ Car Ads ] Labadie, Missouri
 
Posted by oldred  -  09/29/2007 08:07 PM
Hi 35, I have not posted much here but this sure looks like a nice place to hang out.
oldred [ View ] [ Email ] [ Blogs ] [ Car Ads ] lafollette, Tennessee
 
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