Interesting crack repair video.....

sidevalve8ba

Well-known member
I saw this crack repair video on the HAMB. Had to bring it over to my friends here on The Barn.

https://youtu.be/evML7xAo0bM
 
That is a great video. Provides good incite as to why automotive machining is expensive, time consuming, and requires a great deal of skill with top notch machines and machinists with problem solving ability. Wonder what that particular amount of work cost?
Thanks for posting.
 
I watched the video - the only part that I disagree with is that he didn't pin the transfer area. It would have only needed about 3 additional pins, but it might also prevent the crack from seeping water later on. There is water under the transfer area as it cools the valve pocket area.
 
This is an amazing video and it is dealing with exactly what I am working on now. Couldn't have come at a better time in my rebuild dealing with cracks in blocks and how to deal with them. Thanks Ronnie for posting the link to it.
 
I really enjoyed the video too. Suddenly crack repair is less mysterious and seems practical for us 'stay at home mechanics.'
 
It is important to note that you must use the special taps that come with the kits. Also, you can order the "pins" in quite a few different sizes.

Sometimes you'll get a slight bit of air weeping around a pin (as shown later in his video). While one can continue to solve every last little bit - it isn't always necessary. I always use a can of Moroso Ceramic Seal when a repaired engine like this is first ran - as another level of insurance.
 
This video came at a good time for me and I watched it with interest. I fixed 2 similar cracks in my 8BA block a couple of years ago. (https://www.fordbarn.com/forum/showthread.php?t=258253&highlight=Eagle43). I got the truck finished last fall and the motor ran fine on two outings. Earlier this summer it suddenly lost power and ran rough. After trying all sorts of solutions and narrowing it down to having no compression in cylinder #2, I finally pulled the head and discovered that the hardened valve seat I had installed had come loose and was rattling around. The fixed cracks seem to be holding up fine and are almost invisible. I bought a new valve and valve seat and am waiting for the Permatex 64000 high temperature sleeve retainer I ordered online. I think this is the stuff they were using in the video. Loctite 640 should be similar.
 
My Permatex Sleeve Retainer came today and I installed the hardened valve seat with this stuff. Tomorrow I plan to grind and lap the valve and put everything back together. Hopefully this seat will stay in place. It seemed to go in there pretty snug.

The first picture shows the installed seat. I've already beveled the inside a bit using my wood lathe. The second picture shows the inside of cylinder #3 which looks good. The third picture shows cylinder #2, the problem one. This one had the deepest crack in the cylinder wall with some distortion and gave me the most trouble cleaning up and trueing the cylinder wall without putting in a sleeve which I'm not capable of doing. The yellow spot is where I ground out a bit too much. I know it's not perfect but I hope things hold together and I get enough compression in this cylinder. Hope to drive the truck this weekend.
 

Attachments

  • IMG_20240827_192045_0.jpg
    IMG_20240827_192045_0.jpg
    85.1 KB · Views: 36
  • IMG_20240818_140004_3.jpg
    IMG_20240818_140004_3.jpg
    49.8 KB · Views: 36
  • IMG_20240818_140139_3.jpg
    IMG_20240818_140139_3.jpg
    62.4 KB · Views: 40
  • 717JEYIrauL._AC_SL1500_.jpg
    717JEYIrauL._AC_SL1500_.jpg
    39.9 KB · Views: 26
Fascinating video. Why is the iron so thin where the crack occurred between the valve pocket and the water jacket? Are they all like that? Is it due to casting variations?
 
Fascinating video. Why is the iron so thin where the crack occurred between the valve pocket and the water jacket? Are they all like that? Is it due to casting variations?


They're all pretty thin there. Just not a lot of room for both the port and water to cool it.
 
They cool better if the casting is thin. The model B engines may have been too thin around the valves. They crack a lot easier than the model A engines do. The V8s have always been problematic with cracking if the engine is overheated too much. It pays to keep the cooling system in top condition.
 
My Permatex Sleeve Retainer came today and I installed the hardened valve seat with this stuff. Tomorrow I plan to grind and lap the valve and put everything back together. Hopefully this seat will stay in place. It seemed to go in there pretty snug.

While I do hope that your valveseat stays where it belongs I would not bet on it.
The seats are always a shrink fit, so it would not go in the recess without heat and / or force. On an Aluminium Engine it would be 1/250 of the diameter of the seat for correct overlap, on an Iron flathead I use 1/300 as the seat expansion and engine expansion rate are almost the same. That means the seat is always a bit bigger than the recess and will be unable to move.
 
My Permatex Sleeve Retainer came today and I installed the hardened valve seat with this stuff. Tomorrow I plan to grind and lap the valve and put everything back together. Hopefully this seat will stay in place. It seemed to go in there pretty snug.

While I do hope that your valveseat stays where it belongs I would not bet on it.
The seats are always a shrink fit, so it would not go in the recess without heat and / or force. On an Aluminium Engine it would be 1/250 of the diameter of the seat for correct overlap, on an Iron flathead I use 1/300 as the seat expansion and engine expansion rate are almost the same. That means the seat is always a bit bigger than the recess and will be unable to move.

I had the seat in the freezer just before I hammered it into place. It took quite a bit of force to get it to seat.
 
Back
Top