Help Please!! Cracked oil galley

Replace it..

Welding cast is tricky and it may keep on cracking any way.

It is the oil cooler correct?

If the block, Well maybe time to get a bare block and use what you have.

 

It’s got a bit to do with why they re sculptured the C model blocks when they removed the Cam tunnel as it was in the 3406E blocks. Two reasons for this and one was they didn’t need the cam tunnel anymore and to also add some integrity into the block as it was flexing too much and Cracking.
Cat have also gone away from the Gas threads used on the block at the oil gallery drillings and gone to O- ring plugs with parallel threads. Trouble with the old Gas thread was it’s a taper and it wants to open the hole the more you tighten. Heavy handed fitters! The early C blocks also had Gas threads!
Traditionally we never weld blocks anymore and we stitch them. However I would also machine out the Gas thread and machine in an O ring with parallel thread to stop it opening up again.

 

The 5EK blocks did this when you started building big power. I would assume that the blocks are very similar to each other. The 1LW block has much more material in it and will take the extra power without breaking. I have a friend that went through two 5EK block before going to a 1LW block, since that time we've added some power to it and the block has held up without any issues. He cracked his 5EK blocks in the same place you are discribing

My suggeastion is.........get a 1LW block and swap your parts into it.

 

The early E model blocks are weak is all and how many miles and full load cycles has it seen.......I don't know of a good way to fix this

 

JB Weld?

Trying to fix it in a day, Not being rude but I believe that is going to be impossiable..
Wish you the best.

Main thing is worrying about the cracks growing on you. even after welding or stitching.

Kinda curious about that as well..
Any way good luck with fixing the problem.