So, I wrecked my truck and decided to replace the engine due to the 53 block being cracked. Problem has been finding anything other than a 53. So, I'm back to the idea of repairing the block. I will not be hotrodding this truck. In fact, I've only put about 3k miles on it since buying it in January 2011 (tow vehicle only). I also know that I should replace the block. I'm looking for no kidding factual information from experienced folks who have either succeeded or failed at repairs, whether it be by welding or Lock N Stitch. Thanks

From what Ive found you lock and stitch it then flux it.

I too was in your shoes and I will tell you as a welder by trade you need to find another eng. For what it will cost you to repair it right will far exceed the cost of a rebuild. The lock and stich (I dont care what they say) will not work. You would be better off to weld with brass then that. If you do weld it you will need to use block heater everytime you start it in cold weather due to expansion contraction, it will crack again in time.Like I said the cost will be high. I just found another eng out of a wrecked truck, gave 2k for it and back on the road again.It is tempting to buy one of those low mileage eng. but stay away

I am no expert on a 53 block, but i have not seen any method that any body will gaurantee the fix will work. I would have to agree with Jl on trying to find a replacement. Just my .

  DezrtRat said:

So, I wrecked my truck and decided to replace the engine due to the 53 block being cracked. Problem has been finding anything other than a 53. So, I'm back to the idea of repairing the block. I will not be hotrodding this truck. In fact, I've only put about 3k miles on it since buying it in January 2011 (tow vehicle only). I also know that I should replace the block. I'm looking for no kidding factual information from experienced folks who have either succeeded or failed at repairs, whether it be by welding or Lock N Stitch. Thanks

$1500 for New Block,$1000 for Rebuild kit(rings,bearings,gaskets,seals), from Frieghtliner $400 for head work,use all you existing hard parts,pay for labor or do it yourself.

if it were me, i would get a new block and rebuild it myself. Replace anything that needs it and you will be good to go. A little effort will save you some major bank on this!

Thanks for the fedback. I'm so surprised how hard it is to find a used motor that's not a 53 block. I can buy used 53's all day for around $1500 but then I would always be wondering. I'm doing this repair with the insurance money from my wreck. Fortunately for me, my son-in-law's dad who owns a body shop is doing the insurance work. Coincidentally, his brother has been welding all his life. AND he isn't charging any labor to R&R the engine. So, I think we'll weld it up, put a plate over the area, and run it til I find the right motor. Maybe save up and just buy a new long block. Just can't justify putting too much money into a truck with a salvaged title.

Here's a suggestion based on a lot of searching I have done. Mine is cracked as we speak and I was going to do this repair, which should work if your truck is not to heavily modded. I would braze the crack with this brazing rod HTS-528 and then fill the block with hard block concrete block filler. You need to fill it about one to two inches above the crack and keep it out of the oil cooler area, let it sit for two weeks before you put the truck back on the road. It can be done with the engine still in the truck. The 53 blocks are about half the thickness of the other blocks in the areas that they crack in and this area is a very high stress point. If you look at the newer engines out there you will see that they have completely redesigned this area. The block filler will stiffen up this thin area.I should mention that the reason for the braze instead of welding is that you don't heat the block as hot, just cherry red. If you do decide to weld, then I would use Muggy Weld, with a TIG welder to help keep the heat concentrated in a smaller area. Make sure you drill the crack with either process.I just found a 56 block short block for 350, so I'm probably going to go that route, but a repair of the type I just mentioned is still being done on a friends truck, so we shall see.Good luck

So let me run this by you guys. Instead of strengthening the area from the inside, how about attaching (not sure whether to weld, bolt, or use adhesive) a plate to the entire outside area where they're prone to crack. Started thinking about this after talking to the guys at Lock N Stitch yesterday. They want to sell me three plates to cover the whole area because they say that once the cracked area has been repaired, another crack may occur. Yes, this is temporary but the engine is currently out so we have access to the whole area.

From all of my research, I would fill it. the block is thin in the back as well as along the cam gallery. There are two forces at work on this block. one of them is a twisting force from putting in in gear and hauling. The other is from the top half of the engine trying to separate from the bottom half. More fuel and more boost increases this force dramatically. If you look closely at the block, you will notice that the area they crack is, is where the block curves in to create the separation for the water jacket and the crank case. The top half of the engine is pulling with the greatest force along this curve. The new blocks carry the force all the way to the bottom, no curve. I should mention that these blocks were created to be lighter and they are almost half the thickness of others. 6-7mm vs 11-12mm If your truck does not have the crank sensor in it. I would recommend that you buy any block you can find, except a 53. I believe that all should be compatible, but you need to do a little research I even looked into getting a 6.7, but mine has the crank sensor and I didn't want to change the wiring harness and the cam gear as well as the computers. If you weld plates on the out side, you risk transferring the load somewhere else and having it crack there as well as creating heat stress through out the block. If you try to epoxy some plates on, the epoxy will crystallize over time and your back to where you started. If you use the lock n stitch system, they will not guarantee anything, and you wasted your money. For the price of the lock n stitch, you could buy a new block. (not a good investment) The block filler will cost you about 140 and the brazing rod will cost you around 70. you can add some more plates to the side of the block, but I wouldn't do it without filling the block. The block filler will transfer the loads over the widest area possible, everything else I looked at only moves the loads to other areas. This is based on the research that I have done over the last few months. I talked with the manufacturers of everything I could find.

Keep us up to date, just guessing here but I would say 9 out of 10 blocks will crack again. Lock and stich just told you it will crack again. Here's the problem, expansion and contraction, when you can control that you got it. Bolting all the plate in the world on the side of the block aint gonna stop it.If you ever get it sealed then keep the eng block pluged in it will keep it from contraction, then you might stand a chance.

My grandfather had a 53 block in his when i was about 15 it cracked right around 210,000 he and some army buddies got together and stitched it and it held for about a year (he put 50k on it that year) held good until the first good cold day in dec. (7 degrees) then cracked again even with the heater on so they replaced the block new from cummins block was about 1800 brand new thats what I would personally recomend

Whew!!! My repair shop finally found a motor. I sure wasn't looking forward to dealing with that 53 any more. Thanks for all the advice. I believe the guy at the body shop (my son-in-law's dad) is going to try to repair the crack and keep the motor. I'll pass all this info on to him. He's pondering the idea of putting it in an old Willys 4x4 waggon.

Nice. Another cracked 53 block ex owner. Glad you found another block.