Cracked block

[wreckbuilder]

I've been gathering parts for a 408 bracket engine build. Found a bare 89 360 la block and was cleaning it up getting ready to take it to the machinist . We'll I noticed cracks and a slight bulge around the timing cover bolt hole. At first I thought had froze but that didn't make sense because the core plug was right beside the bolt hole and it had not moved. So I think someone put too long of a bolt in that hole and did the damage. Has any one ever seen this ? And my main question. Is this repairable? Would you trust it for my intended use? Thanks.

 

[RAT ROD AL]

I've heard that happens alot. I myself would find another block before spending $$$$at the machine shop.

 

[RAT ROD AL]

Cylinder look ok ?

 

[wreckbuilder]

Cylinder look ok ?

I ran a hone through it and there is a small shiny spot. But it is very low in the bore. I figured the over bore would take care of that. If it mags ok

 

[RAT ROD AL]

I've heard sometimes the long bolt will crack the cylinder wall .

 

[413]

Be glad you found it now, before any more time and money spent on this boat anchor of a block.

Start over

 

[RustyRatRod]

I ran a hone through it and there is a small shiny spot. But it is very low in the bore. I figured the over bore would take care of that. If it mags ok

It's a shiny spot because it's a high spot where a bolt that was too long was tightened into the cylinder. If it's about in line with the bolt hole with the cracks around it, there's your evidence. I agree. Find another block.

 

[wreckbuilder]

It's a shiny spot because it's a high spot where a bolt that was too long was tightened into the cylinder. If it's about in line with the bolt hole with the cracks around it, there's your evidence. I agree. Find another block.

Yeah there is no doubt its where the bolt contacted it. I hoped it might clean up with the cylinder boreing. But I reckon its not worth the risk. Cast iron dont usually just bend.
I will start over looking for a block I guess

 

[67Dart273]

Depending on what you have into it, and the cost of a second block, you could get that hole sleeved. Absolutely nothing wrong with a properly done sleeve, and you do not have to do all of them.

 

[1WildRT]

It's a shiny spot because it's a high spot where a bolt that was too long was tightened into the cylinder. If it's about in line with the bolt hole with the cracks around it, there's your evidence. I agree. Find another block.

1000% agree.. Sorry that ain't your 408 block...

 

[RustyRatRod]

Yeah there is no doubt its where the bolt contacted it. I hoped it might clean up with the cylinder boreing. But I reckon its not worth the risk. Cast iron dont usually just bend.
I will start over looking for a block I guess

Well.....Even if that cylinder is cracked from the bolt, it can be sleeved, so there's that fix. And "I guess" if you put a heli coil in that bolt hole with some red locktite, there's "that" fix. But then, I'm seeing like three other cracks. Is that about right? I suppose a good machine shop could fix all that, but what's another block and cost to prep it gonna run? Just something you gotta mull over.

 

[1WildRT]

Depending on what you have into it, and the cost of a second block, you could get that hole sleeved. Absolutely nothing wrong with a properly done sleeve, and you do not have to do all of them.

Yeah, a sleeve will fix the bore, but then ya gotta fix the front of the block, there is definitely water right there, so do you want to invest in that block & find it leaks? Or find another block?

 

[wreckbuilder]

Well.....Even if that cylinder is cracked from the bolt, it can be sleeved, so there's that fix. And "I guess" if you put a heli coil in that bolt hole with some red locktite, there's "that" fix. But then, I'm seeing like three other cracks. Is that about right? I suppose a good machine shop could fix all that, but what's another block and cost to prep it gonna run? Just something you gotta mull over.

Yes there are 3 cracks coming from the bolt hole one runs into the core plug hole

 

[MOPAROFFICIAL]

I'd find another block.. though the only thing you can do to fix is... machine thread plug , 2 overlapped. They do this with block decks and between chambers on heads. I have some ported high flowing j heads that been double overlap plugged between 2 cylinders due to a blown head gasket burning through and heat cracking/spider cracking. Works fine and no problems. New block would be best... but it can be fixed, I believe.

 

[GTX JOHN]

If it was a $4,000 race block = Then i would try to fix the problems.

For a $200/300 production block = Nope!

 

[jimjimjimmy]

i see you live in Tenessee just run it down to Uncle Tony and maybe he will flux core it for you .

sorry but i couldn't resist

 

[RustyRatRod]

I didn't see you were in Tennessee. Seriously, it would be worth the phone call at least to contact Hensley Motorsports. They might can actually fix it right.

 

[67Dart273]

Yeah, a sleeve will fix the bore, but then ya gotta fix the front of the block, there is definitely water right there, so do you want to invest in that block & find it leaks? Or find another block?

Sorry I did not see that

By the way to the OP, you mentioned the "freeze plug" did not move. Those are not freeze plugs, they are core casting plugs, and there is no guarantee that they will do anything. I once junked a great running 383 335hp that someone had swapped into a 64, complete with the HP manifolds, that I was told was cracked. I checked the oil, looked great so I started filling it with water. LOLOL. It never quit!!! The water went in and disappeared, and pretty soon the block was full. I pulled the intake and the "V" of the valley was cracked in several places above the cam on each side. The core plugs looked great!!!

 

[Max1196]

I agree to the different block, sadly, this does happen.
Any bolt will do! a post i did years ago

 

[wreckbuilder]

Sorry I did not see that

By the way to the OP, you mentioned the "freeze plug" did not move. Those are not freeze plugs, they are core casting plugs, and there is no guarantee that they will do anything. I once junked a great running 383 335hp that someone had swapped into a 64, complete with the HP manifolds, that I was told was cracked. I checked the oil, looked great so I started filling it with water. LOLOL. It never quit!!! The water went in and disappeared, and pretty soon the block was full. I pulled the intake and the "V" of the valley was cracked in several places above the cam on each side. The core plugs looked great!!!

Thanks I understand what you are saying. But it is obvious that a bolt that was too long did the damage beside what I refered to as a "core plug"

 

[wreckbuilder]

Well thanks everybody, I am looking for another block.

 

[Oldmanmopar]

Try and find an early block The cylinder walls are thicker. 71-74. The Block you have can be welded but that cylinder should also be sleeved . I am pretty sure if you have it magnafluxed you will see a small crack in the cylinder where the bolt pushed.

 

[Ironmike]

No matter what you do to that block, it'd gonna leak water...... Although for a race car maybe you could Hard fill it?

 

[1WildRT]

Try and find an early block The cylinder walls are thicker. 71-74. The Block you have can be welded but that cylinder should also be sleeved . I am pretty sure if you have it magnafluxed you will see a small crack in the cylinder where the bolt pushed.

The 89 is probably a roller block.. Which is exactly what I would be looking to replace it with...

 

[cosgig]

I have probably the exact block you want, but I’m here in Michigan. It belonged to a member here who passed away. He was building it for his Dart Sport, it’s standard bore, he had it honed and ready for some standard bore pistons, but never got it together. The problem is that the main caps were misplaced by the time I got over there to help clean out his Mopar stuff before the family got kicked out of the house. It’s a nice clean block, and would be perfect for your plans. If you’re interested in it, I’ll shoot a few pics tomorrow when it’s light out, it’s in my other shop. Obviously, unless you’d like to road trip up here, or my Mom and her husband are going to Florida soon, it would have to be shipped. I’m almost positive it is an ‘89 block. Message me if you’re interested in pursuing this.