Cracks between head bolts and coolant passages

[CudaRay]

I have a 318 that I was going to overhaul, but after washing up the block, I noticed these cracks. The cylinders are good, the only cracking is between the bolt holes and coolant passages. This car will likely see about 2500mi per year, and will make roughly 300hp.

I imagine this is probably junk, but I'd have to double my budget to remedy this with a new block near me. I'm not sure if it's good to send it with just a reduced lifespan, or maybe repairable. I did see this engine running before it was pulled from a d150, so who knows. The cracks are at the centerpoints of the passages, its all 4 of the upper bolt holes.

Is this a common thing with 318s or la small blocks in general? Has anyone ran an engine with this kind of damage?

 

[RustyRatRod]

Time for another block.

 

[CudaRay]

Time for another block.

Not what I wanted to hear, but I figured it's what has to be done. A shame, was in this whole thing for under $1,800 with a new a904 included.

 

[GTX JOHN]

318 blocks and even shortblocks are easy to find.
Usually, a $100 bill will buy a nice one out west!

Too bad you are back East = around 50+ Mopar Blocks laying
around my shops.

 

[RustyRatRod]

Not what I wanted to hear, but I figured it's what has to be done. A shame, was in this whole thing for under $1,800 with a new a904 included.

If you ever wanted a 340 or larger, now's the time!

 

[CudaRay]

318 blocks and even shortblocks are easy to find.
Usually, a $100 bill will buy a nice one out west!

Around here (and 3hrs around) the best deals I can find are around $350 for a block. One or two for $100 that need the machine shop. I have no clue why they're so difficult to find.

 

[CudaRay]

If you ever wanted a 340 or larger, now's the time!

I'd been looking for a 360, but the cheapest I can get one around here (whether built myself or buying complete) is 2k-3k. Even 318s are several hundred for a block.

 

[Illahe]

I have a 318 that I was going to overhaul, but after washing up the block, I noticed these cracks. The cylinders are good, the only cracking is between the bolt holes and coolant passages. This car will likely see about 2500mi per year, and will make roughly 300hp.

I imagine this is probably junk, but I'd have to double my budget to remedy this with a new block near me. I'm not sure if it's good to send it with just a reduced lifespan, or maybe repairable. I did see this engine running before it was pulled from a d150, so who knows. The cracks are at the centerpoints of the passages, its all 4 of the upper bolt holes.

Is this a common thing with 318s or la small blocks in general? Has anyone ran an engine with this kind of damage?

View attachment 1716474691

View attachment 1716474692

I've had two blocks with that issue. Both were early hydraulic roller LA. Chuck it!

 

[CudaRay]

I've had two blocks with that issue. Bothe were early hydraulic roller LA. Chuck it!

I'm seeing so many people using a high temp JB Weld on these cracks that I'm considering just putting it together and seeing how long it lasts. It would at least let me put all that money toward a big block.

I can't be sure just how much of a potential issue that would be for a car that'll be driven maybe 150mi in a month.

 

[volaredon]

dont waste your time. JUNK IT youre not looking hard enough if you say what you do about a 318 being hard to find. Look at CL, MP, your car buddies...
Whatever you do DO NOT DO NOT DO NOT JB Weld a block unless its for a coffee table or some such display.

 

[CudaRay]

dont waste your time. JUNK IT youre not looking hard enough if you say what you do about a 318 being hard to find. Look at CL, MP, your car buddies...
Whatever you do DO NOT DO NOT DO NOT JB Weld a block unless its for a coffee table or some such display.

Fair enough I suppose. I've got MP on a 250mi radius, they're on there, just several hundred for a tired block.

CL is completely empty, and I'm 24 with no car buddies, so that's out of the question, haha.

 

[TT5.9mag]

Doesn’t really matter if you drive it 10 miles a year or 10,000 miles a year. When bolt holes are cracked like that the clamp load of the fastener is severely reduced. That means your head gaskets don’t seal. It’ll run until it heats up then start eating coolant. Get rid of it.

 

[George Jets]

Are you sure that is an actual crack and not just a water trail from a very old head gasket?

Put some 180 grit on a sanding block and sand over it a few times and see if that line disappears.

Worth a try, a person would feel awefully stupid if it was just a water trail from a head gasket starting to go bad.

☆☆☆☆☆

 

[Plymouth 65]

If you were closer I'd give you a good 318 short block. 65

 

[CudaRay]

Are you sure that is an actual crack and not just a water trail from a very old head gasket?

Put some 180 grit on a sanding block and sand over it a few times and see if that line disappears.

Worth a try, a person would feel awefully stupid if it was just a water trail from a head gasket starting to go bad.

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☆☆☆☆☆

I'm pretty sure its a crack, it's on both sets of jackets, on both sides, and I can see a line going down on the insides. I'll try it regardless just in case though.

 

[Newbomb Turk]

Are you sure that is an actual crack and not just a water trail from a very old head gasket?

Put some 180 grit on a sanding block and sand over it a few times and see if that line disappears.

Worth a try, a person would feel awefully stupid if it was just a water trail from a head gasket starting to go bad.

View attachment 1716474721


☆☆☆☆☆

It’s a crack. Virtually 95% of blocks with that water core in them fails. They are garbage.

 

[ocdart]

@CudaRay, have you tried contacting a local Mopar car club in your area? One of their members may have something available.
Here's a link to one in the Wichita area I found on the web...

Contact – Wichita Area Mopar

 

[George Jets]

I'm pretty sure its a crack, it's on both sets of jackets, on both sides, and I can see a line going down on the insides. I'll try it regardless just in case though.

Was just reading lately around 1980 - 1981 they lightened up the 318 blocks, wonder if that had something to do with them cracking around the head bolts?


☆☆☆☆☆

 

[RustyRatRod]

It’s a crack. Virtually 95% of blocks with that water core in them fails. They are garbage.

That's been my experience, too. It's ONE style of core that does it and that's it.

 

[RustyRatRod]

Was just reading lately around 1980 - 1981 they lightened up the 318 blocks, wonder if that had something to do with them cracking around the head bolts?


☆☆☆☆☆

It's a good possibility. The early ones like we're always touting are just overkill badassary that they should have kept making. It's sad, but I wonder how many of those have been scrapped "just" because they were a 318?

 

[Kendog 170]

Post a wanted ad. Maybe you'll get lucky from a member nearby. It can't hurt.

 

[Locomotion]

Since you can't be sure if the cracks are from a bad casting, over-torquing and/or overheating, double-check the heads for cracks also.

 

[jimjimjimmy]

I bet the heads are cracked between the valves also .

 

[CudaRay]

@CudaRay, have you tried contacting a local Mopar car club in your area? One of their members may have something available.
Here's a link to one in the Wichita area I found on the web...

Contact – Wichita Area Mopar

That's good idea! I did find a seemingly good block for $100. Balancer bolt broke causing the crankshaft to crack. Supposedly no ridges in the bores and no visible cracks. Only problem is its over 2hrs away.

 

[CudaRay]

Since you can't be sure if the cracks are from a bad casting, over-torquing and/or overheating, double-check the heads for cracks also.

I have some nicer heads off my old 76 block that I was going to use. I found 302 heads for $150 that I may still buy. Same guy from my last comment, 2.5hrs away.