318 Engine scratch/pitting

Dave Unrau · Nov 30, 2020

Just looking for some advice on whether or not to rebuilt this engine block because of this defect. I am not building a race motor, I am building a motor slightly over stock as a trial for myself to see if I can. This

defect is not very deep. I also am trying to avoid machine shop work and build a budget motor reusing as much as I can, hopefully these pics work

Meep-Meep · Nov 30, 2020

Head gasket needs to seal so if that defect creates a tunnel under the compressed steel rim then you may have a problem. What you might consider (being on a budget) is first cleaning that out with a wire brush and/or chem process to really see how far it goes. If it's severely pitted try filing off some iron from a spot on the outside of the block and mix with JB weld and "bondo" it up. What's the worst that can happen? The gasket leaks and you pull the engine. Yes, lots of work so you decide. Or the patch works. FYI: I ran a Toyota 22RE for 30K miles with the aluminum head eroded into a water passage using Bars Leaks so you might be surprised what you can get away with. I knew this because eventually I pulled the head and saw the damage that required welding to fix.

mopar 3 B · Nov 30, 2020

If it gets into ring travel and so deep that it needs to be cut out. 318 blocks are cheap.

vance.dykes · Dec 1, 2020

get new gaskets and see what it covers . if it came apart that way with no problems then it should be ok.

68Moparmaniac · Dec 1, 2020

Hard to tell how deep that blowout is by your pics. If its only .030 - .050 deep you may get by with just decking the block but if it strikes the water jacket your looking at a welding job. It probably can be fixed if your willing to spend the bucks on a patch job. Someone who knows how to weld cast iron could get it done reliably, then the machine work to reestablish the bore and deck surfaces. $$$. If it was my problem I'd dig around in the junkyards for another block...probably cost a couple hundred bucks out the door but then the repair job will cost you that much so....
I agree with mopar 3 B, 318 blocks are cheap.

mtbase · Dec 1, 2020

It appears to be porosity in the casting.

As long as the gasket encompasses it completely...I wouldn't do a thing.

Welding will likely open a can of worms if you get too close to the bore. I would have expected to see a witness of exhaust escaping in that area, if this was a "real issue"...unless you cleaned it off.

69Bee · Dec 1, 2020

Casting porosity. I just did a slant six that had that in a cylinder and ended up sleeving the hole. The more I bored (for the sleeve), the worse it got. As long as the pocket is inside of the fire ring, there is not an issue. Hell, it has worked for at least 30 years so far. If you just don't feel comfortable with it, install a sleeve, and pin the deck to fill in the void, then bore the motor to the next size, square the block, and don't look back...

mopar 3 B · Dec 1, 2020

If you were not so far away I would almost give you a block. That is how valuable they are here. Personally I would not take the chance with that block. But 318's are still plentiful here.

Dave Unrau · Dec 1, 2020

Thanks for the info, it may be hard to tell from the pic but the defect is not very deep (.010) ish so I'm thinking some Ultra copper in that spot might work when I'm putting on the head gasket. Again, this is a low budget, first time building an engine to learn so I can build another learning as I go. I have a 1987 roller cam and this a 1973 block.

69Bee · Dec 1, 2020

Dave Unrau said:
Thanks for the info, it may be hard to tell from the pic but the defect is not very deep (.010) ish so I'm thinking some Ultra copper in that spot might work when I'm putting on the head gasket. Again, this is a low budget, first time building an engine to learn so I can build another learning as I go. I have a 1987 roller cam and this a 1973 block.

Please don't use ultra copper on the gasket or deck. If the void is inside of the head gasket fire ring, you will be fine...

dvw · Dec 2, 2020

My current race motor has pits in the deck surface filled with JB weld. 15-1 compression. No issues.
Doug

318 Engine scratch/pitting

Dave Unrau

Member

Meep-Meep

дворянин

mopar 3 B

Well-Known Member

vance.dykes

Well-Known Member

68Moparmaniac

Well-Known Member

mtbase

FBBO Gold Member

69Bee

FBBO Gold Member

mopar 3 B

Well-Known Member

Dave Unrau

Member

69Bee

FBBO Gold Member

dvw

FBBO Gold Member

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