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cracked engine block


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I own a 82 king cab 4x4 720, yesterday I was told the engine block is cracked. I'm a college student and don't have time to fiddle with this thing anymore. The truck is in great shape, aside from the engine, typical rust on the wheel wells in the bed but the frame is solid. I absolutely loved this truck! What are my options? I'd hate to take it to the crusher so I'm seeing if anybody has any other idea's? Thanks guys!

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....... who told you its cracked?

 

 

, whats hapening with the motor that makes you beleive its cracked?

 

 

What's being done to it that someone says it's cracked?

 

whats going on with the motor that makes you think it has a cracked block?

 

 

And the answer is......

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I think cracks are over rated to begin with. Mechanics and engine builders have a vested interest in finding them to make more work and in order to guarantee their work. A crack is a relieved stress and that's the end of it. Many cracks that are found are perfectly fine running motors (in need of rebuilding, yes) but otherwise unaffected by any, andt have likely been there for years. If you look hard enough there are likely cracks on many to most old L/Z series locks driven daily. I have never once heard of an engine taken out of service that failed from an undiagnosed 'crack' that caused loss of coolant or oil, or had the head bolt pull out. In most cases the 'rod through the block' was from owners that failed to keep oil in their motors or continued to drive without oil or when over heated. The rest would have been motors that were just 'worn out' and seriously in need of new bearings or a re-build, or abuse.

 

Having said all that, for a performance engine (high compression, turbo) that is going to be built up and make serious power for racing, then I would have to re-think what I would consider minimal cracking around bolt and /or water jacket openings. For the most part they are benign and many owners have them and don't know it or want to know because their motors run just fine. What a shock it is to find it rejected by the builder after 30 - 40 years of reliable service.

 

This is just an opinion and does not apply to wrecker motors that have been sitting for 15 years with frozen rain water in them every winter.

 

oh, morning Hainz.....

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wow, you guys are on it! So here's what happened exactly,

2 days ago I picked up my truck from a shop who replaced the head valve seal, drove it about 20 miles and it started making a weird shaking noise like there was a part loose coming from the drivers side of the hood. I started loosing power, the noise got louder and i pulled over, once pulled over the truck was smoking pretty bad. I left it there for a couple of hours, I came back with my neighbor who's been helping me deal with the few issue's the truck has had. We poured antifreeze into the radiator and watched it all drip out the bottom, we found the radiator hose that connects into the base of the carburetor had a big hole in it, towed it to the garage and replaced the hose, then my neighbor calls me and says bad news there is water in all 4 cylinders and the only way i know that could have happened is with a cracked engine block.

Sorry it took me a while to respond, yes I am in school full time and I work full time.

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my cracked (crack used loosely) block story

 

bought a 92 camaro of craigslist, nice looker. got there and there was 4 other people that showed up while i was there looking at it (probably plants) test drove it pretty hard, seemed alright. so I swooped it up for a grand, thinking at worst I could flip it since there was so much interest.

 

that night drove it hard for about 40 miles to shake it out, everything is fine. pleased with purchase.

 

drove it to work next day, park it and coolant is dumping on the ground. put in the air and there is a fist size whole in the water jacket under the left exhaust manifold, they jb welded a hunk of metal over the hole........ lasted long enough to sell it and for me to drive it about 100 miles

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Cracked block almost never puts water in all 4 cylinders. A blown head gasket (and with it overheated that badly, it did) can, as can a blown manifold gasket. I've bought cars that had both situations. Both had NAPS-Z engines. And the blocks were fine.

 

I would suspect the head is warped beyond all hope though. NAPS-Z heads warp easily, and they aren't worth milling when warped because the cam bore won't line up anymore.

 

(You can tell there's water in all 4 by having it hydrolock, then pull the plugs. The car that had the blown manifold gasket, I pulled the plugs then turned it over and it shot water/antifreeze 15 feet in the air, dousing the 2nd story window of my house)

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Z24s are notorious for blowing h/g but the Z22 to a lesser degree. Any overheating is to be avoided at all costs! Sounds like you lost coolant and simply overheated and the head will warp and the gasket will blow.

 

You can:

 

Replace the head gasket and hope the head isn't warped or only slightly warped and will hold.

 

Have the head checked for warpage and lightly milled to level it, new gasket.

 

Replace with a used head from a wreckers. (check for warpage first) Note: this head is an unknown, could have bad valves and seals.

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As what Mike said, most cracks aren't that important, especially on a ho-hum regular motor. Race motor, no, cracks are not acceptable. When I dropped off my block to have the rest of the machine work done Mike at Sunwest even said those really won't matter, but I had seen them and I don't like cracks, so I had them welded up and the block surfaced, just enough to get rid of some scratches on the deck. Here are the before pictures. I'm going to pick up all the stuff in a little bit.

 

z24cracks.jpg

 

z24cracks2.jpg

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So according to all of your responses, my truck still has value! Here's the deal, it's cold in Denver in January and I don't have a garage or any tools so realistically I can't fix this problem without a mechanic any recommendations for datsun mechanics in Denver? Or what would any of you pay for a truck in this condition?

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