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Discussion Starter #1
I basically need to know if I'm haning onto this block for no reason.

What happened is I had a 402 that broke a ring and goofed-up a cylinder. Some guy on Craig's List was listing a 396 block for free....with 781 heads. Of course, I hopped right into the car and picked them up. When I got home, I started looking real close at the block. I got out my caliper and found out is was a 402. What puzzled me was that the cylinders looked like they had just been bored but not finished honed. The top edges of the holes are super sharp with no carbon lip at all. The deck stamped numbers are gone too. I soaked on cylinder with wd40, and wiped it out good. It looked like I could see some rough machine marks that were uniform. Cylinders feel super smooth.

I don't know how much rust is too much on a block like this....and I also don't know how to clean it. Is there a change that someone punched this thing and then made the mistake of setting it outside to rust??? Obviously, where I am going with this is that it would be so cool to be able to clean the block and then get the rust out of the piston and lifter holes with a hone, get some new rings and throw my 402 roatating assembly in it to get a budget motor for another one of my projects.

Look at the pics and tell me what you think.










 

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I would find a machine shop with a Hot tank and stick it in there for like a week and see what it looks like afterwards, hopefully most of that is just on the surface and with a good bath it will look a lot better.

I'd also check to see how straight and true everything is, if hasn't been warped from the exposure you can probably save the block.
 

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Discussion Starter #3
I'd also check to see how straight and true everything is, if hasn't been warped from the exposure you can probably save the block.
I kinda figured that at least that would have to be done. The goal is to try and save on the machine costs. If it has to be re-bored, I'd pick a bigger inch motor with 4 bolt mains to put that kind of money into.
 

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I would definitely at least have it honed but it really depends on what the cylinders look like after they are cleaned up. Probably magnafluxed or sonic tested as well, hard to trust a block if you don't know its history.

I found most of the time after all the (machine) work that needs to be done all older blocks you are close to the price of an after-market block anyways (least getting close to 1/2), so not really worth the expense. I got away with it on my junk yard GenV 454 block because I was able to do all the work myself taking at class at a local CC (hot tank, magnaflux, sonic tested, grinding for clearancing pistons, deck and squaring etc)
 

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I'd scrub her down w/ some wire brushes and then dingle-berry hone her in the cylinders and use a brake hone in the lifter bores, then take her to a car wash and spray her down good!!

And don't be supprised if the bores don't rust before your eye's again, wipe her down w/ at least ATF OR good old MMO.. WET............

Bring her home and use an air compressor to blow her as good a dry as you can..

Been there, done it several times fine..

pdq67
 

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find a machine shop that has what some people call a "shake and bake" system.it heats the block to burn off any loose crust and then it goes in a cabinet where it will rotate while 2 paddles spin at high speed and sling real small steel shot everywhere.its like sand blasting,but uses steel shot instead.30 minutes in that cabinet and rust will be gone and it will look like new shiney cast iron,and then you can see every rust pit on it to see what you have.we have this system in our machine shop and it works great.any block that goes in,comes out looking like new.no matter what it looks like going in.
 

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Discussion Starter #8
find a machine shop that has what some people call a "shake and bake" system.it heats the block to burn off any loose crust and then it goes in a cabinet where it will rotate while 2 paddles spin at high speed and sling real small steel shot everywhere.its like sand blasting,but uses steel shot instead.30 minutes in that cabinet and rust will be gone and it will look like new shiney cast iron,and then you can see every rust pit on it to see what you have.we have this system in our machine shop and it works great.any block that goes in,comes out looking like new.no matter what it looks like going in.

What suck is that I live in a rural area that doesn't even have a sonic setup. That's why I was thinking about the soda blaster at my local powder coating shop.
 

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My 454 cylinder walls looked much better than that and it had to go .030 over. Some water was in the cylinders in just a small spot and that was enough to leave a little bit of pitting. Any pitting and its time to bore them out. It was sad because you could still see some faint crosshatching in the cylinder walls. You could barely feel the pitting with your finger tips.


 

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find a machine shop that has what some people call a "shake and bake" system.it heats the block to burn off any loose crust and then it goes in a cabinet where it will rotate while 2 paddles spin at high speed and sling real small steel shot everywhere.its like sand blasting,but uses steel shot instead.30 minutes in that cabinet and rust will be gone and it will look like new shiney cast iron,and then you can see every rust pit on it to see what you have.we have this system in our machine shop and it works great.any block that goes in,comes out looking like new.no matter what it looks like going in.
Be very careful using steel shot to clean blocks. I work in a machine shop that shot blasts its part with steel beads. The beads get magnetized and are almost impossible to get off the metal parts. When you try to blow them off they just roll somewhere else. Hastings Rings web page has a service bulletin on this.
 

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Looks like someone's cleaned up the casting flash in the lifter valley drainback holes. There's a chance it was bored but not honed. If you feel a lot of tiny ridges, that may well be the case. Since it's dry, you can spray it down good with muriatic acid. It'll eat the rust and leave the metal alone. At any rate, you're going to need to have a machinist take a look at it sooner or later...
 

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Since it's dry, you can spray it down good with muriatic acid. It'll eat the rust and leave the metal alone...
Big can, even if half the block fits into it, leave overnight, hot rinse in the morning.

Dub, it needs a caustic vat. The water jacket and oil gallery is why.
Exactly, don't forget to scrub the galleys. Any dirt left will go through the bearings to the crankcase.
 

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Bigblock1969rs,
Where was that school where you were able to take that class? That sounds like it would be a great place to absorb some knowledge and really use some nice machinery. I gotta look to see if my cc has one. A little jealousy here.
 

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we have used this steel shot system for over 10 years and have NEVER had anything magnetize and stick to a block...you preheat block or heads to 300 degrees and it prevents beed retention.with freeze plugs removed it will also clean inside water jackets.the system was originally built buy a company called AMPRO.it is now owned by SUNNEN.SUNNEN does'nt mess with junk.if this system caused all these problems,then SUNNEN would'nt have bought the old company......
 

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Bigblock1969rs,
Where was that school where you were able to take that class? That sounds like it would be a great place to absorb some knowledge and really use some nice machinery. I gotta look to see if my cc has one. A little jealousy here.
I'm lucky in Southern California a lot of local Community colleges have really good automotive programs with full automotive and machine shops.
 
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