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1980 720 L20B Hole in cylinder head. Check this out. Big PIC!


JWJohnson

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So, new to the forum, been wrenching for years, primarily Diesel's but gassers too. So I picked up the little pickup for $500 with 250K. It had a leaking valve cover gasket so there was very little oil left. So I pulled the v/c to fix the leak, got the cover off and saw the worst 'milkshake' I have ever seen in any motor. I don't have pictures of that though unfortunately. Just know it was horrible. I figured it is either A) Head gasket, or timing cover/ water pump gasket, both easy and cheap. So I started with the head, I got it pulled off last night set it on the table to be prepped for reinstallation and BAM! I found this little jewel in the photo... It is the passenger coolant oriface between #2 and #3 C.C's. I am going to see about just having it welded and machined but I might have a better chance at just buying a new head, or at least on that is good. Just gotta find one, anybody got an extra GOOD one laying around?

 

Also, have you ever found anything like this before? if so, what did you do?

 

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I though it was a drill hole at first but up close it is too uneven and pitted. Water could be a possibility, but it would show corrosion throughout the head and block... BTW Block looked clean, no issues with it with some degreaser and WD-40 and a couple shop towels was able to get 85% of the material on the block off. I don't have a tig and all the shops that are capable around here are like 4-6 weeks backed up.

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Anyone know where I can get another head? Only place I can find one that is going to work is on ebay. It is going to cost real close to the same to fix this thing as it is to buy a brand new one. The second and third cam towers only have one bolt in them as well.. I think they might have JB Welded them in place... This thing is in some pretty rough shape. I'm looking at $500 for a new reman from the local parts store... Closest pick and pull doesn't have it either... I hit up an auction on Ebay for one that had just come off a low miled '80 put in for like $65 but it still has a week left so who knows.

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I would rather keep it a W58 or the N56 as I don't want to change the manifold. I just need to find one around here that isn't brand new that is 'servicable' as well. I would do any of the others if I got a manifold to fit. I got my head gasket kit with both square and round manifold gakets.

 

I double checked and it is for sure a W58.

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I don't know how this thing lubricated itself... Two cans of degreaser, two cans of WD-40, picks and rags in every nook and cranny I could get my fat fingers in and still not even close to getting all the sludge out... This head is in some bad shape!

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You can see where it was moving 0 oil through it at some point.

 

It's crazy, I drove this thing home like this.

 

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Valves and springs removed, even the spacers were burned.

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Yeah that is an issue... But it had the same 'burn' marks I have seen in countless transfer cases and transmissions of high powered diesels. When you work them hard enough the lubricant gets so hot it burns the surface leaving a stain so to speak. The only way to get them out is acid wash it and even then it is hard to remove the stain and plus you risk damaging the parts if done improperly. Under the spacer/washers one the spring pedestals, it had the same burn/stain markings I have seen several times before. I'll take it in and have it flux'd and see if any of that will help it. I think it should help the sludge issues as well as a lot of the discoloration. Then go have it welded perhaps? I don't know. 

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The gasket lined up correctly and holes lined up. It was all correct just an erroded area. I'm not so sure they are coolant passages either. I think they are too small to be coolant. I am thinking the top/drivers side oriface is the failure for the milkshake.

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I know they are supposed to be there. I just wasn't 100% if they were coolant or oil. Well if they are for sure coolant, then I guess I will have to pull the timing cover off and see if that gasket failed. Between the most drivers side port for coolant and the smaller oriface is the only place I see any fluid transfer between the gasket and head. If it is traveling between two coolant ports then there isn't an issue with the head gasket.

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So got her all cleaned up and it is worse than I thought. There is so much corrosion all over this thing! I am going to take in and see if they can weld the corrosion out of it but for right now, I am skeptical. 

 

Here is the first hole just cleaner.

 

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All the rest of the coolant orifice's are pretty eroded as well. Think this might just be a paper weight.

 

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Everything else cleaned up decently.

 

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Even after a two day soak and a jet wash there is still sludge in the oil chambers.

 

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I believe if you have the head milled depending how deep all that is, (can't really tell) it should at the most part clean most of your edge corrosion. Not too sure about that pit though, but a machine shop should have a good idea about it.

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All of the coolant ports prodrude past the gasket surface. If it were put back on the block and continued to be used in operation it would only get worse causing another failure... So I just bought another one in a junk yard last night for like $75, kind of steep but it was in much better shape than the first one. Now that one is at the machine shop getting pressure tested, cleaned and milled flat if warped. 9 out 10 times, a high mile aluminum head is going to be warped.

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