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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: christopher on October 15, 2011, 08:21:43 pm
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Here is the situation
1982 Chevy K20 350, 4WD
The lower alternator bolt broke off about two threads into the head. So they drilled it out, but they used a bit too big so a helicoil would not work.
Their solution was to grind down a nut drill deeper into the head and JB weld the nut into the head. However in this process they drilled into the water jacket of the head. I'm not sure this is a lasting fix
Is there a better way of repairing this or an I looking at new heads.
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Who is "they" that butchered your poor engine like that? Welding cast iron is a pain because of the prep and you have to preheat it, etc etc. but, I would make whoever destroyed your head buy you either a replacement head for the one they messed up, or even a pair of heads. I would never use jb weld as anything more then a temporary fix to get me by until I can repair it properly, like a cracked water pump.
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"They" is a long story. basically a hack Mechanic who thinks he know everything. The odds of getting anything from him are slim.
I was such a good running engine too. thank you for your input. Looks like I'll be pulling the heads.
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If you consider him a "hack mechanic" then I would steer towards a new person to work on your vehicles. If he was smart, he would have drilled a hole trough the middle of the bolt and used an easy out. Good luck with the new heads. Ive been down a similar road before.
http://forum.73-87chevytrucks.com/smforum/index.php/topic,20691.0.html (http://forum.73-87chevytrucks.com/smforum/index.php/topic,20691.0.html)
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1st why only 2 threads? And yes I would of tried a ez out or reverse bit for that one. Second if I understand you right he wants to drill a bigger hole then jb weld a nut in the hole? I can see this working but I wouldn’t do it. i think there was someone on here a while ago who did almost the same thing
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I do believe they did try an ez out. but gave up. Whatever there reasons they ruined a perfectly good head. I am really beside myself with frustration. That engine was the best thing about the truck. I mean it wasn't fancy or high power, but it ran so well. And I usually never let anyone else work on my vehicles.
WOULD THESE WORK? I have heads from a 68 Corvette. The engine had a blower . Not sure if they are stock to the car. from what I gather about blowers beside better valves, its likely that do not have any special machining. if they do work what head gasket would I use?
Thanks again
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WOULD THESE WORK? I have heads from a 68 Corvette. The engine had a blower . Not sure if they are stock to the car. from what I gather about blowers beside better valves, its likely that do not have any special machining. if they do work what head gasket would I use?
You never really know what kind of heads someone may have used when building a blower motor but you're right, no special machining would have been required because the blower is doing all the work.
Since your existing motor ran so well, it would be nice if you could get a head (or heads) the same type and CC as what you have now. Check the ID number that is cast into the area by the rocker arm studs. You can look that number up on the internet and it will give you all the information about that head. If you could find an exact match, you'd only have to change one head.
As far as what head gaskets to use, just use any high quality gasket such as a Fel-Pro or something and torque them to the correct specs.
I'd be very frustrated too, but you can't turn back time. What' done is done and all you can do now is get it fixed. I hope that part goes well for you. Sorry it happened.
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Do those 68 heads have the accessory holes for the alternator?
Your mechanic is not a mechanic, he's a menace so stay away from him. Vortec heads are a nice inexpensive upgrade and a vortec intake not too bad either.
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Thanks for your input and understanding. It took a few angry hours to realize you can't tun back time.
Anyway yes the blower heads do have a alternator accessory holes, that what gave me the idea to switch.
The blower was stolen (stripped), another long story, however a Edelbrock manifold and carb were added, (without thought to changing the can) so I was thinking of taking the whole top end and put it on the truck.
looks like i have some research to do.
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For sure scrap the head if it is drilled all the way into the water jacket. Like Vile said...good time to upgrade seeing how you need to spend some money anyway. If you use the 68 head I would still send them to a competent machine shop and have them go thru them just to make sure nothing is wrong with them. They should be able to tell you what you have in them also. Good luck.
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Without a photo it's a little difficult to vizualize your situation. What do you mean the hole drilled was too big for a helicoil? IIRC, they come in various sizes. Do you really mean the helicoil would be too large a diameter for the stock alternator bolt? If that's so, could the bracket (and its bolt sleeve, if so equipped) be modified for a larger, new bolt to fit the helicoil? If so, you could use a thread sealant on the new sized bolt like is used for head bolts going into the water jacket and likely cure any antifreeze leak fairly inexpensively. Replacing the heads on an otherwise great running engine would be my last resort.
My $.02
Rusty
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here is a picture of the hole with the nut removed and the left over jb weld.
I'm going to pull the head and bring it to a machine shop to see if it could be brazed or welded. and then re tapped.
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I'd wanna cut that guy in ways that'd make him useless to a woman... in the future, I'd do the work yourself, grab a chilton's guide and go to work.
A proper machine shop can probably fix it, an automotive machinist would be the best, since they work with cast iron all the time.