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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: fixits on November 17, 2011, 01:53:21 pm
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Hey all:
First thanks for all the warm welcomes to the forum, its very much appreciated.
Now on the the fun. Quick history on the truck, 16 yo daughters dream vehicle '82 K10 SWB with 77k origignal miles on a 5.0. She has had for about 5 months and put only about 1k miles on it. Been running fairly well but had a little miss we couldn't quite tune out. Starting using coolant and running poorly..white, sweet exhaust smoke. OK..time to teach her how to replace the intake gaskets..tore that down and no obvious leaks..decide to keep going and pulled the heads.
Bingo..#1 obviously blown. On further inspection I see that the front indexing pin is mushroomed and only sticking up about 1/8" above the block..rear is fine. I firmly believe that this head has never been off and this motor left the factory with this issue...maybe that is why it only had 77k on it? The head was just never fully seated on the deck. also know that it wasn't using any significant coolant with the last owner and took the heavy foot of a 16yo to finally kill an already wounded gasket. This truck hasn't ever gotten hot since we have owned it and burns no oil. Motor is super tight.
Upon cleaning up the heads and preparing to reinstall (replaced the pin) I notice a crack. Crap. An inspection of the crack, head and block I see absolutely no indication that this crack has created any internal coolant leak because its between the water jacket and a head bolt hole. I best guess is that its a stress crack created from the head not being fully seated on the deck and it cracking when the head bolts were torqued down.
I already have these things off, her coffee shop job creates a tight budget for her so looking for suggestions.
Replace the head?
Have the crack welded?
Put it back on and hope it goes another 77k miles?
I live in an are where there are not machine shops on every corner so not really sure how popular the repair option is and what the cost would be?
I already know what everyone is going to say but lets just throw this out there and see shall we??
(http://i366.photobucket.com/albums/oo103/45acpfan/IMAG0355.jpg)
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if it was me, and I had a tight budget, I'd ignore the crack and see what happens.
Or, with a little more budget, If you have a wrecking yard nearby and can afford a used (warranted) head, get one that matches and use it after putting new seals/valves in. Those heads should be everywhere.
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Get it welded if possible, it should be fine. Otherwise do what the guy above me said ^
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I don't know what heads would have come on your truck but Maybe you can find a set of camaro heads or similiar with a higher compression ratio to step up the performance and mpgs a little since you have them off and you know they might be an issue. maybe someone here can add a little info as to weather this might be an upgrade or not or just do a little research.
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Well..after looking at it really close and my daughter deciding she didn't want to owe me $$ until she was 22 we decided to just reinstall it. If this thing gets any longer its just going to find its way into the opposite water jacket.
Will let you all know how we did tomorrow...
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Sucess!. So far she has put about 500 miles on the truck since the new head gaskets and every issue we have had with using coolant, missing under power and rough idle are all gone. Will update this thread if we encounter any issues in the future but as of now things are great.
Thanks again for the input.
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Good to hear... Back about 28 years ago I bought a 72 Buick with a hairline crack between the freeze plugs that on the passenger side. I put 2 packs of that silver powder stop leak, (about the size of a roll of quarters) and it sealed it. I drove the car for 2 years with no problems before I sold it. I have fixed several leaky radiators over the years as well, it has worked great in all but 1 instance as it didn't seal up a bad heater core...
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I hate to be negative but I don't see new head gaskets making a lasting fix on this. Seems much more likely to be very temporary.
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IMO where the crack is located should not present a problem. I would sugest a little bit of JB weld if u are truely concerned. I have raced an sbc with a crack thur the water jacket, after jb it never leaked and is still in operational condition
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I don't take it as being negative. I appreciate the input, that's why I posted here so I could get different ideas and opinions. The head gasket was certainly the problem because it was blown at #1 cylinder. I fully believe that when the engine left the factory the head was never fully seated to the deck. There were indications that this was an old problem.
2000 heavy footed teenage girl miles and still running perfect and not using any oil nor coolant. Time will certainly tell..
I hate to be negative but I don't see new head gaskets making a lasting fix on this. Seems much more likely to be very temporary.
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That looks familiar! I ended up getting a set of heads from a family friend and took the to a machine ahop for valve seats and seals. It cost me 200, but the job was 400. The machinist told me he cut the price in half because he didnt know if he missed the crack when I took my engine to him a year early for a rebuild.