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56ci OMC - Broke off all head bolts but 2
https://hpbc.ca/viewtopic.php?f=19&t=743		 Page 1 of 1
Author:  Hevi Kevi [ November 10th, 2012, 9:35 pm ]
Post subject:  56ci OMC - Broke off all head bolts but 2
Ok, I've worked on quite a few outboards from the 1930's and up and I have never run into this before. Trying to pull the head off my engine and snapped off all but 2 head bolts. Is this normal for these? It seemed to be a fairly clean looking engine when I started. Do I risk the chance of warping or cracking this thing if I heat it up a bit with the torch? I've worked on 4, 49.9's and never snapped one. Most broke off at the top of the head so I'm hoping when I get the head off, maybe I can give it some heat and get on what's left of the bolts with some vice grips. That is when I manage to get the head off :x
Author:  LittleCharger [ November 10th, 2012, 10:12 pm ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
Hevi Kevi wrote:
Ok, I've worked on quite a few outboards from the 1930's and up and I have never run into this before. Trying to pull the head off my engine and snapped off all but 2 head bolts. Is this normal for these? It seemed to be a fairly clean looking engine when I started. Do I risk the chance of warping or cracking this thing if I heat it up a bit with the torch? I've worked on 4, 49.9's and never snapped one. Most broke off at the top of the head so I'm hoping when I get the head off, maybe I can give it some heat and get on what's left of the bolts with some vice grips. That is when I manage to get the head off :x


Sounds like someone put them on with permanent thread locker as the spec torque is only 20lbs, it is common for them to come loose so that may have been someone's poor solution.
Author:  Hevi Kevi [ November 10th, 2012, 10:59 pm ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
I'm the first one to wrench on this one. The corrosion in the holes and even rust on the bolts made them stick. I've never seen any of the older ones have the bolts rust. I just pulled apart a 49.9 and they were all stainless. This one looks like they just used plated bolts. I guess I'm not used to working on newer stuff. I can only afford the old junk lol
Author:  Hounddog [ November 10th, 2012, 11:24 pm ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
If you have a spare damaged head, put in on and use it as a guide to drill out the broken bolts. Most times some heat, some oil and a left hand drill bit removes them without any damage to the block. You can buy studs, washers and bolts at CTC.
Author:  Hevi Kevi [ November 10th, 2012, 11:55 pm ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
Thanks. So enough heat to help get the bolts loose shouldn't harm the block? Drilling out the bolts won't be a problem but I'd just like to do it the easy way if I can. I've never had to put heat to one so I didn't know how sensitive they are.
Author:  Hevi Kevi [ November 11th, 2012, 12:24 am ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
Probably should have asked about heat in the first place. :oops: Would have made things a little easier
Author:  sharpeye Mike [ November 11th, 2012, 9:13 pm ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
If you have a mig welder you can place a nut ( same size or one size bigger ) on top of the broken stud and weld it on, the heat will force the stud to expand but since it has no room to expand it will shink when it cools and VOILA the stud will be loose again. I worked in a machine shop in my early years and this was an easy fix most of the time after someone broke an easyout in the stud. Hope this help.
Mike
Author:  Hevi Kevi [ November 12th, 2012, 12:52 am ]
Post subject:  Re: 56ci OMC - Broke off all head bolts but 2
sharpeye Mike wrote:
If you have a mig welder you can place a nut ( same size or one size bigger ) on top of the broken stud and weld it on, the heat will force the stud to expand but since it has no room to expand it will shink when it cools and VOILA the stud will be loose again. I worked in a machine shop in my early years and this was an easy fix most of the time after someone broke an easyout in the stud. Hope this help.
Mike



Last night I stood the block up on the mill and drilled all the bolts down to just above the top of the block to get the head off. I was going to drill and easy out them with some heat today but didn't have any time to work on it till tonight.

After you mentioned that, I remember a mechanic buddy of mine telling me he had done this. I tried it and VOILA. ALL of them out in like 15 min. Worked great!

I originally posted this because I wanted to vent and I was wondering how sensitive these blocks are to heat. I actually have a machine shop and I've drilled, used easyouts, left hand drills, drilled the hole to the tap drill size and picked the threads out with a dental pick. I also have a cutter grinder I use to make spade nose carbide drills out of old endmills or supercarbide to take out broken taps and broken easy outs. If all else fails then it gets EDM'd out. Obviously I don't know it all though, and I'm sure glad you gave me your input. That saved me a pile of time and I'll be sure to use that one in the future. :D :D
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