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Any other Heli-Coil junkies in here?

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  • Any other Heli-Coil junkies in here?

    I was just digging through some bolts looking for info for another post here and came across my "heli-coil box". It's a little plastic storage tote with nothing but heli-coils, the tools & taps for installing them, the taps for the size hole they are repairing if i just want to make a new hole and thread it and the drill bits for all the above combos. I do mainly metric so i keep m6 x 1 ...M8 x 1.25 and M10 x 1.25 and of course i have a few standards 3/8 x 24 .. 7/16 x 18 and one other one.

    When I build an aluminum block or head engine if the customer is up for it and knows what i do about aluminum and threads I'll do a complete block or head if they have the money for it (some do) and then i just feel like it's "built ford tough" LOL

    Personally on my car i do as many as i can in spurts when i have something off or have a head machined or anything like that. aside from wishing i could find an easier way to bore the new hole straight, it is for some reasom, something i absolutely love to do...kinda weird i gues but oh well

    So anyone else nuts over heli-coils ?????

  • #2
    I cannot even imagine it. I would spend my hard earned money on studs LONG before I wasted my time cutting out sevicable threads only to install repair threads right back into aluminum, only bigger.

    Once you have installed a heli-coil and it strips you have a real problem.

    As far as doing all of an entire assembly by hand after it was done by a precision mill?? Even if you was to do this with a bare block in a big mill it would need to be designed into an assembly because you are cutting so much meat out of an aluminum part only to still impart a twisting force on it.
    Studs eliminate twisting force and have to be pulled out vs stripping.

    IMO user installed heli-coils are a method to simply "get by" when something goes bad wrong. Factory installed steel thread inserts are application specific and are the correct length for the bolt and installed during production. It just is not the same.

    If I was gonna do something THAT crazy I would drill/thread the block out to accept bigger STUDS and then drill out the heads to accept them.
    Just my opinion tho...YMMV

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    • #3
      X2

      HC's are used by me only when I have no other choice at the moment. I usally remove them and effect a proper repair when I can.

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      • #4
        I hate threaded inserts (Helicoil is a brand...like Kleenex), I only use them when the hole is stripped or cross threaded, otherwise they're never used. I couldn't imagine drilling out a perfectly good hole to put a threaded insert in.

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        • #5
          ****, I guess i'm the only one then :P I won't even put a exhaust mani on a turbo car untill the threads have been heli-coiled unless it's a new casting (your "perfectly good hole" then i wouldn't either). But from the years i worked on road race cars (porsche club 944's 928's 911's etc.. ) The rules of the shop i worked in were that we wouldn't assemble a used block without thembeing used on all the exhaust mani and block bolts for the brackets, turbo supports, cooler lines and cooler housings on the block. Half the time the holes in the block after some 5-8 even 10 years of service are so worn out in the threads that you can't even torque half the accessories to spec. before they strip out. Maybe it's just that the cars i've done them on lead very hard lives, running maxed out about 95% of the time and being stripped, inspected and repaired/re-assembled every season

          I've never had a heli-coil strip (and yes i know it's only a brand name) but then again i always torque things correctly and use anti sieze on everything aluminum.

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          • #6
            I can see good use for them especially where repetitious use is required. I too have seen threads in alum give up after a couple times. I like EZ-lok better than helicoil though but in alum I imagine heli's are good, maybe even better as they have less thermal mass of dissimilar materials????

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            • #7
              Originally posted by Sberry View Post
              I can see good use for them especially where repetitious use is required. I too have seen threads in alum give up after a couple times. I like EZ-lok better than helicoil though but in alum I imagine heli's are good, maybe even better as they have less thermal mass of dissimilar materials????
              Yea, i just stick with heli-coil brand because thye've never let me down and are claimed to be stainless steel. PLus i dn't know much about the EZ-lok.. are they made by the company that makes EZ outs?

              OH and helicoils can be taken out if there's issues with their threads.. Take a 90* pick, cut it short on the elbow, stick it down in and use it to back the coil out.. It takes time and patience but it can be done ( i've stuck the wrong ones in before by accident because some of the inserts got mixed up once and i stuck a few standard thread ones in metric holes)

              Fusion king.. I use studs on as much as i can, but i still heli-coil the stud holes If the holese are too thin walled to heli-coil then I would fill them up with AL weld and retap them once they became weak.. I guess there are palces you can't use them feasably, but i use them on as much as i can when i can.
              Last edited by turboglenn; 11-14-2008, 11:22 AM.

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              • #8
                http://www.ezlok.com/

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                • #9
                  If I need to repair threads with an insert before I use a helicoil I would use a Keensert (sp)?. I have had WAY to many Helicoil failures. In the concrete block business that I'm in the molds have to Indore extreme vibrations and stress and helicoils just don't stand up.
                  Bulldog

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                  • #10
                    I guess i have just had good luck with them the whole timei've used them. Aside from getting a hole drilled crooked when i'm in an odd position doing the work, I haven't had hardley any issues with heli-coils. It sounds like some of you use them in much more rigorouse enviroments than i do though.

                    keensert? I'm going to have to google that one. i'm still trying to find the inserts that the japanese motorcycle makers put in their subframes. The tubes are hollow and the inserts look similar to some of the ones on the ez-lok page but none of them that look right are for the application i'm needing. I need something that will slip in a hole in hollow box stock. Even if i have tto tack the edge to keep it from spinning it wouldn't bother me at all. But i havent' found a good insert for hollow aluminum structures yet.
                    Last edited by turboglenn; 11-16-2008, 04:55 PM.

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                    • #11
                      time-sert

                      A Heli-coil is really only advisable for a one-time fixed repair. This means the fastener is basically permanent, as opposed to being removed on a regular basis for maintenance or even future repair. I use time-serts exclusively for all thread repairs. This is Ford's recommendation for spark plug thread repair. There is a special kit for this repair.
                      Ford has had an issue on their Triton motors with the spark plugs blowing out of the head. This is from repeated removal/thread damage/air-tools/over-torque etc..(I think all aluminum threads with a steel fastener face this outcome eventually.) The repair is professional to say the least. They use an undersized threaded bushing that is seated, and pressed in place...virtually eliminating the possibility of the thread coming out when removing the fastener! http://www.timesert.com/

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                      • #12
                        I must admit i love the Time-serts, i've used them a few times back at the porsche shop. The main reason i say heli-coil is because they are the easiest to find and a bit cheaper when you want to do 5-10 holes. like i said on an aluminum head i prefer to do all the exhaust mani holes and then use studs instead of bolts for the final product. Then i use Jet-Loc nuts most of the time to ensure i'm not tightening the turbo mani every 2 track days or so.

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                        • #13
                          Another vote for Timeserts. Many a Porsche case has been improved with them. Just peplacing studs with bigger studs is not that simple in some motors. The studs have to be matched to the rest of the system for even clamping during use. Installing time serts and Racewear studs is part of the improvment plan on Porsche motor cases when used for racing.

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                          • #14
                            Three votes for Timesert.

                            I have done quite a few older HD refits and always used Timeserts for the cases and knock on wood no failures. I have also did a alot of spark plug repairs, customers would bring the heads wondering why no more threads in the head. Gotta love Yuppi mechanics. tight and hot always made me money, and we are not talkin their wifes.

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                            • #15
                              Originally posted by Vicegrip View Post
                              Another vote for Timeserts. Many a Porsche case has been improved with them. Just peplacing studs with bigger studs is not that simple in some motors. The studs have to be matched to the rest of the system for even clamping during use. Installing time serts and Racewear studs is part of the improvment plan on Porsche motor cases when used for racing.
                              The two just go hand in hand. You'd almost htink Porshe owned heli-coil if you didn't know any better. Since having to use them on countless porsche engines, i have just come to want to do complete aluminum castings up with heli-coil/time-serts as soon as they're prepped from the machine shop, i thought i was going to be the only one :P

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