ok i have a problem my friend was driving my car and the drivers side mount bracket bolts broke and the motor fell on the axle which in turn broke the axle sooo. i was wondering who has used heli-coil and would it work on the bolt holes and how you do it i have never personally used it so i need some help. if you know it would be appreciated

 

I was the freind who was driving the car. What happened was about 2 months ago, we were on the highway and noticed a weird noise like a bolt fell off, so we pulled over, and the top bolt broke off. But when we went to put a bolt in for it, it was stripped, so he wanted to get it home so we put the wrong bolt in, but it stayed for 2 months but then it came out this weekend. So now the bolt hole is stripped. We were figuring to helicoil it. And on the bottom bolt on the bracket the head of the bolt broke off so the threads are still in, and they are in hard. But I think we could use an easy out on it or just keep trying to get it out.

 

providing they are put in properly they work fine.

ive had a couple push and pull out.

 

how exactly do you use it? Do you use the stock bolt and just find a helicoil that goes over it and turn it in or what?

 

you get a heli-coil that is the right size for your bolt then you tap out the hole to the heli-coil size and insert the heli-coil and than put the bolt in and tighten it. (you might want to check out Time-Serts and go with them as they are much better) A heli-coil is basically a spring while a time-sert is kinda like a hollow bolt threaded on both sides.


[Modified by SIRX, 3:12 PM 12/18/2002]

 

A lot of race engines use heli-coil type inserts. A typical place you may find them in on the block under the head of a boosted car. A heli-coil is steel and your stock threads are only aluminium. Too much pressure may push the head off the block by ripping the head bolts out of the block.

Even v-8 people use them in iron blocks. The helicoil provides an improved thread surface for bolts to hold onto.

 

so we couldnt use the same size bolts for the holes and just use heli coil for it, we have to retap it anyway? If thats the case we will have to get the bracket drilled a little because i dont know how much room there will be on teh bracket to use a bigger bolt...

 

heli-coil=PITA

 

im an idiot, pita? lol

 

lol...pain in the ***

 

I broke the drivers side mount, Heli coiled it and instead of screwing into it, Igot longer threads and made studs. Studs will be stronger.

 

Studs are not necessarily stronger than bolts. Rather, their 'increased strength' is due to the fact that they are 'easier' on aluminum threads. The big problem with bolts is that when they are torqued, they are galling the threads as well as putting a load on them (due to the turning). But since studs are NEVER turned while under a load, they do not gall the threads. Also, studs are typically bottomed in the hole before a nut is used. This means that they are also grabbing onto more threads than a bolt (which, for practical reasons, does not bottom out in a hole).

 

Helicoils are a valid fix if installed correctly.

What you do is buy a "kit" based on the original bolt size. The kit will include a bunch of coils, the correct drill size, a tap, and an installation tool. Using the correct drill size is critical and they are normally a size that you wouldn't have in the typical drill index.

The coil kind of looks like a little coil spring except it's not made up of round wire. The coils are square in section if you look real close. The edges of the coils are what will be the new thread surface. Both on the inside and also on the outside of the coil.

The hole is drilled out and then taped. The tap provided is a "bottoming tap" and as a result gives threads further down the hole.

The coil is then placed on the inserting tool and screwed into the hole. The inserting tool hooks on a section of the coil. Once installed, a punch is used to break off the "hook". You have to be careful where the hook section goes!

What you end up with is the coil providing the screw surface for the original bolt size. They provide a better anchorage to the block (or what ever) due to the coil providing a larger surface between the coil and the block.


Another thing you may want to think about is what the VW guys refered to as "case savers". These are solid inserts that are threaded on the inside and outside. The case is drilled and taped and then the case saver is installed with loc-tite to prevent it coming loose.

Wes.

 

**** that was a good explanation on heli coil, i think i am capable of doing it, lol. But first i want to take the other bolt out, gonna go right now and try to use an extractor on it and hope i can get it. Then try that later on today or tomorrow.

 

when i bought my d16z6 swap it ahd the tranny mount bolts all broke off, like half gone. so i tip weled it then put heli-coil in all of them an dit worked great. been about 1 year and no prblems with daily driven and beating

 

Cimorelli;

When you go to use the extractor (easy-out), make REAL sure that when twisting on it you are not torquing it off to a side. In other words, make sure the twist is directly in line with the extractor. Apply a SMOOTH amount of force! If you don't do this, it will break!

If you break it, you then will have to use a carbide drill bit to remove it.

Another note about heli-coils; once you start installing the coil, you can't remove it So, make sure that you have taped it the full depth.

By the way, all this is based on "been there, donw that".

If you have any problems, look up my e-mail address and contact me.

Wes.

 

Time-Serts??? Any web sites with info on these?

BillB

 

ok would i be able to weld the bracket on to the block. if so what kind of welder would i have to use arc, mig, etc...?

 

Cant you just shove a longer bolt through and put a nut on the end of it?

 

same ol **** happened to mine...just got a longer bolt and put it in....works just fine...ive had it for awhile now

 

You cant use a longer bolt, seeing how there is only like 1 thread left on the block. Its not stripped where the mount meets the bracket, its stripped where the bracket goes into the block by the 2 14 mm bolts. So we were just seeing if maybe there was a way to weld the mount bracket to the actual motor, rather than keep going through with all these problems. I mean we can take it to a muffler shop and give em 50 and they can weld it, and i am sure the weld would hold pretty good. Anyway any opinions on it? Would it be okay?

 

Cimorelli;

Repair work on items like blocks or heads is kind of a specialized thing. Normally it's not worth having the work done unless it's an item that has already had a lot of costly work done on. Say it's a head that has been ported and all. At that point it's worth spending the money for repair.

I'd recommend that you talk to a couple GOOD machine shops and ask them how they would do the work. I'll tell you what I'd expect you to hear;

Normally the item has to be "pre-heated" in some form of oven. (not your normal kitchen oven!) Then the item (if aluminum) would be welded with a Heliarc welder while still hot. I've seen this done and it's not a fun thing to do due to the heat. If there is a fair amount of area to be filled, as in modifying combustion chambers, then the head may have to go back into the oven several times.

The reason is to keep distortion to a minimum.

In my opinion, this is something that the average machine shop wouldn't have enough experience in doing!!!!!

Wes

 

since it's an engine mount bolt and you have plenty of surrounding material, i'd tape the hole to the next larger size and put a bolt one size larger in it's place.

 

So pretty much the best thing to do is take it to some good shop around town and have them do it right? I guess thats what we will have to do. It was an idea, and we thought there would be some problems with it but. When i tried to get that oen bolt out it broke 3 drill bits in the process, would not go in the bolt, lol.

 

I did a Helicoil on my Tranny casing ... it was not hard at all .... you get the right size you need .... it comes with a drill bit ... this carves bigger grooves into the hole... and the spring looking coil fits into the grooves ... i would put some lock tight thread sealer on the coil .... let it sit in the groove for a bit ... then go back and the bolt is ready to be screwed in .... i would make sure you are ready to put everything back in .. cause you dont want to take the bolt in and out of the coil a whole lot