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View Full Version : Why do time sert tap sizes seem like a secret?



vpt
06-09-2015, 08:17 AM
I am doing some spark plug hole fixes in some ford V10 trition heads. The "called for" insert is the time sert 51459 which is basically a direct replacement but still incorporates the flaw of only having 4-5 threads to hold the spark plug in which over time fail and blow a plug.

So I searched and searched and found the time sert 44186A which is listed as the same thread size 14x1.25x16.8mm as the 51459 insert but the 44186A is fully threaded from top to bottom. There is a spark plug alternative which I already have which is also threaded all the way and will work in these inserts.

BUT I get the inserts in and much to my disappointment they are smaller OD than the 51459 inserts (which I have the installation kit 5553 for). Now I have already drilled, reamed, and taped one head with the 5553 kit in preparations for the new inserts which now don't fit. So I will be making up new inserts today on the lathe that are fully threaded and will fit the bigger hole in the head.

But I want to drill, ream, and tap the remaining head to the right size of the new 44186A inserts. Here is where I run into the problem, it seems impossible to find the right tap for the OD of the insert. Even the tap I have in the 5553 kit for installing the insert only says 14x1.25 on it (the ID thread for the plug). I can't find any mention or hint of OD tap size anywhere.

Anyone have an idea? I am going to check with a caliper and thread gauge today but most of my day will be wasted making up 5 inserts today.

boslab
06-09-2015, 08:26 AM
Had the same problem with helicoil, lost the tap out of the kit, have no idea what thread it should be, was told that the pitch was the same but it's a special grind to make the tap, they don't sell a tap on it's own, just a kit, it wasn't spark plug in my case it was m8 for a bike engine that had stripped a thread, was in a rush so made a plug m12 with a m8 hole and drilled and tapped for it, not quite a helicoil but it's still going, it was only the exhaust anyway
They do seem to be an enigma, galvanizing taps the same
Mark

JSR
06-09-2015, 08:27 AM
I have a kit by the same people called, I think, "Big Sert". I can't check to make sure because it's on loan to a friend. It uses a very thick wall insert because it is used where the first size insert has failed. Perhaps you have the wrong insert for the kit.

John

vpt
06-09-2015, 08:31 AM
The 5553 kit I have is the (big sert) kit which uses the 51459 insert. But I want to use the 44186a inserts which are fully threaded but when I got them I found out they are thinner and have a smaller OD than the kits 51459 inserts.

bborr01
06-09-2015, 09:21 AM
They don't use a standard thread. They use a proprietary thread that is likely only used for inserts. You need to buy their tap or make your own.

Brian

tjs
06-09-2015, 09:31 AM
I have the triton time sert kit and did this a few years ago. I have to check now, however I think I have full plug engagement and have had no issues in years. Knock on wood. I made my money back by doing 2 other trucks for people.

ed_h
06-09-2015, 11:24 AM
Try Googling "STI taps". STI = Screw Thread Insert.

Ed

Toolguy
06-09-2015, 12:16 PM
The STI taps are for Heli-Coil and other coiled inserts. The size shown on them is for the internal size of the insert. The tap is much larger than marked because it taps the hole for the outside of the insert. These taps don't work for anything else as far as I know.

I don't like the coiled inserts because I have had a lot of them pull out or unscrew. I much prefer the KeenSert brand or Keyed Insert generic copies. These are a solid insert that are threaded inside and outside with solid material between the threads. They have drive keys so once they are installed the keys are driven into the threads and then they will not turn, either in or out.

They will not pull out like the others which are just a diamond shaped wire formed into a helix. The outside threads on Keenserts are a standard size tap with a different thread than the inside. Thus, a standard set of taps is all that is needed to install them. If one strips out, it is the easiest thing in the world to replace. You simply drill out the middle, bend the keys inward, screw out and replace with a new one.

They come in thin wall, medium and heavy duty, regular and stainless steel, inch and metric. They even have blank ones so you can make your own internal thread size or move a hole location. The tap and drill sizes are easy to find from many sources. The KeenSerts take a bigger tap drill than normal, but use standard taps.

LKeithR
06-09-2015, 12:38 PM
...I much prefer the KeenSert brand or Keyed Insert generic copies...

Yeah, they've been my favourites for a long time. A bit pricey but they work. Helicoil has advertised their way to being the most "popular" thread repair insert, and, to be fair, for a lot of situations they're all you need, but they're just not as good as a keyed insert...

Doozer
06-09-2015, 02:47 PM
For what it is worth...
I have never had a Helicoil spring come out.
I have had numerous keensert, or other inserts come out
with the bolt, these not installed my me, so perhaps dubious methods
were used. I think timeserts use the same pitch thread as the origional
thread, just like Helicoils, but I don't know if they use Helicoil STI taps
or their own variant.
Not 100% sure, but I do not believe 14mm spark plug threads are
the same pitch diameter as regular 14mm bolt threads. The pitch
might be the same, but not the pitch diameter. So I don't think you
can successfully substitute bolt inserts for spark plug inserts.

-Doozer

Willy
06-09-2015, 05:06 PM
...............

Not 100% sure, but I do not believe 14mm spark plug threads are
the same pitch diameter as regular 14mm bolt threads. The pitch
might be the same, but not the pitch diameter. So I don't think you
can successfully substitute bolt inserts for spark plug inserts.

-Doozer

I believe Doozer is right. Don't quote me on this until I've had time to verify it but I think the pitch diameter for a 14mm x 1.25 plug is about .008"-.009" smaller. I realize of course different tolerance taps can be purchased but I at least don't have any close enough in my standard 14mm x 1.25 taps to warrant trying. I do however have a a set of Snap-On spark plug taps that work much better. I'm thinking that the SAE wanted to distance themselves from the ANSI on this one for some reason.

CarlByrns
06-09-2015, 05:18 PM
I much prefer the KeenSert brand or Keyed Insert generic copies. These are a solid insert that are threaded inside and outside with solid material between the threads. They have drive keys so once they are installed the keys are driven into the threads and then they will not turn, either in or out.


That's essentially what a Timesert is, but instead of drive keys, the installing tool swages the insert in place. They're ideal for holes that would be inaccessible any other way (Honda head bolts, for example- very deep in the block). The 'time' in Timesert refers to the inner and outer threads being synchronized so the wall thickness is uniform. They are expensive, but you get what you pay for.

vpt
06-09-2015, 09:09 PM
I checked the inserts today and the OD thread was still 1.25 like the internal and the best I could figure is the OD thread size for the 14x1.25 insert is a 16x1.25 tap.

But since I got the lathe all set up and turning inserts to fix the holes I already went over size with I figured why not just make up 5 more and match the other head.

http://i.imgur.com/qpPTvaU.jpg

http://i.imgur.com/Cel8V9Y.jpg

http://i.imgur.com/SfEG2au.jpg

Here you can see the factory insert on the left. Much like the head it only has 5 threads at the bottom (head has 4). The center insert is the 44186a (too thin) insert. And the one on the right is the one I made, fully threaded and the right size for the install kit/tap.
http://i.imgur.com/CS4uDsY.jpg

Toolguy
06-09-2015, 09:14 PM
Nice job Andy! I bet those will work great.:)

Doozer
06-09-2015, 09:33 PM
I have turned out some great parts on my old
shltty Atlas lathe. Almost afraid to admit it.
I see your photos are cropped tight, but you
can't fool me.

-D

vpt
06-10-2015, 10:28 PM
I have turned out some great parts on my old
shltty Atlas lathe. Almost afraid to admit it.
I see your photos are cropped tight, but you
can't fool me.

-D


haha

Even though it flops around like a noodle I like my atlas! I have tooled it up quite well and it does everything I need. I just wish I had some extra throw at times.

oldtiffie
06-10-2015, 11:40 PM
http://en.wikipedia.org/wiki/Threaded_insert

https://www.google.com.au/?gws_rd=ssl#q=helicoil+insert

John Garner
06-11-2015, 12:37 AM
Standard TimeSert thread repair inserts are designed to screw into the same-size tapped hole that the same-size-INTERNAL-thread standard wound-wire insert fits. Or, to put it another way, the hole to be threaded for either a standard TimeSert or standard wound-wire insert should be very nearly the Major Diameter of the screw that fits into the insert, and the Major Diameter of the tap should be approximately One Pitch of the screw that fits into the insert larger than the Major Diameter of that screw.

BUT there are "special thick-wall" TimeSerts and "oversize and double oversize" wound-wire inserts (Heli-Coil calls 'em Oversize and Twin-Sert inserts) with non-standard ODs that have their own rules of thumb.

As I've said many times here and on other bulletin boards, I prefer the EZ-Lok adhesively-retained solid inserts generally, but for those applications where the best on the market may be good enough . . . Lock-N-Stitch's Full-Torque thread repair inserts are about as good as it gets.

http://www.timesert.com/

http://www.stanleyengineeredfastening.com/brands/heli-coil/screw-thread-inserts/types/oversize-twinsert

http://www.ezlok.com/inserts-for-metal

http://www.locknstitch.com/sparkpluginserts.htm

John

thaiguzzi
06-11-2015, 12:51 AM
Excuse the pun - this is a good thread... My Timesert kits for 14mm spark plug repairs have a std 16 odd mm o.d, the Big Sert as previously mentioned is mainly aimed at previously repaired plug holes and has a whopping 18 odd mm od. Certain applications this is getting close to valve seats and affecting chamber displacement. Probably no probs in a big 'Merican V8 etc. In Spark plug thread repairs i also prefer the solid insert type over wire helicoils.

thaiguzzi
06-11-2015, 12:51 AM
Forgot to add; very nice work on the replacement inserts.
Mike.

vpt
06-11-2015, 08:34 AM
Standard TimeSert thread repair inserts are designed to screw into the same-size tapped hole that the same-size-INTERNAL-thread standard wound-wire insert fits. Or, to put it another way, the hole to be threaded for either a standard TimeSert or standard wound-wire insert should be very nearly the Major Diameter of the screw that fits into the insert, and the Major Diameter of the tap should be approximately One Pitch of the screw that fits into the insert larger than the Major Diameter of that screw.

BUT there are "special thick-wall" TimeSerts and "oversize and double oversize" wound-wire inserts (Heli-Coil calls 'em Oversize and Twin-Sert inserts) with non-standard ODs that have their own rules of thumb.

As I've said many times here and on other bulletin boards, I prefer the EZ-Lok adhesively-retained solid inserts generally, but for those applications where the best on the market may be good enough . . . Lock-N-Stitch's Full-Torque thread repair inserts are about as good as it gets.

http://www.timesert.com/

http://www.stanleyengineeredfastening.com/brands/heli-coil/screw-thread-inserts/types/oversize-twinsert

http://www.ezlok.com/inserts-for-metal

http://www.locknstitch.com/sparkpluginserts.htm

John

Yes the thinner and wire inserts are the same pitch as the ID screw/spark plug. I found the thicker inserts I made (matched the original) had an OD pitch of 1.5 while having an ID pitch of 1.25.




Excuse the pun - this is a good thread... My Timesert kits for 14mm spark plug repairs have a std 16 odd mm o.d, the Big Sert as previously mentioned is mainly aimed at previously repaired plug holes and has a whopping 18 odd mm od. Certain applications this is getting close to valve seats and affecting chamber displacement. Probably no probs in a big 'Merican V8 etc. In Spark plug thread repairs i also prefer the solid insert type over wire helicoils.

Yes I went with the "triple over size" inserts right off the bat. It is known that the thinner inserts fail (reason bigger ones are made) in many ways. They uncoil, or crack, or are easily pulled out with the plug. These thicker inserts have the ID thread only ran about 7/8 of the way down. After they are put in place in the head a driver tool is ran down them to cold form the rest of the ID thread and expand the insert in the hole to "lock" it in place. I also applied copious amounts of anaerobic loc tite. lol

Here you can see one insert in and one hole prepped for an insert. The hole is drilled and reamed out to be quite large for these inserts. Still plenty of room before valves get involved but I was a bit worried when running the driver tool down that the expanding insert could possibly crack the material between the hole and a valve seat.

http://i.imgur.com/6kCtr5d.jpg

Spark plug in.

http://i.imgur.com/Q2cbfHK.jpg

If this is done with the head on the motor yet a guy has to make sure the valves are shut and the piston is way down out of the way. This is the reamer bottomed out.
http://i.imgur.com/L1kwQZJ.jpg

Heads are back on!
http://i.imgur.com/XxQVANv.jpg

Doozer
06-15-2015, 08:57 AM
Andy-
Are you cutting metric threads on your Atlas lathe?
If so, A+++!

-Doozer