Disaster

take the head off, either heli coil or weld and re tap.

Welding is the better option imo. also its not expensive, 20 buks maybe. Then tap it your self if you're confident or get them to do it while you are it.

oh and best to find someone that can and does weld heads in particular magnesium alloys. If they don't have much experience doing this kind of work, fine someone that can or heli coil if you can't.

u don't need to take the head off
it can be Time sert repaired in sit_u
❗❗❗❗
The previous posters advise is Crazy

Brian wrote:u don't need to take the head off
it can be Time sert repaired in sit_u

I have had this done to my car

Timesert is the way to go 👍

Hi

Helicoil as a last resort, Timeserts are way superior. If its # 1 or 3 you can do it in the car. I've seem too many Helicoils unscrew with the plug.

Steve

timeserts..hmm interesting. never seen them before? Still you can to take the head off otherwise bits of metal shavings will get in the cylinder.

not if its done by a skilled person

Brian wrote:not if its done by a skilled person

As we know, the VW engine bay is far from mechanic friendly when it comes to repairs on the heads except a few things.

If you note the sequence of inserting a timesert, which is designed for hand fitting, not machine, it requires things to be still square to the sealing face of the plug hole.

From L to R

(a) Clean hole with drill provided.

(b) Counterbore hole for insert top flange

(c) Tap hole

(d) Screw in insert with threadflow tap/installation tool. This squeezes the bottom of the insert out into the wall of the tapped hole as the last couple of threads aren't fully formed.

Now, my thoughts on this is that no matter how skilled we are, there's a chance of getting out of square as well as dropping some shavings inside the combustion chamber when working inside the engine bay. At least the top tinware and the inlet manifold has to come off to give some sort of a professional repair using timeserts in this situation.

Another problem with Timeserts in cramped situations is that the tap supplied is barely an intermediate which makes it difficult to start square. Note: The ones shown are from a standard kit, not a sparkplug kit. see http://www.timesert.com/html/sparkplug.html

The helicoil tap in a plug repair kit can have a pilot which is the original size thread to keep things square before the new size thread is tapped. You still have the danger of dropping the small tang into the combustion chamber when removing it from a Helicoil and of course it is stainless steel, not alloy!. In any case, a grease type of cutting lubricant in the flutes may trap most of the shavings preventing them dropping into the combustion chamber.

As for welding and re tapping, there's more to it than a splatter of weld and re-tapping. The hole has to re-drilled in the right place and then spotfaced and tapped which really means to do it correctly a milling machine is required................for 20 bucks??? I don't think so.

And lastly, I would think 2 or 4 would be easier to get to than 1 or 3 ❗

DH

vernier68 wrote:hi, timeserts seem the way ahead, but as you say, keeping it all square would be a task. Ideal repair if the head was off.
unusual to see a drill with a square tang in the kit unless you drill it by hand with a ratchet tap wrench.
The original hole would act a a rough guide when drilling, but the tap is close on a plug or bottom tap.
i personally dont like helicoils, never used em on submarines.
Swarf can be an issue, load the flutes with some grease perhaps.
safest way is head off, timesert i think.
Welding and machining the head would be expensive, safer just buying a new head.
malc

Ex Navy or ADI???

Helicoils are a problem if:

(a) Plugs not sealing allowing carbon to track along the thread.

(b) Plugs not changed at normal intervals.

(c) Plug reach too long which allows carbon to build up on the last thread of the plug.

Any one of these user faults can pull a helicoil insert or in fact most inserts out of a head.

Remember Timeserts can't be cut to a shorter length otherwise the locking feature will be lost. If they are shortened, the driver can't fix them against the top flange tightly and the only way to lock them in is to stake the bottom with a punch. Each insert type can have a problem.

In any case, doing the repair with the head on can only be treated as a temporary fix as you can't see where the end of the insert is.

DH

1500S wrote:And lastly, I would think 2 or 4 would be easier to get to than 1 or 3 ❗

DH

Hi

When I worked in VW shop the owner of the shop fitted many Timeserts with the motor in place, 1 & 3 are easier because there is more room as body tapers down around 2 & 4, talking about Beetles in this case.

Type 4 motors were a pain as the plug thread runs across a valve face. It saved a people a lot of grief, imagine having your car booked in for a routine service and then being faced with the cost of having to have partial engine tear down or worse.

All care was taken to keep shavings out of the combustion chamber but anything left over would blown out when the motor ran, we made valve adjustments before the insert was done and the motor set on TDC. It was treated as a temporary repair but we never had any come back and most cars need new heads after a while anyway.

Timesert also made repair kits for Solex carbs which were very useful when the heavy idle jets on Type 3 and Twin carb Kombis flogged out the idle jet hole.

Steve

I know that these fixes can be done and are done Steve but I can't help looking at things "the proper engineering way". Of course a customer wouldn't be happy with a bill for a partial rebuild when all they wanted was a plug changed. I know if I had the problem myself the engine would be out to do the job but in many cases with old VWs these days if the owner can't do most of the repairs themselves they wouldn't have a clue as to whether the job was done right or not. Somewhere down the track the engine will have some other problem and indeed new heads will be recommended so the old rough repair wouldn't be seen by the owner. In the end, use whatever insert is the favourite choice but in the long run they all work well if used as they were designed.

Yes, I do know that Timesert states that the repair is done without the removal of the head but I just don't like bits of metal floating around in the combustion chamber regardless of how many strokes it doesn't take to clear it. 🙅

The proper sparkplug Timesert taps are similar to the Helicoil ones by having the original plug thread pilot. The ones I posted in the previous post are the standard inserts from the general engineering kit.

For ref.:

http://www.timesert.com/html/sparkplug.html

A bit of an expensive outlay for home uses unless you plan on doing plenty of heads!

Just looking at it, what car would use a 1/4"-32 thread. 😂

DH

Maybe a model engine like used in radio controled cars boats and planes, maybe

donn wrote:Maybe a model engine like used in radio controled cars boats and planes, maybe

Yep! Off topic a bit but 1/4" UNEF. Couldn't get the timeserts when I needed some so went with another lifetime of Helicoils. Haven't got the problem with carbon buildup using methanol/nitro methane/castor oil so never have the problem of them coming out !!

DH

Just checked back over all my posts and then checked with the misses, have proved my suspicion that this is the first time I have ever been correct. 😂 Just a question off topic, if a fella says something while his wife is outa hearing range, is he still wrong. Just wonderin. 🙅

donn wrote:Just checked back over all my posts and then checked with the misses, have proved my suspicion that this is the first time I have ever been correct. 😂 Just a question off topic, if a fella says something while his wife is outa hearing range, is he still wrong. Just wonderin. 🙅

Always work on the principle of "not very often I'm wrong but I'm right again. I thought I was wrong once but it was just an error of judgement" 😂

DH

what method was he planing to use?

really? that much to do a heli coil. lol my local engineer welded, re cut and taped a ford laser thread for 75 I think. was a few years ago.

That engineer is great. 10 buks per weld for heads.

I can get a ford e series head welded and machined between 70-100 buks.

And great job too. I get them machined by another guy in town though. 55 per machining.

He has a machine shop in his mechanic bussiess 😁

Helicoils are actually scarily expensive, as I found out last time I needed one. The helicoil 'kit' including the tap was something like $60 for a small one to do a sump plate bolt, so I can easily imagine spark plug ones being $80.

If you want to setup your kits while the A$ is good then get http://cgi.ebay.com/ebaymotors/TIME-SERT-NEW-Spark-Plug-Kit-M14X1-25-Part-4412-_W0QQcmdZViewItemQQhashZitem3eff8a65edQQitemZ270575232493QQptZMotorsQ5fAutomotiveQ5fTools.

No inserts but this is the expensive part of the tool kit. For 10 inserts they want around 30 bucks plus postage.

With this in mind, no one should gripe at what an engineering place charges for doing what seems a small job! Quite an investment to have sitting on the shelf with an assortment of insert lengths to suit a number of vehicles.

DH

Looks like the tap isn't of great quality although it may be just the poor quality photo! Remember that the Time-sert design of insert requires a small counterbore for the head of the insert and also requires the tool to insert it as well as set it into position by forming the last couple of threads on the insert which actually locks it into position. Using a poor quality imitation may give more problems down the not too distant track. I know that others on here don't like helicoils (Recoil) but I've had them in engines since the 60s without any problems. My current engine has Helicoils in from rebuild 9 years back and certainly hasn't given any problems.

DH

I actually prefer Helicoil over a Timesert, they don't require as large a hole in the head, and you can shorten the coil and make a tool to deform the threads so the coil doesn't back out.

As Matt said, the Helicoil insert should be at least 1/2 a thread below the surfaces. If a suitable punch is made to deform the alloy near where each end of the insert is the insert cannot screw any further in and can't back out.

Helicoil engineers say that this is actually not necessary and may damage the parent metal, however in the case of the VW head it should be ok.

" Free Running Inserts Helicoil
In the free state HeliCoil Inserts are greater in diameter than the tapped hole into which they are installed. In the assembly operation the torque applied to the HeliCoil tang reduces the diameter of the leading coil and permits it to enter the tapped thread. When the torque or rotation is stopped, the HeliCoil coils expand with a spring-like action anchoring the HeliCoil insert permanently in place against the tapped hole. No staking, locking, swaging, keying, nor interference fit is required to retain HeliCoil Inserts, thereby eliminating stress concentration in the parent material. The HeliCoil Insert automatically adjusts itself, radially and axially, to any expansion or contraction of the parent material."

DH

Yeah Dallas, I actually grind a taper into an old plug and use it to crimp the top thread.

I thought I'd add that bit from Helicoil Matt. Too many non engineers on some forums have odd expert thoughts on some of these fixes. Even though I have a full Timesert kit from M4 to M12, I'm not about to spend $150 plus to get the ones for the plugs. The Helicoils have worked as designed for all these years so why change!

DH

Helicoils are Not suitable for alloy spark plug threads IMO

Matt ....The time sert uses the same size tap as the helicoil (almost) in fact the helicoil tap is slightly larger
I have fitted Time serts in the thread cut for a coil as a temp solution.
You can easily start em square as they have a std 14 thread on the end as a lead ❗
Also a face cutter is used to ensure the sealing surface is square with the new thread.
Often if you tighten up a plug that has a Heli -coil fitted the coil pops straight out . 😀

DH

that time sert you have shown is NOT the spark plug M14
I have never had to Drill the head to fit a time-sert (I have fitted dozens of them )

In fact they don't recommend or even supply a drill in the kit
So your fitting procedure and advise is plainly wrong 😵

johny rotten wrote:Helicoils are Not suitable for alloy spark plug threads IMO

Matt ....The time sert uses the same size tap as the helicoil (almost) in fact the helicoil tap is slightly larger
I have fitted Time serts in the thread cut for a coil as a temp solution.
You can easily start em square as they have a std 14 thread on the end as a lead ❗
Also a face cutter is used to ensure the sealing surface is square with the new thread.
Often if you tighten up a plug that has a Heli -coil fitted the coil pops straight out . 😀

I thought I made myself quite clear that the ones I had in the pic were a standard set, not a spark pug repair. See again.

I never go by IMO but by manufacturer's recommendations and Helicoil/Recoil inserts are recommended and widely used in the repair of alloy heads The insert cannot pop out when the plug is tightened. With Timeserts, there isn't a face cutter to make sure that the thread is square with the face. That is achieved with the use of the correct stepped tap, ie M14 x 1.25 stepped to Timesert thread.

DH

DH
you are quoting manufactures spec on a time sert that is NOT the one in question
very misleading

Also the timesert M14 spark plug repair DOES have a facing cutter I have one in my tool box
So before you go giving false and misleading advise to the kiddies on these pages
Check your facts

any one who fits a helicoil to a vw air cooled head is mad IMO

its obviously pointless trying to explain this to some 😵

I'm hearing ya Johny...

I thought that timeserts did have a face cutter, mine was purchased from Wurth in '94, but haven't used it in years since I honestly had more drama's than with Helicoil's fitted with the crimped thread method.

We'll have to just agree to disagree.

Why in your opinion is the Helicoil so bad for alloy heads?

johny rotten wrote:DH
you are quoting manufactures spec on a time sert that is NOT the one in question
very misleading

Also the timesert M14 spark plug repair DOES have a facing cutter I have one in my tool box
So before you go giving false and misleading advise to the kiddies on these pages
Check your facts

any one who fits a helicoil to a vw air cooled head is mad IMO

its obviously pointless trying to explain this to some 😵

The Timesert I am refering to is http://www.timesert.com/html/sparkplug.html

It has:

(a) Stepped Tap

(b) Wrench

(c) Seat Cutter

(d) Insert Tool

The seat cutter cuts a small counterbore for the flange on the insert top to clear the contact face, not to square anything to the thread if the tap goes in out of square.

With this in mind I am not giving the kiddies or anyone else on the forum misinformation. I did explain back somewhere that thie pics were from a standard kit, the difference being it has a drill for cleaning out the hole and a standard type tap rather than the stepped one. Also, the standard Metric Coarse and Fine series of Timeserts doesn't hafe the M14 x 1.25 thread size. That one is great for stripped threads in places like our oil strainer studs. Standard helicoils aren't much good in that aplication.

Now Johnny ol' boy, as you have a Timesert tap for sparkplugs in your kit, can you measure the effective diameter of the tap so we can compare with Helicoil tap for size. For reference, the effective diameter of the M14 x 1.25 Helicoil tap measures 15.00mm.

Yes, sometimes it is hard explaining concepts to people. 😂

DH

Edit to remove useless photo

The seat cutter cuts a small counterbore for the flange on the insert top to clear the contact face, not to square anything to the thread

DH [/quote]



Wrong again
as I have already said THE SPARK PLUG SEAT CUTTER also cuts a face cut to seat the plug on , square to the hole .
Why show a pic of a cutter thats not related to spark plug repairs except that it is the same brand ??
now what part don't u understand

johny rotten wrote:The seat cutter cuts a small counterbore for the flange on the insert top to clear the contact face, not to square anything to the thread

DH

Wrong again
as I have already said THE SPARK PLUG SEAT CUTTER also cuts a face cut to seat the plug on , square to the hole .
Why show a pic of a cutter thats not related to spark plug repairs except that it is the same brand ??
now what part don't u understand [/quote]

With this forum it's about helping one another. It would be simpler if we could all put a pic on to show what things do rather than just "wrong" with nothing getting clearer! After having a look at a sparkplug kit I sourced today, where the standard one has only the cutting edges for the counterbore and the larger diameter is squared off to give a depth stop for the insert flange, the plug one indeed has cutting edges to scrape a new seat for the washer face just to make sure. I've had time to look at the Timesert site so here it is for all to see.

See: http://www.timesert.com/html/howtosp.html

That pic from the ones who have a kit could have saved this long winded back and forth!

NOW! What is the efective diameter of the Timesert thread so we can compare it with the Helicoil tap?

and

What is the answer to Matt re the reason why Helicoils should never be used on aircooled engines remembering that Matt is a long time VW motor mechanic.

And now at least vlad01 can see what a Time-sert is. 😂

DH

Really
you had time to post all this false info ,

The pics you found time to post were also useless 🤪

as I already told you the tap from the Time sert is a tad smaller than the helicoil one

I can give you a measurement later

How many spark plug repairs have you DH done personally ❓

I am speaking from direct experience

Helicoils can hang through into the combustion chamber, they are not finished square at the ends ❗
they some times leak ,
they often come out with the plug and wreck the head
they promote cracking
They are easy to stuff up during install as there is no step on the tap to use as a lead

But they do seem OK in cast steel

Beware of the K and D inserts if thats what they are ??

even worse than helicoils

K and D inserts were common place in the VW repair industry 25 years back , I was hoping they were gone forever ..

I just checked his web page and they are the old type 🤪
I would not use em
find some one with a time sert
what area are u in ?

The plug will tighten up on the insert rather than the head , this will cause the insert to "stick" to the plug (this is a bad thing)
also the thread on the OD is a nasty one rendering your cylinder useless in a very short time
there must be someone with a timesert repair kit near to you .

johny rotten wrote:Helicoils can hang through into the combustion chamber, they are not finished square at the ends ❗
they some times leak ,
they often come out with the plug and wreck the head
they promote cracking
They are easy to stuff up during install as there is no step on the tap to use as a lead

But they do seem OK in cast steel

Ok Johnny nice guy, look at your comments

Helicoils can hang through into the combustion chamber; Only if the installer fits the wrong length Helicoil

they are not finished square at the ends : Obviously, but If care is taken when installing a plug by starting by hand, this is a small price to pay

they some times leak : The plug washer is meant to do the sealing against the head, same with a Timesert

they often come out with the plug and wreck the head: If the thread gets crimped like Dallas and I suggested this is less likely with a Helicoil than a Timesert IMO, but none the less it's an issue with any of these repairs, but it is just that, a repair that is relatively cheap to get back on the road, noone said it's as good as a new head

they promote cracking : WTF there is no difference in the amount of material retained on your own admission

They are easy to stuff up during install as there is no step on the tap to use as a lead : And we're back to installer f*ck up...not the insert.



Show us your version of insert, the ones in the pic from George look like what I'd call a Timesert, but I'm happy to learn.



For the record, I'm on the Sunshine Coast, albeit close to an hour away from Coloundra, I have Helicoil's of different lengths in stock, I can often do the repair in car for under $100. 🙂

Hey Matt

If you can't see any issues with helicoils go right ahead and fit em

I'll continue to do what I think is best and fit time-serts

I won't be adding any photos
😉

I've had more issues with the large style insert wrecking heads than helicoils, so I'll continue to use Helicoils untill I see a better option. If you don't wish to share your obvious welth of info, why bother with this forum.....

I for one would be happy to see the 'correct' insert your recommending.

Have a nice day. 🙂

Hi Matt. Back again after a few days away. Hope Malc has by now got that head fixed and back running. Time wise and cost wise it would have been better to drop in to you to have the insert fitted!

To answer a couple of Johny’s questions and for the history:

Yes, I have repaired quite a few Volkswagen heads. With owning VWs only from 1965 to 1979 as main transport with two Type 3s and continuing with one to 1984 there were a number of my own rebuilds and repairs coupled with work colleagues and mates along the way. Thread inserts in general? Thousands as It has been part of the last 30 years demonstrating the fitting and uses of them! It helps to have been in engineering for near 50 years as a Fitter/Machinist/Toolmaker. You don't have to rely on other trades to wreck your equipment These were mainly Helicoils although there were some inserts of thicker walls than timeserts which did decrease the head strength around the plug hole due to the larger tapped hole. That one was staked or swaged to keep them in.

Now, on looking back, I can’t find where I gave misleading info except that I used the standard set of Time-serts to show someone what they looked like with a bold note regarding the fact they were not the Plug set. I hadn’t come across the specific Time-sert plug kit but a pic showing the difference with the integral seat/counterbore cutter would have cleared that up. Yes, I do have some time to post photos. Pictures do speak for themselves and explain much more than just text. It’s a pity a few more wouldn’t do the same!

FACTS.

As there has been no reply on the measured difference between the Time-sert tap and Helicoil tap may I add that first.

S.T.I Basic P.D. = Nominal Thread O.D (Basic Major Dia.) - Basic P.D. + Basic Major Dia. Note: This is info from Time-sert, not some idea I have invented.

So in the case of the STI M14 x 1.25 , STI Basic PD = 14 – 13.188 + 14 = 14.812mm

Comparing this to a Helicoil tap which is measured at 15.00mm, the difference is 0.188mm smaller.

Where does all this lead?

V-threads have a self locking feature just by the design nature of the animal. It is due to the bursting influence the v has between the male and female thread. As we know well, the air-cooled VW heads are widely known to crack from the plug hole out to the ports. Just by tightening the plug too much puts a radial load on the hole which can open up the crack a bit more causing a leak in that area.

Time-sert v Helicoil:

The Time-sert is designed with an underformed female thread so when the installation “Threadflo” tap is used, it both drives the insert as well as forcing the insert hard against the tapped hole to lock it in place as well as complete the forming of the female thread to the standard size.

Now, by using a Time-sert in place of a Helicoil “because we all seem to be idiots by using Helicoils” you are most likely inducing a crack just as much as you think a Helicoil will, especially if the hole already has cracks starting due to the high radial load placed on the hole. Also, by your own admission, you used a Helicoil tap rather than the Time-sert one knowing that the Helicoil one was slightly larger thus creating a looser fit of the insert which could result in early failure again by having the insert come loose.

In light of this, I don’t think myself or Matt has given any misleading info on the subject. It has been an enjoyable time here on Aussieveedubbers with making bits for Dubbers all over the country as well as loaning them tools etc. However, there is only a certain amount of crapp one can put up with from a minority so I feel it’s now time to crank up the old 1500S and drive away from the scene.

DH

😀

All good Dallas
Cranky Johnny (who ever he is) often likes to make point blank statements with questionably unsubstantiated do or die cold hard FACTS that we mere mortals only dream to understand.

Why would I use a Helicoil Tap !!

I don't even own one


I said that I have fitted Time serts to threads cut with a helicoil tap .
I did not say that I tapped the hole using a H- coil tap

Hey Matt

I stated my opinion only



you don't have to like it 😎

lighten up

All cool this end, I was just wanting to see your version.

Thanks Mat
Although I have 150K in tools , I don't own a camera
but in the last week or 2 I have been thinking of buying one 😊

I have used helicoil, spark fitted inserts and Timesert and my vote is for the Timesert, its worked for me.