broken thread 3b intake manifold injector inserts

[Lopez90]

I bought a set of alu injector inserts for my 3b.

1 of the inserts got stuck while screwing in and it would go in or out, so i had to use force wich resultet in broken threads on the intake manifold. Had to cut insert to get it out.
Any suggestions to fix this?

[Lopez90]

edit: pictures

[Tractor Dave]

I would take it to a good machine shop to get a timesert fitted.
The cheaper option is to run a thread cleaner down it then use temp resistant thread lock when you fit your insert.

[K Simmonds]

As Dave say's the text book repair woud be to get Timeset or the like fitted...

However as it's a thread you probably only intend on using once and there not being a great deal of surrounding material I'd carfully clean the thread with a tap then tidy up the seat area at the base of the hole to ensure a good fit of the alloy injector insert and fit with it with pleanty of heat proof thread lock. Any excess can be cleaned off after your happy the insert is home.

To be honest even this I would give to a machine shop to do as they have the correct type of tap and will clamp the manifold down and use a drill press to start the tap off dead square. It's one of those jobs you only want to do once and do right.

Edit... If I was doing it at home then I'd want the manifold in vice so it's held firm whilst you start the tap, you could also use some heat resistant PTFE tape on the threads of the new insert.

[Laaf]

If memory serves me right I also used a thin bead of silicone sealant on the sealing surface at the bottom of the injector inserts as they where giving me smalll boost leaks otherwise.

[newsh]

Yes with the correct tap and some hi temp silicon sealant that will be fine.

[Lopez90]

Will be running 4 alu inserts and 1 orginal plastic for now, since one broke and they were a bit expensive from poland.
One of the local car mechanic shops tried to rethread it, but failed. Might take this one out of town to get a proper shop to look at it.

Bought a new intake for a very good price so i can continue with the car for now

[K Simmonds]

Well, I'm glad you've picked up a cheap replament manifold to keep you on the road.

As I mentioned just retapping the OE thread will be a little tricky... To do the job I'd want two taps of the correct thread, one tappered and one with a pretty much flat nose. The manifold must be secured and it wouldn't take most machine shops long to get it clamped down to an adustable datum surface.

At work I'd probably use the mill as that's the best machine we have for the job, it would take me half an hour or so to get it clamped up and the chuck at 90 degrees to the hole. I'd use that to manually start the tappered tap off square then recut as much thread as I could with that before swapping to the flat nose tap to do the final cut.

It's actually quite a fiddly job.

[Lopez90]

My «new» intake had a stuck insert aswell, but thankfully it was plastic so i manage to split it without any damage to the intake.

Running 4 alu and 1 plastic now, with o-rings. Hopefully it will seal better.

Anyone got torque setting on intake? If there is a fully list of torque settings on the car i would be very happy if anyone shared :-)