Rover 75 May just be okay after all. Maybe....

[Dave_Q]

Some of these suggestions sound like way more work than fixing it properly.

 

I would have thought you could get access easily enough with a right angle drill attachment thing, (from £7.50 on ebay) although I don't know these heaps well enough to visualise the setup.

 

Aluminium head means it's super easy to both drill and tap, my first ever time using a helicoil kit was to sort out some holes in a cylinder head, I was amazed by how easy it was, although in my case I had a clear run to drill it with no faffing.

[BorniteIdentity]

Some great intel on here, and between everyone it shouldn’t be behind the wit.

 

I’m in the fix it proper camp, only because it does sound just as easy to do it well as to bodge it and scarper.

 

Anyway, stick with it.

[Tamworthbay]

Space is the key, if there is space then a helicoil is a no brainer. The problems start when you can’t get the drill in and that’s where you need to be more creative.

[purplebargeken]

Yes, that is indeed the stud type that is fitted throughout the manifold.There (in my limited world) is bugger all space to be drilling anything meaningful enough to utilise a helicoil type repair setup. 

 

So, are we suggesting that obtaining a few of the bolts should suffice?

[purplebargeken]

I like TWB's slot/weld fix but that is not viable here sadly.

[purplebargeken]

Lots of 8mm x 30mm bolts on eBay, stainless flanged ok? Or......

[purplebargeken]

Umm, whilst being a ham fisted cunt I broke this bit:

 

[Mr_Bo11ox]

Do the wire trick to see how deep the hole is, if it's deep enough for you to get a 5 or even 10mm longer bolt in, and still nip up, it would be worth having that extra length (fnarr fnarr)

[purplebargeken]

Not actual engine ^^

[DodgeRover]

What Mr Billoxs says check the depth in the holes. Can you cut threaded rod to make the best use if the maximum depth available and thread lock it in place?

 

NB an extra 10mm never goes astray.

[Brodders]

I was about to report our results from the day, however Ken has already done so far better than I could. It seems to just be the two bolts that are causing the trouble.

 

I would also like to thank Ken for providing me with my first ever kebab today. I have just finished the re-fried leftovers and it was bloody tasty. Whilst it was fucking frustrating that we weren't able to get it sorted out today, Ken was absolutely great company for the afternoon. Good luck with finishing it off.

[Dave_Q]

Lots of 8mm x 30mm bolts on eBay, stainless flanged ok? Or......

 

Wouldn't use stainless here personally, look for 8.8 grade (bog standard high tensile steel fastener) flanged or hex should be fine.

 

Looking at the stud design it's no surprise the threads get damaged, I can't do a thread strip calculation without knowing the exact grade of alloy the head is made from, but as a rule of thumb threaded holes into aluminium should target (2 x diameter) thread engagement (16mm for M8) so my concern would be that if you get a longer bolt but the undamaged portion of thread is still only 5-10mm it could easily strip again. 

 

Still, deffo worth a pop for the price of some bolts, if you don't mind getting robbed blind for them Halfords do odd bolts like this, they'll just be £3-4 for a bag of 4 when cost price is about £0.02.

[purplebargeken]

The stud depth is indeed utter pants. For the cost of a couple of bolts and a tube of thread lock it is worth a go. If it works then grand, if not well we tried. Plus I now know how to change the IM gasket on a K series lol.

[Tamworthbay]

This is the problem with modern shite, on our fave Dolomites Ken, not only could you fit a drill in you stand next to the engine while you did it. I knew space would be the fecker with this.

[purplebargeken]

Okay, the wire coat hanger remnant of depth sayeth 40mm length/depth in total, from the absolute bottom of the hole to the top which includes the manifold. I bought a smoll pack of HT bolts from Half*rds,some washers and a bottle of threadlock for not a huge amount to be honest. There are two 40mm bolts in the pack. It is impossible to say how deep the thread recess is but I will give it a go tomorrow anyhow. 

 

Wish me luck.

 

Glad you enjoyed your kebab Conor. Kebabs have to happen, it's the law.

[DodgeRover]

Can you run the 40mm bolts down by hand just to check they aren't going to hit the bottom of the hole? I would put a spring washer under each head to be on the safe side. The torque isn't much either.

 

PS I hope you are feeling a little better

[DodgeRover]

 

Looking at the stud design it's no surprise the threads get damaged, I can't do a thread strip calculation without knowing the exact grade of alloy the head is made from, but as a rule of thumb threaded holes into aluminium should target (2 x diameter) thread engagement (16mm for M8) so my concern would be that if you get a longer bolt but the undamaged portion of thread is still only 5-10mm it could easily strip again.

 

Still, deffo worth a pop for the price of some bolts, if you don't mind getting robbed blind for them Halfords do odd bolts like this, they'll just be £3-4 for a bag of 4 when cost price is about £0.02.

I don't understand why they don't make helicoils longer...they all seem less than this rule.

[SiC]

When doing stuff up in an alloy head I tend to use either a nut driver or hold the ratchet end of a ratchet. Then tighten up until it nips tight. Stops me being too tempted to tighten it up too much.

 

If it goes stiff and then loosens, I stop immediately as it's just getting too late. I think what feels slightly loose is much better than too tight with this sort of stuff.

[Dave_Q]

I don't understand why they don't make helicoils longer...they all seem less than this rule.

Not sure on wire type inserts but you can get timesert which is a sleeved insert in longer lengths.

 

With either type though you have gained extra area by going up in diameter, would need my work computer to give actual numbers but your M8 helicoil threads into an M9.something female thread which has considerably more area of engaged thread per length than your M8, obviously the tension on the bolt is still the same as M8 hence why they generally work fine even at approx 1D engagement.

 

I think you can use more than one helicoil in the same hole though if you did want to thread it deeper.

[DodgeRover]

I'm on the look out for a reasonably priced timesert kit for occasional use

[Talbot]

One definite way to fix this is to fit some repair studs.

 

I'd not come across these before until I found them in the exhaust manifold studs of a Type-2 VW flat-4 engine. They have a length of M9 thread one end, and a length of M8 the other end.

 

You use an M9 thread tap in the bolloxed hole in the soft alloy head, with no need to drill out as a stripped M8 hole is perfect as a start for an M9 thread tap. Then wind the M9 end of the repair stud in, and then have a nice M8 stud sticking out for your M8 nut to then hold on whatever it's holding on. Manifold in this case.

 

The only bit that is hardish to find is the M9 three-piece thread-tap set. One of which I now have, so if you do want to go this route, you're welcome to borrow mine. It would post out and back again for pence.

 

The studs look a little like this:

http://www.ebay.co.uk/itm/SPECIAL-M9-M8-Exhaust-Stud-VW-Volkswagen-Porsche-Type4-TIV-914-T25-Late-Bay-Van/380784727764?hash=item58a889d6d4:g:assAAOSwBLlVXcyx

But with a shorter plain bit in the middle. I can't find any on ebay at the moment, but many nut-and-bolt fastener sellers will have them.

[purplebargeken]

Let me try the bolts and see how it goes..... like the idea of the repair stud though.Nifty.

[purplebargeken]

Okay, here goes. Wish me luck.

[Mr_Bo11ox]

those repair studs sound like the perfect solution, nice one

[purplebargeken]

Well, shortest bolt went in the top with a washer and seems to be holding.

[purplebargeken]

and then I drop the fucking thread lock bottle down the recess of the air filter hosing.

 

Cunt

[DodgeRover]

Could have been worse it could have dropped into the crankcase been there got that tshirt...

[tooSavvy]

and then I drop the fucking thread lock bottle down the recess of the air filter hosing.

 

Cunt

All Thumbs, eh?

 

Owning a slick antique Toyota I find little use for my own thumbs*...

 

Could loan out to keep you going ?

 

*however... I once dropped a clutch slave cyl retaining nut into the bell housing of my IMP = you can see it but the flywheel won't let you get it out.. Engine split job

**ah but - magnet tied into long piece of string fed through had it sorted in 10mins

 

TS

[Sigmund Fraud]

When doing stuff up in an alloy head I tend to use either a nut driver or hold the ratchet end of a ratchet. Then tighten up until it nips tight. Stops me being too tempted to tighten it up too much.

 

[SiC]

Yes it's on the list to get a small torque wrench. Mine is only good down to around 40NM. The alloy heads usually seem around 5-15NM max.