L322 Oh Dang it - This is a bit more serious - Head off time I think....

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doesnt look like a much manouvering space for a helicoil, no matter what method to stop swarf getting into the chamber i'd be paranoid of something residual getting in and damaging the bores its a feck and half but i would pull the head. helicoiling is going to easier on bench with room rather than risk a bad helicoil in situ. and if it doesnt helicoil then the head is off to get a replacement. and you know that no FOD will happen in the chamber
+1
 
Many thanks for your advice chaps....

As can be seen in this piccie, No. 8 is tucked away under the ABS ECU, and I would be concerned about getting a decent helicoil repair in there. The plugs sit very low inside the head as per the second piccie....

No8.jpg


DSC08594_b673b516-b086-4611-86c2-f7d621c82e22.JPG


@biketeacherdave - No probs, we'll arrange a suitable time - looks like you guys have finished just in time too.....getting a cam 180deg out was a pain!.....Also I don't drink and I wouldn't want anything in any case, it was a pleasure just to be able to help....if you feel you want to do something in return, just bung a few quid in a charity box next time you are passing one....that'll do.
 
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If you were going to helicoil or time-sert it then you would need to drill out the old thread first and then tap it, keeping everything bang on square. My lad broke a spark plug ceramic on his fiesta and that dropped into the cylinder. We tried a small length of pipe on a hoover which got some but we ended up getting the remainder with a bore scope with a blob of grease on the end and guided it towards the debris.
Spiral flute tap would help as would using a generous helping of tapping compound to stick the swarf to it but you would still need to get an angled pistol drill to drill it in situ and some way of guiding it like a nice wooden framed drill Bush bolted in place to the other spark plug bores. I made up some extended clamp bolts that screwed into my spark plug bores by tacking a length of pipe to an old spark plug and then a length of studding in the top.
I have the heads from my project engine on my bench if you want any pics to help Or I could knock something up if you like.
Heads come off easy but quite a long job.
 
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If you were going to helicoil or time-sert it then you would need to drill out the old thread first and then tap it, keeping everything bang on square. My lad broke a spark plug ceramic on his fiesta and that dropped into the cylinder. We tried a small length of pipe on a hoover which got some but we ended up getting the remainder with a bore scope with a blob of grease on the end and guided it towards the debris.
Spiral flute tap would help as would using a generous helping of tapping compound to stick the swarf to it but you would still need to get an angled pistol drill to drill it in situ and some way of guiding it like a nice wooden framed drill Bush bolted in place to the other spark plug bores. I made up some extended clamp bolts that screwed into my spark plug bores by tacking a length of pipe to an old spark plug and then a length of studding in the top.
I have the heads from my project engine on my bench if you want any pics to help Or I could knock something up if you like.
Heads come off easy but quite a long job.
drill guides itself unless your really hamfisted,theres no other cure head on or off
 
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drill guides itself unless your really hamfisted,
Or laying on top of an engine with an extra length drill bit in an angle head drill , with restricted space. A piloted drill will guide itself , a two flute drill opening up an existing bore will go wherever you point it, a 3 or 4 flute core drill is more stable for opening up an existing bore. You can probably buy a combination pilot drill and tap that guides the tool, opens up the bore to the tapping drill size and then threads it in one which will also restrict the swarf falling into the bore.
 
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Or laying on top of an engine with an extra length drill bit in an angle head drill , with restricted space. A piloted drill will guide itself , a two flute drill opening up an existing bore will go wherever you point it, a 3 or 4 flute core drill is more stable for opening up an existing bore. You can probably buy a combination pilot drill and tap that guides the tool, opens up the bore to the tapping drill size and then threads it in one which will also restrict the swarf falling into the bore.
youve got to get enough access as with any job,but std drill that comes with the kit has never needed a guide in the large number of threads ive repaired,your only taking a skim out not trying to drill a stud out
 
Push a decent chunk of cloth into the cylinder to stop swarf & other crap going all over the inside of the cylinder.
Then a Hoover - or Henry - with a tube of suitable diameter taped into the end to suck out the mess.
Can't say I've ever had an issue using a helicoil kit - incl an outboard motor plug.
 
Many thanks guys for your learned advice and experiences - considering No.8 is tucked under the bulkhead, next to the ABS ECU and I can only just get my hand in the space to reach the plug hole.....I think it would be prudent and sensible to remove the head to effect any repair work.

Query for those who have done such.....

Can the head be removed with the exhaust manifold attached or is that foolhardy?
 
Some optimists in the house! Changing valve stem seals with a piece of rope. ..ok. I just don't see this sailing tbh. If it's blown the plug out it may have buggered the hole up anyway. My only experience of swarf in engines has been from folks drilling for lpg nipples on rv8 inlets because they don't fancy removing it......it's normally catastrophic. It's not really a give it a try scenario as you've put the swarf in the bore anyway. Whether or not it works is in the lap of the RR gods!
 
youve got to get enough access as with any job,but std drill that comes with the kit has never needed a guide in the large number of threads ive repaired,your only taking a skim out not trying to drill a stud out
If you have done loads of cylinder 8 spark plug threads on an M62 engine in situ just using an electric drill and your eye then you have done well i would say especially as it’s banked over at 45 degrees and buried in the head
 
If you have done loads of cylinder 8 spark plug threads on an M62 engine in situ just using an electric drill and your eye then you have done well i would say
doesnt matter what engine it is or even what hole has stripped threads,youve got to get access for any job which means stripping back far enough,a guide isnt necessary for helicoiling unlike stud drilling, its a common part of my work
 
Many thanks guys for your learned advice and experiences - considering No.8 is tucked under the bulkhead, next to the ABS ECU and I can only just get my hand in the space to reach the plug hole.....I think it would be prudent and sensible to remove the head to effect any repair work.

Query for those who have done such.....

Can the head be removed with the exhaust manifold attached or is that foolhardy?

I've pulled a few heads off with the exhaust manifold still on. The only real problem is the weight, if you can lift it, it's doable...
 
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