MagicalArmchair
Well-Known Member
Thanks Richard, will do... I'll report back on how the stud extraction process goes...
Gads, disaster! 2GM20 exhaust elbow bolt sheered off!
- Thread starter MagicalArmchair
- Start date
Hydrozoan
Well-Known Member
Jus' jokin' - I'm sure Pete's Blu-tack sticks better than Plasticine (my thanks to him, too)
. Still dunno if either makes a jot of difference ... but costs next to nowt. I didn't like to mention greasing the new ones at this moment but since you've mentioned it ...
rob2
Well-Known Member
I wish you joy with trying to extract the remains of the bolt! I suspect that as it resisted to the point of snapping, it may not come and will have to be drilled out. Even if that doesn't go quite to plan, there are two further options for a repair. First is simply to drill out the thread and retap it to a larger size (though you'll have to open out the hole in the flange too). Second is to drill out and insert a Helicoil - a threaded insert which restores the original hole size - but there may not be enough room for the hole required, but worth checking.
When it gets light enough, I'll have a look in my shed to find out whether there is still a spare head under all the years of junk... It was off the industrial version, so may need a few fittings changing, but might save the day.
Rob.
P.S. just can't remember which bits got used and which may still be there.
When it gets light enough, I'll have a look in my shed to find out whether there is still a spare head under all the years of junk... It was off the industrial version, so may need a few fittings changing, but might save the day.
Rob.
P.S. just can't remember which bits got used and which may still be there.
MagicalArmchair
Well-Known Member
Thank you Rob, that is exceedingly kind - hopefully it won't come to that nuclear option of employing another head! Interesting about Helicoils, just been googling them - I never knew such a beast existed, that gives me some hope that even if I do REALLY cock it up, there is hope for rescue yet!
Great news Ghostly :encouragement: - don't get it all finished now - what the hell will you do for the rest of winter in your shed?? (pheh, as if there is ever a shortage of jobs/ideas/improvements - my garage is awash with a half finished GRP/marine ply fridge box, newly epoxied locker hatches and washboards waiting for varnishing, and piles and piles of other fun boat bits
)
Great news Ghostly :encouragement: - don't get it all finished now - what the hell will you do for the rest of winter in your shed?? (pheh, as if there is ever a shortage of jobs/ideas/improvements - my garage is awash with a half finished GRP/marine ply fridge box, newly epoxied locker hatches and washboards waiting for varnishing, and piles and piles of other fun boat bits
)
RichardS
N/A
Good news. As I said, in my experience broken bolts or sheared studs - it's the same end result - can usually be removed with heat and penetrating oil provided there is enough metal proud of the surface to grip with something and you have the necessary access.
I think you now have one below the surface to drill and extract.
Richard
ghostlymoron
Well-Known Member
Quote Originally Posted by ghostlymoron View Post
Good news from Ghostly Towers! The broken bolt (not stud) was removed using a good squirt of WD40 (ran out of Plus Gas) and an 8" Stillsons + a short metal tube to give extra leverage. The bolt had been broken off for sometime judging by the condition of the gasket.
I've also removed the injector using a big spanner on the flats to twist it loose and the trusty Stillies to twist and pull plus a squirt of WD for good measure.
Another unwanted deletion hence re posted.
Good news from Ghostly Towers! The broken bolt (not stud) was removed using a good squirt of WD40 (ran out of Plus Gas) and an 8" Stillsons + a short metal tube to give extra leverage. The bolt had been broken off for sometime judging by the condition of the gasket.
I've also removed the injector using a big spanner on the flats to twist it loose and the trusty Stillies to twist and pull plus a squirt of WD for good measure.
Another unwanted deletion hence re posted.
ghostlymoron
Well-Known Member
No, Richard, it seems I was mistooken on that so it's all good news. Trouble is that the lighting in my shed is so bad that half the time I am working blind. Next project is to upgrade using donated strip light.
Good news. As I said, in my experience broken bolts or sheared studs - it's the same end result - can usually be removed with heat and penetrating oil provided there is enough metal proud of the surface to grip with something and you have the necessary access.
I think you now have one below the surface to drill and extract.
Richard
MagicalArmchair
Well-Known Member
I cleaned up and tested the elbow in my garage this evening, and although there is some pitting, it looks fine. I poured some thinners down the sleeve and nothing leaked out on the cylinder head end, so I guess its all pretty good.
After being cleaned up:
Before cleaning out:
The elbow and what's left of the gasget:
Is it worth painting or coating the inside of the exhaust elbow with anything?
After being cleaned up:
Before cleaning out:
The elbow and what's left of the gasget:
Is it worth painting or coating the inside of the exhaust elbow with anything?
ghostlymoron
Well-Known Member
I recall someone a while ago suggesting painting internally with 2 pack epoxy. You'd have to check the heat/chemical resistance. A suitable coating should extend the life substantially.
RichardS
N/A
I wonder whether you will ever be able to remove the existing corrosion sufficiently to enable the epoxy to bond firmly. It might be possible with rust converter and a drill + wire brush but it won't be easy. It would be much easier with stainless steel but then probably not as necessary although I have run an epoxy fillet around the outside weld of one of my YM stainless elbows as I understand that it's often the welds that go first and mine had a tiny crack in the weld which only opened up a fraction when the engine was running. Because that fillet was external I could sandpaper it really clean.
Richard
MagicalArmchair
Well-Known Member
I have sent an email to my tame West System epoxy representative (the very helpful and generally awesome people at Wessex Resins). I suppose the challenge would be treating the part of the elbow that is most likely to fail - between the outer and inner sleeve, which, of course, is where we have no access.
Richard, do you have any photos of where you put your fillet?
RichardS
N/A
This is where I ran the fillet after sandpapering off the paint and then degreasing with meths:
As you say, ideally this should be on the inside of the weld and perhaps, with a brand new elbow, it might be possible to run liquid epoxy down inside the elbow to fill the gap. However, I don't know how clean the elbow is inside and whether you could slop some meths around in there and whether that would be enough as you obviously couldn't roughen it up with sandpaper ...... a lot of imponderables there but as I was dealing with an old elbow I didn't even try it. However, it would be very interesting to hear whether anyone has actually tried anything like this.
Richard
vyv_cox
Well-Known Member
I replaced my very similar exhaust manifold (3GM30F) this season. A small water leak was exiting the flange and close examination revealed cracks between the flange, inner and outer tubes. However, I do not think that the cause was corrosion, I suspect it to be thermal fatigue as a result of stresses set up between the parts of different thicknesses as the engine heats up and cools down. The whole manifold was remarkably free of corrosion. So coating it with resin would not make a scrap of difference.
MagicalArmchair
Well-Known Member
Thanks Vyv, Richard, I'll inspect the weld around the flange very carefully now I have it cleaned up and leave as is if everything appears okay (well, I might paint it with hammerite...) . It looks in good condition, so I am not too concerned. I might replace it with a SS one when I service the engine next year anyway if funds allow and I don't spend all my money on other exciting boat projects...
pete
Well-Known Member
MagicalArmchair; I might replace it with a SS one when I service the engine next year anyway if funds allow and I don't spend all my money on other exciting boat projects...[/QUOTE said:
prv
Well-Known Member
Spray?
<google google>
Ah, apparently there's a newfangled aerosol version now
(Mine is a simple unpressurised can with a screw-on plastic spout for dribbling it onto things.)
Pete
ghostlymoron
Well-Known Member
You can see it's stainless just by looking at it. MS would not be that colour.
MagicalArmchair
Well-Known Member
New stud extractor arrived, and no luck. It requires the stud to be longer in order to be effective at 5mm on the 1mm to 6mm stud extractor.
To add to the fortunes spent already on trying to remove this, next up we have these: http://www.axminster.co.uk/irwin-t394100-set-of-7-power-grip-screw-extractors (the 3/16s one being the only one I am interested in of course).
I will be consulting http://www.kentmarineservices.com/ tomorrow also as I am somewhat losing hope and succumbing to despair! How hard is it to get the head off the engine if I do go for this nuclear option? Any decent guides that can be suggested?
To add to the fortunes spent already on trying to remove this, next up we have these: http://www.axminster.co.uk/irwin-t394100-set-of-7-power-grip-screw-extractors (the 3/16s one being the only one I am interested in of course).
I will be consulting http://www.kentmarineservices.com/ tomorrow also as I am somewhat losing hope and succumbing to despair! How hard is it to get the head off the engine if I do go for this nuclear option? Any decent guides that can be suggested?
bikedaft
Well-Known Member
have you ever drilled out a bolt or stud? its not that hard (usually!) as long as you get the hole centred initially.
sure its a last resort, but if engine was running fine then i'd be reluctant to take head off
sure its a last resort, but if engine was running fine then i'd be reluctant to take head off