every bolt snapped

[catsey]

manifold bolts replaced at 20k 10yrs ago now come to replace manifolds every one snapped what are the odds these were SS bolts.

[brake fader]

were they rusty? if not then most likely to be ss and a ball ache to drill out.

[OldGermanHeaps]

How deep are they snapped in?
I know its rough, but you could molegrip a nut over the broken end and weld it on, mild steel will weld to stainless and the intense heat will loosen it, it just wont be pretty. You will want to block the ports off and protect the surrounding areas as it will spatter like fk.

[Pope]

There's definitely a case for replacing the OE bolts for studs with nuts and washers - like the air-cooled engines....at least with them some heat prior to undoing generally helps.

Not helpful now, but, did you use an impact gun to shock them out or a bar/ratchet? Forgotten how many I have done over the years but the most effective way I have found is a sharp tap with a hammer, a well fitting impact socket (6 sided) and a high-torque impact gun - if they don't all come out, if some do break out of the 12 you might lose 2 or 3.....

What's most galling is that the bolt is generally shiny-clean where it snaps; the dissimilar metal corrosion at the threads is what does it.

[OldGermanHeaps]

If you do use stainless again marine antiseize is good for that

[Krikkit]

OldGermanHeaps said:

How deep are they snapped in?
I know its rough, but you could molegrip a nut over the broken end and weld it on, mild steel will weld to stainless and the intense heat will loosen it, it just wont be pretty. You will want to block the ports off and protect the surrounding areas as it will spatter like fk.

This is a good technique for stuck studs/snapped bolts, I've rescued ones which have snapped off flush with the mating surface before this way - worth investing in a can of anti-spatter spray if you're welding to stop any further damage to metal surfaces, obviously plug the ports up too.

Definitely sounds like a switch to stud and nuts is worth doing, dunno why you wouldn't do that anyway from a design perspective - seems standard on most engines.

[Eddie Temple]

Have you thought about titanium studs and K nuts for a long term solution. Not cheap but do the job. The K nuts are a one time use as they distort when torqued up but will not undo unless required.

I bought some for my 996 Turbo from verboten motorsport in the UK and they were well made and worked perfectly to replace my OEM rusted bolts

They also supply drill kits to allow for drilling out snapped header bolts
It’s bit of a bugger to drill the studs out especially if stainless but the drill jigs help with locating your drill dead centre with the snapped off stud

[GT6 Jonsey]

Beg, buy, borrow a Stomski jig. Makes life so much easier
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[anonymous-user]

I guess the exhaust guy was right when he told me to prepare for a big bill if he change the manifold on the boxster

[Mike Oxlong]

Just seen this on the Bay of E !


https://www.ebay.co.uk/itm/313536230310?hash=item4...

Looks similar to the Stomski drill jig

[OldGermanHeaps]

A wee engineering tip, if yoi do need to drill them, centre punch them, and buy self centring door hinge drill bits with the sprung sleeve. Choose ones where the drill bit is held in with an allen screw as the actual bit inside is invariably crap, then you can swap the bit out for a presto or similar.