Thread: Broken manifold studs, AGAIN

All done, i had to have it done by a mechanic this time as i don't have the nessesary tools to drill and re-thread the new holes for the larger studs.

I did grind the webbing out on the new manifold, the mechanic did say it made sense that it will help in stopping the warping of the manifold which inturn breaks the studs.

He is also going to recommend this modification to the other D2 customers that have had this problem.

Baz.

Just to add information for your consideration.

After 9 years and 95000km my studs went, four of them and not being all that handy with such work went to Graham Coopers for the job.

They expressly advised not to use the modification suggested by redback as it weakens the manifold, so that instead of breaking studs you end up with a cracked manifold, which is way more expensive to replace than repairing studs,

choose wisely.

ide like to see that

i as part of my apprenticeship ive welded up and modified alot of cast manifolds.. i wouldnt hesitate to preform this mod.

cheers phil

Baz, the only thing I'd be still concerned about is movement,,,

as in,,

how can the nuts be tight?
if the manifold moves along the elongations?

or maybe put another way,,
if the removal of webbing works,
why the need to elongate the stud holes?


I do understand you're at the hair pulling out stage,,,
(joke please Phil--)

Great Mod, yes it will work as i did something very similar to a Volvo 6 i had a few decades back.... it would warp and break studs, so after eventually finding another exhaust manifold, we ground cut and modified... never caused another issue again... i later abused it to its limits by racing it and all that extra heat was never an issue on it failing...
They crack due to stresses off not being bolted FLAT....

Originally Posted by Pedro_The_Swift

Baz, the only thing I'd be still concerned about is movement,,,

as in,,

how can the nuts be tight? you tighten them with a spanner? dont get what you mean?
if the manifold moves along the elongations?
the elongations are ther more so for a ''just in case'' because the majority of metal is in the center of the manifold thats where the bulk of the heat will gather, that is what causes the manifold to expand and contract at vastly differant rates to the extremities of the manifold. this in my oppionion is what causes the studs to break/come loose, not studs come loose then manifold warps(although both are highly plausable)

or maybe put another way,,
if the removal of webbing works,
why the need to elongate the stud holes?
from my point of view i think the webbings, while adding strength, are really just leftovers from the casting process. with them removed there will be alot less ''pulling'' of the ends of the manifold.


I do understand you're at the hair pulling out stage,,, this was a post from last year, baz hasnt done it again
(joke please Phil--)

cheers phil

Sorry to hijack ya thread Barry, just wondering, does anyone make an aftermarket turbo manifold for TDi Discos?

This is the manifold I have for my Falcon, surely it wouldn't be a big call for one to be made. Anyone keen on this, I could instigate if people are keen on a group buy situation.

Holds a pretty heavy turbo and will be taking some pretty decent temps too.

Originally Posted by sclarke

Great Mod, yes it will work as i did something very similar to a Volvo 6 i had a few decades back.... it would warp and break studs, so after eventually finding another exhaust manifold, we ground cut and modified... never caused another issue again... i later abused it to its limits by racing it and all that extra heat was never an issue on it failing...
They crack due to stresses off not being bolted FLAT....

Absolutely!

Same when I was racing 2-strokes. Even though they were single cylinder the manifold would crack if the gasket was reused which didn't allow the flange to bolt down properly onto the head. Also had to make sure the manifold studs were torqued properly and tie wired in place (which was also a reg) This said EGT's were up to 1050F which probably also produces a lot more movement in the parts than what a TD5 gets.