Thread: td5 exhaust manifold , grinding out the web.

+1 for single slice, I just sliced my web's with a grinder 1 slice per web, so far so good. I did also open up the stud holes a tad more

When I replaced the head gasket I found 3 studs snapped off. Went through and replaced them all with longer ones, I drilled out the manifold holes as well. I used an angle grinder and a cutting disc to de-web the manifold along with a die grinder to clean it up ( as others have said, use what you have) personally I don't think it's the manifold expanding that is the problem, more like the LACK of expansion compared to the aluminium head, but anyway, when I refitted the manifold I used some spacers on the longer studs ( this is similar to how my Prado is setup from factory)
The Disco has now covered about 20k so far and no issues.

Cheers
Redd

Originally Posted by Reddirt204

When I replaced the head gasket I found 3 studs snapped off. Went through and replaced them all with longer ones, I drilled out the manifold holes as well. I used an angle grinder and a cutting disc to de-web the manifold along with a die grinder to clean it up ( as others have said, use what you have) personally I don't think it's the manifold expanding that is the problem, more like the LACK of expansion compared to the aluminium head, but anyway, when I refitted the manifold I used some spacers on the longer studs ( this is similar to how my Prado is setup from factory)
The Disco has now covered about 20k so far and no issues.

Cheers
Redd

Have had one TD5 exhaust manifold warp, and was advised to replace exhaust manifold studs with 10mm TDi300 studs (but not to change the centre 2 studs as drilling these out goes into coolant area in head), which required drilling out the holes in exhaust manifold to take 10mm.
Faced manifold, changed out to larger studs and that did work well, but was a lot of fiddling with drilling and tapping out for larger studs.
Next TD5, I drilled out the manifold holes to take 10mm and had the manifold ceramic coated (to dissipate heat better), BUT I did not change the studs from the 8mm.
I was thinking that the warping might be due to the manifold expanding but not having anywhere to expand to, and that by having some space in the holes around the 8mm studs, that might allow for expansion without warping.
So far I have covered over 50K and no issues as far as warping, which might be down to either the ceramic coating, the larger holes in the manifold, or both, but it seems to be working and I drive long hauls in hot areas, so it would be getting pretty hot in the exhaust department.

Originally Posted by Four Loko

+1 for single slice, I just sliced my web's with a grinder 1 slice per web, so far so good. I did also open up the stud holes a tad more

Ok I concede defeat.




You can even see the scrape marks on the gasket from the manifold dragging along it from expansion.

Originally Posted by Four Loko

Ok I concede defeat.




You can even see the scrape marks on the gasket from the manifold dragging along it from expansion.

What sort of EGT's are you getting?

Originally Posted by shack

What sort of EGT's are you getting?

I try to not let it get above 750/800 tops on full mang climbs hopefully my gauge gives me an accurate result...

Free way driving its normally sitting like 350-400

Maybe enlarging the stud holes on the manifold was not a good idea, too much wiggle room ? I don't actually think the manifold is warped I think the gasket has just stress fractured from the movement.

Will pull it off next weekend and look, waiting for a backup gasket first.

Originally Posted by Four Loko

I try to not let it get above 750/800 tops on full mang climbs hopefully my gauge gives me an accurate result...

Free way driving its normally sitting like 350-400

Maybe enlarging the stud holes on the manifold was not a good idea, too much wiggle room ? I don't actually think the manifold is warped I think the gasket has just stress fractured from the movement.

Will pull it off next weekend and look, waiting for a backup gasket first.

That's certainly getting up there, and 800 sustained will probably cause more issues than a wandering manifold.

The manifolds I've done have had the entire gullet removed, I've never had to go back........yet.

Looking at your manifold though it seems to be moving an unbelievable amount, never seen one that well travelled.

The issue I see with the single cut method is that it encourages most of the movement to take place at the bottom of the cut, which theoretically should cause cracking at some point.

Cheers
James

Seems in Brit Land there are a lot of kits with updated studs and spacers i.e.

Land Rover Discovery Defender Td5 Extended Wurth Exhaust Manifold Stud Kit HD | eBay

Used these on the Darkside Development manifold and will be using them on the D2a when I change the CHRA
20211107_115250.jpg