Thread: TD5 exhaust manifold torque - increasing it with larger studs?

I fully agree with the statement below.

The idea is to let the manifold grow and shrink without ripping the head apart.
Your bigger studs and more torque are not helping.

I would make sure the manifold studs have enough clearance for thermal expansion and the torque is high enough to seal but low enough to allow movement.

High tensile bolts studs are stronger but not as elastic as lower
spec bolts.

If you fit a longer stud with a spacer between manifold flange
and the nut you are lengthening the stud so its overall elasticity
has also increased might be worth a try.

Originally Posted by twr7cx

According to Rave the torque setting for the TD5 exhaust manifold is 25nm. I have M10 studs now in the 1st and 5th, any ideas if I can safely increase the torque setting on these (and if so how much)?..

The V8i manifold bolts get tightened to 51Nm and I believe these bolts are 3/8" so just smaller than M10. BMW quote 47Nm for M10 bolts and studs, and the Td5 uses an M10 bolt for the timing chain guide and specify 45Nm. Have seen other references quote 55Nm for M10 bolts at grade 8.8.

If you are wanting to try a higher torque then I would go with 45Nm for the M10 studs. The longer studs with spacer collars as suggested above is a good idea.

25Nm on a M8 stud will give a clamp load of around 1.5 ton per bolt.
47Nm on a M10 stud will give a clamp load of around 2.3 ton per bolt.

Increasing the torque and clamp load will increase the stress on the manifold and head from thermal expansion.
I wouldn't do that.

I noticed some time ago that on one of the Toyota 6 cylinder diesels they have a sliding sleeve between 3and 4 on the exhaust manifold.
Presumably this is to reduce lengthening of the manifold when hot. Looks like a good idea.
I wonder if it would be possible to do the same with 2x TD5 manifolds to make one ? It should also reduce the warping problem.

Regards Philip A

Originally Posted by PhilipA

I noticed some time ago that on one of the Toyota 6 cylinder diesels they have a sliding sleeve between 3and 4 on the exhaust manifold.
Presumably this is to reduce lengthening of the manifold when hot. Looks like a good idea.
I wonder if it would be possible to do the same with 2x TD5 manifolds to make one ? It should also reduce the warping problem.

Regards Philip A

Isuzu manifolds use holes that get larger the further you get from the centre. Much easier to replicate.

Apologies in advance for the thread hijack (saves having another thread in what is already a cluttered section...and this one seemed to have run its course ).

I'm planning to pull the exhaust manifold in a few weeks to remove a broken stud where the EGR pipe enters the manifold. In doing this I'm bound to have a few dramas removing the actual manifold studs - it would be very foolish and unwise to pretend that at least one or three are going to shear or the nuts are going to crack, etc.

With that in mind I have replacement studs and nuts ready to go. Crikey, I've even got a right sized helicoils on my ebay watchlist if it really goes pear shaped.

The logistics of getting the manifold shaved (if it needs it, but let's assume it will) aren't pretty in the rural town I live in. So I thought maybe there was merit to replacing the current manifold with a new one as there's every chance this one's done the full 300,000kms that the vehicle has travelled.

Would you run a mile from this one?
Land Rover Defender 90 110 Discovery 2 TD5 Turbo Exhaust Manifold | eBay

Or can it not be that bad? Surely the Chinese can do cast metal stuff as well as they make iphones, etc.

I wonder if there's anyone here that has paid Bruce Davis' mob the $950+ that they have on this one?

Land Rover TD5 Sports Exhaust Manifold Modification - 7% Off!

What's interesting is that the manifold on the right of that photo seems to still have the webs intact but the other one (minus the EGR inlet) does not.

Maybe I should have ponied up the cash for the Allisport one last weekend when ebay had their 15% off deal. It came down from $1219 delivered to something around $1050 IIRC.

Cheers for your thoughts fellas.

Originally Posted by Dougal

Isuzu manifolds use holes that get larger the further you get from the centre. Much easier to replicate.

I think the key is to have sufficient clamping force to seal, but not too much to prevent movement from thermal expansion.
I have used belleville washers in the past for a joint that was required to move due to thermal expansion.

I liked the look of this one. No connecting webs, comes with slotted 1st and last position stud holes, plus with high strength bolts.

http://www.landrovertuning.com.au/di...ery-2-td5.html

I have no personal experience with this as I still have the original manifold with broken bolt in first position.