exhaust manifold

[caiblue]

anybody know the length of the studs that hold the cat to the manifold please? - I know that they are M10 X 1.5 thread but not sure of the length,

car is a FOCUS 1.8 TDCI 2004 115 BHP MODEL,

cheers,

 Gordon.

[JW1982]

The total length of the studs is not specified in the technical documentation.

These studs are nit fully threaded but have a non threaded section in the middle. One end of the stud has 14 mm (M10) thread and the other end of the stud has 26 mm (M10) thread. The length of the non threaded section is unfortunately not specified. 

[caiblue]

thanks for the reply - I can get them at a total length of 46mm or 52mm, might order both so I'm not stuck once its off!,

[JW1982]

Be aware that those studs are not made of ordinary grade steel. You should only use studs that are made of 10.9 or (preferably) 12.9 grade steel.

Again the steel grade of the bolts is not listed in the technical documentation. Personally I only use 12.9 grade steel for applications like these.Because of the relative large temperature differences which make the material continuously crimp/expand normal 8.8 grade steel studs will stretch and eventually come loose or break.

[caiblue]

On ‎10‎/‎29‎/‎2016 at 3:50 PM, JW1982 said:

Be aware that those studs are not made of ordinary grade steel. You should only use studs that are made of 10.9 or (preferably) 12.9 grade steel.

Again the steel grade of the bolts is not listed in the technical documentation. Personally I only use 12.9 grade steel for applications like these.Because of the relative large temperature differences which make the material continuously crimp/expand normal 8.8 grade steel studs will stretch and eventually come loose or break.

would nylock nuts be suitable for fitting these? I have them here but haven`t got any plain nuts! cheers.

[JW1982]

Nylock nuts are not suitible for exhaust purposes. The heat of the exhaust will simply melt the nylon part of the nut and affect the locking ability of the nut.

Personally I would use regular nuts combined with high quality locking washers (for example nordlock washers) or 1-piece steel locking nuts.

Next to this the studs and nuts must be made of the same grade steel. Combining 2 different grades of steel should be avoided. The part made of the lowest grade steel affects the strength of the mechanical joint so the connection will only be as strong as the weakest part. 

[caiblue]

17 minutes ago, JW1982 said:

Nylock nuts are not suitible for exhaust purposes. The heat of the exhaust will simply melt the nylon part of the nut and affect the locking ability of the nut.

Personally I would use regular nuts combined with high quality locking washers (for example nordlock washers) or 1-piece steel locking nuts.

Next to this the studs and nuts must be made of the same grade steel. Combining 2 different grades of steel should be avoided. The part made of the lowest grade steel affects the strength of the mechanical joint so the connection will only be as strong as the weakest part. 

thank you. :-)