K series water rail clearance and bolt torque

[CharlesElliott]

I just replaced the leaking water rail gasket on my k series....should have loosened the engine bolts rather than spending 30 minutes trying to maneovure the rail back in!

 

Anway two questions:

 

- what torque should the 2 x M6 bolts at the head end be torqued to? Workshop manual suggests 25Nm but I think the rail is different on a Caterham and that is high for M6. There is another M8 bolt further down the rail which I'm less worried about.

 

- I realise that I have almost zero clearance (maybe 1mm?) between the water rail and the chassis diagonal. The rail has quite a substantial groove in it from hitting/rubbing the diagonal. My car probably isn't 100% straight but what sort of clearance is expected? The only other way I can think of getting clearance is to loosen the engine mounts and shift it but I don't think that is going to gain me more than a mm or two.

 

Charles

[John Vine]

For M6, I'd torque to 9Nm. It'll be the same as the cam cover. And yes, 25Nm is much too high.

 

I can't help with Q2, I'm afraid. It's a long time since I owned a K.

 

JV

[Englishmaninwales]

Charles

I needed a shortened bolt on one of the fixings as the bolt bottomed out. This was the cause of the leak in the first place.

(Sorry I know this doesn't help your specific query!)

Malcolm

[7 wonders of the world]

Charles make sure you do a dry fit first and nip the two rail bolts up then see what clearance you have on the third rail bolt toward to other end of the rail,

Use suitable washers to shim this clearance otherwise the flange will pull away when this front mount is tightened up and p1ss water out again!

[CharlesElliott]

Thanks - I was going to go for 10Nm. And thanks for all the input - the old gasket was well and truly knackered.

 

Just been replacing the camshaft oil seals as well.

 

Here is a picture of my clearance (or lack of it!).

[revilla]

I think the 25Nm applies to the front M8 not the M6s. Unfortunately when I did mine through lack of experience I didn't hear the alarm bell telling me it was far too much. Took me ages to pick the remains of the sheared bolt out of the head. Luckily the bolt went before the head thread.

 

Sorry can't help on the clearance, mine's an SV!

 

Edited by - revilla on 30 Aug 2014 06:38:25

[Grubbster]

Charles would it help to put a thick washer under the LHS engine mount to tilt the engine slightly? It might give you a little clearance?

[CharlesElliott]

It might well do Steve. I'll loosen off the mounts and see what I can do.

[oilyhands]

A major cause of leakage is poor alignment at the front bolt. I normally do up the rear bolts and then assess the alignment at the front bolt moint point, sometimes the rail is a good way out from the mounting on the head, when the bolt is done up it levers the rear of the rail away from it's mounting flange and causes leakage, in this instance I space the mount tube with washers of the appropriate thickness, similarly the front mount can be too close, preventing the front of the flange from sealing, in this case relieving the tube a little will help. Make sure the flange is flat and that the bolts aren't too long. Tighten them to 11nm.

 

Oily

 

 

Edited by - oilyhands on 30 Aug 2014 08:37:54

[CharlesElliott]

Thanks Dave.