VX head gasket

[GuyT]

The last time I did any engine work was many years ago on X flows and pre-x-flows. It would seem that the head gasket is letting oil into the coolant system as the porousity problem of these heads was addressed by sleeving the oil way in the head (carried out by V Tuning some time ago) I would like to do the gasket myself and wondered if anyone has got a list of what I will need - gasket (cometic or metal ?) headbolts, perculiar spanners etc. and can any one give me any tips, pointers, pitfalls I need to be aware of. If i can leave the carbs and manifold on the head this would be a bonus as I want to do this with the minimum of messing about re-balancing etc.

Any advice would be greatly appreciated.

 

best regards - GuyT

[Paul Deslandes]

Guy

 

random order of thoughts but I think most of the issues are covered:

 

You can take the head off c/w inlet manifold and carbs. Just be careful when lifting it all off that you have disconnected everything before you start. Depending on how long its been on you may need to give it a good tap with a rubber mallet to break the seal. There are two tubular dowels locating the head so it has to come straight off.

 

There are two alternative types of head bolt which should be replaced with new ones as they stretch. Check the SBD website www.sbdev.co.uk to identify which ones you have or take an old one into your Vx dealer to make sure they're right. The SBD site also has the details of tightening torques, and loosening and tightening order as well. The bolt heads are different for each type, either male or female torx and they are different lengths. Its obvious if they're right or wrong. And you'll need a Torx bit to suit and a torque wrench. Suggest when you've got the bolts out take one into Halfrauds etc and match up.

 

Check out the SBD cam cover mod to improve oil supply as well. Its very easy to do and stops the oil staying up behind the baffle plate when you're driving in a spirited manner.

 

If you're running standard compression ratio or even a bit higher you can use the standard Vx head gasket with no worries.

 

Depending on how much you take off the head in terms of bits, you'll need a head gasket, exhaust gasket, cam cover gasket although this can safely be reused so long as they're not crimped or nicked. If you remove the top hose coupling you'll need the gasket and funny 'D' shaped 'O' ring as well.

 

Whilst you've got the head off are you going to lap the valves while you're there!?

 

You have to remove the cam shafts to undo the head bolts so you'll need two seals and a new belt. Make sure you check out the camshaft alignment BEFORE you take off the belt so you know how to get back to the right place. Its best to have the crank at pistons halfway down to avoid any risk of piston/valve contact during dismantling, in case one of the camshafts rotates under coil spring pressure when you take the belt off. You'll have to remove the camshaft pulleys to replace the seals and its easier to lossen the centre bolts whilst the belt's on and everythings tight. Ohterwise you'll have to clamp the camshafts in a vice to loosen the allen headed bolt. Not a big deal, just a bit easier!

 

All the gaskets and seals, including the head gasket, are in a top-end reconditioning gasket set. You'll just need a new cam belt (make sure you get the right one as I believe the tooth profile can vary if you have an LN (low noise) engine.

 

You'll need some sealant to go under the front camshaft bearing caps. You only need a smear but they can leak if you don't do it. Do not under any circumstances use RTV or silicon sealnt as it can break up and get into the oilways with disasterous consequences. Camberly Autos do a suitable sealant or, better still, get the Vauxhall stuff specified for sealing the sump gasket.

 

The Haynes 16valve Astra book is extremely useful.

 

You can get all the bits from SBD (no association, just a satisfied customer)

0208 391 0121.

 

Hope some of this helps.

 

Best of luck

 

 

[Paul McKenzie]

Guy,

 

IMHO your problem isn't the HG, but the fact that the sleeving of the porous oilway didn't work...that's what you need to sort.

 

Sorry,

 

Paul