Head Gasket...

[wagon]

Hello all!

I have blown a head gasket on my alloyhead crossflow... The water jacket at the back end of #6 blew out (it was blowing water out of the exhaust port! ). There is minor corrosion on the head. The gasket is a Monotorque and is about 50000km old. Why did it fail? I run inhibitor always and it has not been cooked. What is the best gasket set to run on these old girls? Do headbolts normally need changing too or should they just be checked for stretch?

Kendall.

 

[addo]

Stretched bolts, overstrength coolant, warped deck, inadequate relax time between torquings - not in any order, but possible contributors.

 

[wagon]

OK, so I should have the head skimmed, check the block deck for warpage, install new head bolts and maybe go back to genuine coolant.

What gasket brand is suggested? Head bolts? I built this motor about 5 years ago and it has been trouble free until now - it is mostly a stocker with some headwork and a small cam (plus efi).

How long to wait between head bolt torquings?

Oh, and the car doesn't do a lot of long trips anymore - mostly to work and back (around 5km each way) - it chews too much fuel to go anywhere much in.

Thanks!

Kendall.

 

[addo]

I advocate forty minutes between first and second stages, then 24 hours until final torquing.

Leave antifreeze/inhibitor out of the coolant for a week or so of running, giving the gasket time to fully bake on those printed-on polymer passage seals.

Head bolts - just watch the torque process - if one seems to take more degrees to reach tension, it's suspect. New name-brand bolts would probably be too dear for most tastes. Check your thread depths and bottoming conditions (including where the plain section of shank runs out).

Just check the block and head - 6 thou of warp or wind on the head will pull flat, but the block will not be so docile. If the head's perfect, it follows reason that the block could be up to six thou out and there'll be no worries.

That aside, one head gasket in five years of sporadic use probably isn't too bad.

 

[wagon]

Thanks for your help Addo. I guess I was dissapointed because the original head gasket lasted 300 thousand km -but- the car used to do around 30thousand km/year - lots of long trips - but now hardly ever gets to see 100km/hr. I will check all the bolt holes and bolts for stretch.

Kendall

 

[wagon]

Duplicate post.. sorry!


Kendall

 

[wagon]

I ordered the new set of head bolts today - about $50 from Repco - Quite hard to get, had to be ordered specially - some suppliers didn't even list a catalogue number for them! One bloke (an engine builder) I talked to said just reuse the old bolts - but for $50 I can be safe rather than sorry. When I get them I will post what brand they are and the part number - maybe it will save someone else the mucking around.

 

[wagon]

I found some new head bolts - a bit difficult to find, were a special order... Anyway, they are 'Durapro' or 'Precision International' brand and the part numbers are HBK3555D / XD6065A-B. I got them from Repco for $49 for the set.