Headgasket failure

[Pete Watson]

At last i have found out why my coolant is pumping out, not take the head off yet but have seen coolant on the bore walls, bugger!!

What i would like some help with is:

Best head gasket to buy 'I'm running 1.8bar with 3071', pretty sure it is 1.2mm thick, i read on here somewhere that over 1.6bar you should opt for a 2mm hg, is this right?

Would it be best to fit better head bolts/stud kit, if yes which ones.

I had my engine rebuilt at Hiteq, forge this and special that, the usual gear, i gather Hiteq has now gone, anyone else with good knowledge that can help me out would be great.

Best Rgs
Pete

 

[Mr GTiR]

If your engine was Hi Teq built then you'll have a HKS h/g. Never heard of a HKS one failing.

Depending on what compression ratio your pistons are designed to work with best will determin the thickness of h/g to use. Do you know what your HKS pistons have been spec'd for?

If your running that kind of boost then I would deffo get some head studs. Not sure which is best as the ones I have in mine are not available anymore.

 

[ashills]

all the hks pistons are the same comp arent they 8.5 so in the gtir are 8.3
if u run a 2mm headgasket will allow you to run more boost safely thats what my last engine had and was happy at 2 bar on with stock headbolts

 

[pulsarboby]

as ashills said.
if you need a hks 2mm h/g then i have one which has not been fitted long before engine was split and sold, i may sell that, but if you want a new one then graham goode racing are very reasonable.

as for headstuds!!! oe headbolts are more than upto the job, i hate those bl00dy studs lol, imo there uneccessary

 

[stevepudney]

as for headstuds!!! oe headbolts are more than upto the job, i hate those bl00dy studs lol, imo there uneccessary

Agreed, if fitted correctly the OE head bolts are fine.

and the 1.2mm head gasket should be fine at that sort of boost, mine runs 1.8-1.9 on a Tomei 1.2mm HG

Personally, I'd get a new set of head bolts from Nissan, whip the head off, clean up all the surfaces and assuming the HG isn't physically damaged, I'd re-use the HG and bolt/torque it all back down.

 

[Pete Watson]

Cheers guys,

I am a bit surprised at the HG failing, it has only covered 7k, i thought a HKS one was supposed to be the dogs nuts. I did a bit of research on here, i wondered if my problem may have been caused by to thin a HG for 1.8bar or poor clamping from the Nissan OE Bolts. I have read mixed opinions about ARP Bolts or Stud Kits. I have also read that you need to tighten the head bolts more with higher boost levels, is 1.8bar too high for OE torque settings? I guess quite a lot of owners are running these kinds of boost pressures, is HG failure going to plague me?

As the engine was built by Ian @ Hiteq and i never cut any corners just left him to use what he knew would be best, i thought it would have lasted longer.

Reuse my HG or fit a slightly used one, don't take this the wrong way but are you pulling my leg???

Any good reccomendation for the work to be carried out, it seems the Specialist are packing in.

Rgs Pete

 

[stevepudney]

no, not pulling any legs..........

Although I agree it is odd :shock:

once the head is off it might be worth getting it crack tested and making sure it's true and not warped as the head gasket might not be at fault.

once your 100% confident the head and block are good, re use the old gasket, it will be fine on new oe bolts, just make sure everything is spotless and perhaps tweek the torque settings up a few degree's

 

[pulsarboby]

as steve said above. if you are gonna reuse the same gasket then give it half a dozen coats of hairspray (not winding you up) also if its coated with silicone then make sure all the old silicone is removed (before coating)as it will cause a sealing problem if there are bits missing or stuck to head or block face!

lastly when you torque up the new bolts on the final setting it states 60 degrees well ignore that and give it 90 degrees that will really clamp it down and you shouldnt have a prob after that as long as the head and block face arent warped in any way.

 

[vss irvine]

i dont suppose you had a new oil pump and casing fitted at the same time as your rebuild?

ive heard of a couple of head gaskets failing due to the new oil pump cover holding the head up a bit.

apparently the block should be checked once the new cover is fitted, to make sure its not sitting proud.

this comes from a lad i know that rebuilds sr20det's for a living, its something else to look at?

 

[noriek2003]

post up a piccy of the headgasket when you get it apart.

 

[Pete Watson]

I managed to get the head off the car this afternoon, what a pain getting the inlet off, still all done.

Now for the bad news, the head gasket isn't the problem, the head looks good, the block however doesn't look good, the slit between No4 and No3 piston has closed up a bit, this means the edge of the fire ring isn't sealing correctly, on close inspection a tiny crack can been seen.

Is this something you have seen before?
Any serious thought on what i should do next?

To say i'm a bit annoyed would be an understatement

 

[pulsarboby]

as you rightly say it does appear to be block distortion which could be causing the problem.
however in all fairness this could have been caused by severe overheating in the first instance which may have distorted the block itself.

not seen one go like that before though, is the headface flat or is that distorted too?

 

[red reading]

could also be a heat affected zone created by a leak on the head gasket/head warping that has let the flame front push through at that point,i have seen a r1 with gas (my old one) that did similar it actually eroded that section away and scrapped the block

 

[Pete Watson]

The head face looks fine, the head gasket looks fine also, you can see where it has not been compressed onto the edge of the cylinder, it has left a line. We put a camera into the cylinder before removing the head, you could see a wet patck on the HG, once we had the head off the wet patch is the same place as the distorted section in the block.

 

[PobodY]

This is a novice question, so please be gentle:
Can you grind the cylinders out and fit over-sized pistons (or rings)? Or is the block essentially now an anchor? - It makes sense to me, but maybe that's not how it works in the real world.

 

[red reading]

The head face looks fine, the head gasket looks fine also, you can see where it has not been compressed onto the edge of the cylinder, it has left a line. We put a camera into the cylinder before removing the head, you could see a wet patck on the HG, once we had the head off the wet patch is the same place as the distorted section in the block.

was the block decked to start with?

 

[pulsarboby]

just looked at photo again and unless its the angle its taken at but it looks as though number 4 cylinder itself (liner) has distorted.
if you have a dial bore gauge it would be interesting to see how far thats out.
either way looks like the block is now fcuked though unfortunately for yourself.

 

[Pete Watson]

Looking at the blobk today it doesn't look like it was decked last time, i am wondwering how long it has been like this, more so with the mark on the hg where it looks as if it hasn't been compressed. I too think the block is shot, i was wondering if it could be repaired, if not anyone know of a good block for sale.

 

[Pete Watson]

The liner looks fine, in fact what you can see on close inspection is the top of the cylinder has pushed away from the liner thus exposing the top edge of the liner.

 

[red reading]

tbh i would just strip it all deck the block and fit a 2mm thick hg 87mm bore,as long as the bore is'nt distorted at the top