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mgf
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Discussion Starter · #1 ·
I am about to remove the head on the MGTF 160 (again). How good are the redesigned N series head gaskets or should I stay with the MLS type?
 

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mg_tf
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As I see it, the fundamental question here - before considering which type of multi layer gasket will be most suitable - is :- is any type of multilayer gasket acceptable to use?
Surely it can only be established whether to use a multi layer or elastomer once the head has been removed, at which point a multi layer gasket will be acceptable if all liner heights are a min. of 3 thou above, and all of an even height. If this criteria isn’t met, then an elastomer gasket has to be used.
Of course, the ‘again’ may point to you having prior knowledge of this particular engine, and you already know the liner situation.
 

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mgf
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Discussion Starter · #3 ·
As I see it, the fundamental question here - before considering which type of multi layer gasket will be most suitable - is :- is any type of multilayer gasket acceptable to use?
Surely it can only be established whether to use a multi layer or elastomer once the head has been removed, at which point a multi layer gasket will be acceptable if all liner heights are a min. of 3 thou above, and all of an even height. If this criteria isn’t met, then an elastomer gasket has to be used.
Of course, the ‘again’ may point to you having prior knowledge of this particular engine, and you already know the liner situation.
Good point, thanks for mentioning the liner heights.
I have either a hydraulic lifter stuck, or perhaps a valve seat has come away and is jamming one of the valves open. Number 1 cylinder is at 20lb and the other 3 are at 165lbs. I had the head redone about 5000klm ago after the keyway in the crank pulley failed. the car was at idle when it failed. 2 minutes before I was competing in a hillclimb. So the head will have to come off again for inspection. I am in Australia and I like to have all the parts before I start. I have an elastomer gasket just in case the liners have moved but was interested in any comments on the China N series gasket. I used a MLS last time.
 

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'06 MG ZR +120 (HQM) '04 MG ZR 105 (IAB)
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How good are the redesigned N series head gaskets or should I stay with the MLS type?
The SAIC head gasket is an MLS type ;)

Having used one in two engines now, I would have no hesitation whatsoever in heartily recommending it. I fitted one in a ZR 120 in early 2013 - the liners were below the usually recommended 3 thou (they were around 2 thou, and whilst close, they were not all identical heights either). The car has now covered over 63k miles in the eight years since, and has had no issues whatsoever (not even needed any coolant topping up aside from the full coolant changes at the recommended intervals). The full XPart kit was fitted: includes the stronger bottom oil rail and 10.9 tensile long bolts; expensive, but well worthwhile in my opinion.

The other was a 105 with flush liners - these were raised using the 3 thou shims now available from XPart - and although the car in question has only covered around 1500 miles in the two years since, everything is still looking good so far.

They have been around in the NAC/SAIC cars for long enough now for it to be apparent that the Chinese built engines are no more likely to have a head gasket issue than any other make of engine - if only Rover had developed such a gasket sooner, perhaps their cars would be held in better regard?

Frankly, there are enough people who still have subsequent problems after fitting the two-layer MLS and shim, that I would now routinely disregard that as an option.

One of the major issues with the K series is lack of decent coolant flow into the head - an issue that can be easily and largely effectively alleviated by grinding out the overmould around the coolant ports in the head using a burr on a mini drill. The overheating og the head face due to the lack of flow is what leads to softening of the head face and subsequent indentation of the head by the gasket fire rings, and a consequent HGF. The SAIC six-layer gasket has no solid fire rings, so improving coolant flow through the head and fitting the SAIC gasket removes this major route to HGF.
 

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It would be helpful to know first where the gasket failed. Of course, you will only know this once the head is removed. All the comments on liner height et al are valid. 5K Kms is not good but I am afraid that unless one has an experienced and careful mechanic, one never knows if the job is being done correctly or in a hamfisted way. Here there is one mechanic I know who has worked on 'K' series engines (mainly Landrover) for years (late 40's) and knows his stuff. If you have a young mechanic with no experience of the 'K' and is not willing to learn, then you are in for trouble whatever gasket is used!

In your instance, you do not have the problems one faces when relying on a garage. But you may not possess all the special tools required to measure liner heights, head surface et al. To do a proper job, you will need to invest in these tools (unless you already have done so).

I would be interested in the N series gasket performance when fitted to a Powertrain built K.

Best of luck. Tell us how you get on.
 

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'06 MG ZR +120 (HQM) '04 MG ZR 105 (IAB)
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It would be helpful to know first where the gasket failed.
I don't think it has - he needs to take the head off to attend to a suspected damaged valve seat;)

I would be interested in the N series gasket performance when fitted to a Powertrain built K.
See my earlier post. There are quite a large number of people who have fitted the SAIC gasket to an MG Rover/Powertrain built engine, and I haven't heard of many (or indeed, any) having issues further down the line.
 

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mgf
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Discussion Starter · #8 ·
OK, did you check the liner heights and evenness last time?
One liner was out but was so little that I didn't have a feeler gauge thin enough to measure. The others were all .3T, I think the short one was .29999999. But the head is being removed this time due to the hanging valve. the gasket has not failed.
 

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mgf
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185 Posts
Discussion Starter · #9 ·
It would be helpful to know first where the gasket failed. Of course, you will only know this once the head is removed. All the comments on liner height et al are valid. 5K Kms is not good but I am afraid that unless one has an experienced and careful mechanic, one never knows if the job is being done correctly or in a hamfisted way. Here there is one mechanic I know who has worked on 'K' series engines (mainly Landrover) for years (late 40's) and knows his stuff. If you have a young mechanic with no experience of the 'K' and is not willing to learn, then you are in for trouble whatever gasket is used!

In your instance, you do not have the problems one faces when relying on a garage. But you may not possess all the special tools required to measure liner heights, head surface et al. To do a proper job, you will need to invest in these tools (unless you already have done so).

I would be interested in the N series gasket performance when fitted to a Powertrain built K.

Best of luck. Tell us how you get on.
Julian, some good points, I understand what you mean about attitude and willingness to learn. I have one mechanic in the Brisbane QLD Australia area that I trust. He sorted out the mess the car was in when I got it with only 52,000Klms on the clock. The engine was out 2 teeth, exhaust and inlet manifold gaskets were for the 1300cc engine. there were signs on nuts and bolts that a multi grips tool had been used! Unfortunately my trusted mechanic has so much work at the moment that he can pick and choose what jobs to take. He doesn't like my job.

I have a well equipped very big garage, air tools, sockets, spanners gauges, electronic OBDII readers (5 different types including PScan) and my friend built motorcycle race engines and has all the strait edges I will need. And he will help too as we are both retired. Sadly my wife will not allow me to get a 2 post hoist until I build special cupboards and folding quilting tables in her sewing room.

the real worry Julian is the head gasket did not fail. I have a valve stuck open. It is one of the following, bent valve, dirty hydraulic lifter, or (cringe) valve seat has come away and jamming the valve open. I will keep you informed.
 
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