Head Gasket - Need you experience

[Jon Olds]

Rally car head gasket has gone. The cooling system is pressurised. Stripped and removed the head.
Looks like the fire ring has not held on cyls 2/3, and there are witness marks of gas flow to the 5mm cooling holes 10 mm away from the ring.
Was an OE head gasket (I know, I'm a cheapskate).
ARP bolts/nuts fitted. (surely an improvement, if torqued right?)
I have ordered a MLS gasket for 40-50 quid, but would like your experience on whether this will hold.
Mixture looks spot on.
Everything looks (pistons/valves/combustion chambers) looks fine.
Runs a bar and 280hp.

Help appreciated.

Was trying to avoid £150+ gaskets, for obvious reasons.

 

[stumo]

Standard (Nissan) headgaskets should hold that no probs, was the head/block checked for flatness last time?

MLS gaskets needs blemish free and flatter surfaces to work, make sure you torque it down in the correct sequence....

 

[Jonesy]

As above you shouldn't have any probs running 1.0 bar boost on standard head gasket, been running 1.2 bar for a while without any probs.

 

[Jon Olds]

Are there any diy type ways of checking for flatness? I don't want to take the motor out. This is not an area
I have any experience of, as all my previous cars have been non turboed.
What will a machine shop do when I give him my head. I'm assuming he will use a surface plate and chock the head upside down at a known height then measure the head gasket face back to the surface plate, over the whole head. Is this right?? I'm an elec man not a clanky.
Clarification would be nice. Experience of a company in the NE area would be nicer still

 

[stumo]

you can use a straight edge and a feeler guage to check for flatness (my straight edge cost £70 :roll,

a rule usually isn't flat enough or stiff enough to work properly

 

[Jon Olds]

I have engineering steel rules, in good nick. If I buy a straight edge specifically, what do I ask for in the tool shop? (usually Cromwells and I do not expect any expertise behind the counter)

 

[stumo]

just ask for a straight edge, they're like a steel rule but much thicker, get one longer than the head....

there's different standards of straight edge, the cheapest will still be more than adequate (i needed one that had a certificate so it was more expensive).