matching gasket to bore?

[EV0300]

Im wanting to put a MLS head gasket on my 180sx but i cant find one standard bore which is 83mm, a guy on ebay is selling an 85mm cometic claiming i can use it on the 83mm bore. is this true? will it last? just doesnt sound right to me, thought id make sure before i commit to buying one.. cheers

 

[VIN18M]

It'll give you 1mm clearance around the cylinders which should be fine. If you were running an 85mm bore and were using a head gasket for an 83mm bore then you'd have issues.

 

[EV0300]

Will it change c/r? Ill have to adjust my tune to suit then?

 

[MDK87]

I used a cometic street pro gasket set on my CA18 and it fit perfectly.

Here's an 83.5mm gasket.

http://www.ebay.com/itm/Cometic-H2207SP5051S-Metal-Head-Gasket-CA18DET-83-5mm-x-051-/301142985304?pt=Motors_Car_Truck_Parts_Accessories&hash=item461d854a58&vxp=mtr

Alternatively, message ericsperformaceparts on ebay US. They have tonnes of OEM and aftermarket Nissan gear.

http://www.ebay.com/usr/ericsperformancepartscorp?_trksid=p2047675.l2559

This is my own personal opinion and I know a lot of people swear by cometic but mine leaked combustion pressure into the coolant ports after a few thousand km's.
I did everything to the best of my knowledge. I had both faces machined to 50 RA, sprayed the gasket on both sides with copper (hylomar equivalent), used ARP studs, lubed and torqued as directed, heat cycled, re-torqued. I only put 18psi max boost pressure through it. Maybe I shouldn't have sprayed it with the copper.
It was probably something I did, but I think next time I assemble an engine I'll either use OEM graphite or HKS MLS with better studs.