Hello,

we have tuned friends YB sierra, but after few runs engine starts to pressurize coolant until it blew from coolant tank. No overheating or pressurizing on crusing. We dissasamble engine. Found 205 block has usual crank around cylinder bolt between 1-2 cyl and partialy on 3-4 too.
But blew track on gasket is on oposite side of engine on cylinder no. 4.
Gasket is not burn, metal is like new, but black nylon sealant from gasket is blew away. We found, that there is not much made on gasket for solid pretension around cylinder.
Used OEM headbolds, tighten 120nm on assembly and checked 120nm on dissasembly. Around 5000km on gasket(overall on 1.1bar 340ps, now last 500km tuned on 2.0bar at 450+).

So my opinion is, that cranked blok doesnt have influence on gasket sealing(cylinders), isnt?

So may we change block(need reboring, simply almost whole build again) for non cracked + WRC gasket?

Or ghetto style, wireringed actual block(engine is out of car now) + YB1261 ?