Leak Down Results on MHG before start up

[supraswans]

Does anyone do leak down test after new MLS HG before completing assembly? Are heat cycles necessary for gasket to seal properly? My leak down results before start up are not good. Head was tested, machined .008, new stem seals. Block was decked 90k ago. Compression was good before disassembly. Leak down and chemical test confirmed BHG. Since the block shined up I have tried new MHG again before completing assembly or deciding to deck the block again or go back to composite gasket. Please share your experience.

 

[supraguy@aol]

Leakdown or compression test after rebuild might not be too conclusive, if you have honed the cylinders and/ or replaced the rings. They need time to seat.

PS- If I was only pushing 12psi or less on a stock turbo, I'd probably go with a composite hg and ARP's, especially if you suspect a less than perfect deck surface.
I did this setup for 3 years, up to 15psi, no issues.

 

[supraswans]

I agree Supraguy, this is not a new build but I did add oil to rings before setting the head and doing a leakdown test. My compression was 158psi before 2mm HKS blew. I was hoping this 2mm Cometic would seal. I have a stock head gasket, might be more torque and less boost for a while. Thanks