Can you reuse an OEM Factory Nissan cylinder head gasket just torqued down but the engine was not started?

Hi so you will need a new head gasket now you have squashed the other one.

That is very iffy. I would go ahead and replace it to avoid another possible tear down.

There is no re-torque on head gaskets. Sorry.

Put a new gasket. It will not break the bank.

If you reuse it give it an extra 5 lbs. of torque.

Make sure you blow out the bolt holes in the block so you don't hydrolock the bolts and end up with a leaking head gasket.

MLS gasket. Multiple Layer Steel. You could search for that.

The multiple torque steps flatten out the gasket and then you stretch the bolts tight. The bolts are typically trash after used regardless of running engine. The bolts are torque to yield fastener. Even when used for applications where they will never get hot the same rules apply. I tested TTY reuse on heads years ago when they were new to cars (on my own car not a customers). Did the whole job perfectly except reused bolts. 20,000 miles and had combustion gases in radiator, got away with it for a little over a year. Worth it, NO. I've done similar tests with other gaskets including old style material head gaskets with varied results. I have never done this with MLS. I have read it does not matter: "However, head gaskets used for engine mockup can be reused, no problem." Here is a source, a trusted trade magazine: http://www.enginebuildermag.com/2017/10/mls-gasket...

I would buy the gasket and bolts for a customer's car. I might test it on my own car.

With the head gasket costing about 50 dollars and the work to get into where it is at being about four hours, just replace the gasket!

If the adhesives are still in the unfused state- then yes it can be re-used. But not all gasket makers use a thermal activated adhesive.

I am lazy on this (or cheap)- I just would hate to either have to take the engine apart again because the gasket should have been replaced or worse pay some mechanic one hundred dollars an hour because it gave out in a land far far away from my garage.

I wouldn't but that's just me. I never owned a Nissan. You should join a Nissan forum and ask there. These forums are great things - people who have owned this particular type of car for decades and have done every conceivable type of work and know all the tricks. It shouldn't be difficult to find one. It's not like Nissans are rare cars. Heck, there is a forum for DeSoto owners.