I run all my gear in the HVAC room. It's the only unfinished portion of the basement. I never had any issues.

If your ambient temperature is that close to your operating temperature, you're going to have to pass a hilarious amount of air across the machine to keep it within range. So don't do it unless you're going to blow fans directly at it that are controlled by internal thermostat or are always moving air fast enough.

Not that this is hard. One 6"inline duct blower could do this if you cowl it right.

My home server is located in our boiler room which sees similar temps. No problems, and the drive temps aren't too bad.

Provide it with conditioned air for intake, but in the cooling season route the exhaust to your furnace's air return, to contribute toward heating the house.

I'd consider insulating the ductwork and doing air sealing if it gets that hot, as it means lot of your heat is not making it where it should so your hvac is probably running more than it needs to.

Bad idea. Hard drives hate heat

86 isn't very hot, mines in my garage and in the summer it gets close to 110 in there. Servers, nas and network gear all fine and it's been 4 years.