FYI, it is a 2000 Civic EX with D16y8 head and D16y5 block.

I got tired of manually tensioning the alternator belt alone, so I made this thinger from scraps and an eye-bolt from Tractor Supply. As you can see, I bench-tested the strength and then added some angled aluminum to reinforce the steel bracket.

Used:
- eye-bolt for 150lbs.
- fiber reinforced fuel line.
- silicon tubing for mounting eye-bolt to alternator.
- metric 10mmx1.5 bolt for mounting eye-bolt to alternator.
- extra washers.
- used copper crush washers around fuel line to brace bracket.
- zinc-dipped grade nut for eye-bolt.
- grade 10 nylon lock-nut.
- angle aluminum.
- Mobile1 synthetic grease for the tube and fuel line.

Untensioned on bench:


Tensioned on bench:


Installed on car, without belt:






Parts used:




Angle aluminum installed for extra support:




Remember, this tensioner is only used to enable the initial tension. Then tighten the mounting bolts to hold the tension. This device isn't really intended to support the belt tension long-term.