J-series is an easy assumption as the head shape/design is so similar from the top. OP didn't post a year, so I had to stare at it a moment before I figured out it was a C-series, but I'm not terribly familiar with the RL. Giveaways were the plug wells (cast not tubes) and it's lacking V-TEC which is present in all Acuras equipped with J-series engines if I'm not mistaken.
Yeah, I've often wondered what's wrong with a little varnish? Note I said 'a little' not enough to clog anything. Seems like it would be harmless and might even protect against corrosion.