Ideas to pretty this up?

You’re right!  I have a similar pair and the finish is rough, at best.  You could take them locally to someone who does wheel or metal polishing to “Spiff” them up and polish them.

The outside of the cans almost look brushed (poorly) and should clean right up with 300-1,200 grit sandpaper, both the can and the tube - They’re both Aluminum and should then easily take a polish, once they are smoothed out with the paper.  

Polishing the top of the cans, with those ribs cast in, will take more work with a very narrow polishing disk.  Once polished properly, everything will look like jewelry (or like a similar chromed piece).  

Get them painted with ceramic chrome like they do with headers.  Or find someone with a milling machine. Use a 3/8" end mill and quickly cut off all the casting surface on the top and then buff it and the sides. Either way, they will look outstanding !..Bruce

Or wrinkle paint spray them.

I've polished rough aluminum but it takes a lot of elbow grease.  I've used WD sandpaper and those scotchbrite-looking balls that go on a drill.  It's actually pretty rewarding as just a couple of hours produce a big improvement - your hands will be black for weeks to get alum oxide off.

Not a huge fan of shiny. When I got my polished EMPI oil filler I soda blasted it, my generator stand, my fuel pump block-off, and my manifolds so they matched, then clear-coated them with Eastwoods Diamond Coat.

My air filter tops were older, and they have a much better finish than yours, so I left them.

If you want to polish yours, I’d seriously consider getting them glass or plastic media blasted to knock down some of those imperfections first, then take them someplace to get them polished.
When I restored my Ducati Scrambler, it cost less than $100 to have both the engine cases and both hubs polished and I’m sure it saved me 40-60 hours of sanding and polishing. (Not to mention whatever toxic nightmare having black hands for a month entails)

Polish would be an easy (though time consuming) diy. Emery cloth 120 then more emery 150, then 180 then 220. Then wire brush with a wheel and some sand paper through 400. Then the polishing wheel. I'd leave the spaces between the fins rough and paint them either engine or body color. Just mask the parts and paint the tops then use a block sander to take the paint off the tops of the fins. Polish that and maybe clear it and yowza! they'll pop.

While we’re on the subject, something I learned years ago on a BMW motorcycle forum:

Polishing aluminum reduces the surface area by 50% and subsequently affects the heat transfer. Not much of a worry with air cleaner housings, but still.  

@dlearl476 posted:

While we’re on the subject, something I learned years ago on a BMW motorcycle forum:

Polishing aluminum reduces the surface area by 50% and subsequently affects the heat transfer. Not much of a worry with air cleaner housings, but still.  

I've heard higher figures quoted.  The actual numbers don't really matter if you're counting on that surface to shed heat.

I had a rough aluminum casting and stumbled on a really nice finish that's low effort. I had the casting bead blasted, which gave it a satin/sparkly look, and then had it clear powder coated. It had the look of a fine metalic gray finish that wore like iron.

That sound interesting.

Fantastic advice, everyone >> Thank you!  I knew y'all would have some experiences to share to help me get my head around this.  😉

I've never been a fan of a chromed-up engine bay on any of my classic vehicles, but the Spyder came to me with a chrome fan shroud, along with chrome engine tins and carb filter housings.  So, while these new pressure caps don't need to be mirror-like, I would like to have them in the same reflective family as the rest of the shiny pieces.  If they weren't shiny, I'd probably paint them black or red to match the black chassis or the red accents in the interior and rear fender spears. 

So many great suggestions and details!  I've now got some game plans.  Thanks again, and I'll be sure to share back some pics when I decide on what path to take. 

On a related note, I performed a test fit on the driver's side yesterday evening with the caps and the filter cones attached.   I don't like the position of the cone, as it's up against the fan shroud one way, and when I turn it around the other way, the wheel well will hit it.  So, I'm going order this one (see attached photo) that should keep the cone free and clear of everything.  Any experiences among y'all against using this design, with its lower angle? 

That's the one I'm using.  There is a left and right version.  Looks like this (notice, I went with the ratty-casting look):

@Gordon Nichols posted:

That's the one I'm using.  There is a left and right version.  Looks like this (notice, I went with the ratty-casting look):

Thanks, Gordon.  Gonna order a pair of these.  😉

Don't forget the rubber base gasket.

And be advised, the aluminum turbo hats are shorter than the standard filters. If you have velocity stacks, be aware of the clearance.

@DannyP posted:

Don't forget the rubber base gasket.

And be advised, the aluminum turbo hats are shorter than the standard filters. If you have velocity stacks, be aware of the clearance.

That part drives me nuts. It wouldn't be difficult at all to add 3/4" to the height, and let the guys who need them shorter cut them off.

@Wulfrik (John) posted:

Any experiences among y'all against using this design, with its lower angle?

I've been running them for 3 or 4 years. Really quiets in the intake noise, and I no longer worry about a backfire catching my filter on fire and burning the car to the ground.

@DannyP posted:

Don't forget the rubber base gasket.

And be advised, the aluminum turbo hats are shorter than the standard filters. If you have velocity stacks, be aware of the clearance.

Yes, sir. Both have been ordered.  👍

I ordered new bases, too, as mine are single, centered screw.  

@Stan Galat posted:

I've been running them for 3 or 4 years. Really quiets in the intake noise, and I no longer worry about a backfire catching my filter on fire and burning the car to the ground.

Perfect — thanks, Stan.  

I've had mine on for a couple of years.   The noise drop from the intakes is noticeable - Maybe 25% - 30% or so?  Especially with the intakes/filters pointed towards the back.  

And as Stan mentioned - We no longer worry about rain getting in or setting the car on fire.  Always a good thing.

@Gordon Nichols posted:

I've had mine on for a couple of years.   The noise drop from the intakes is noticeable - Maybe 25% - 30% or so?  Especially with the intakes/filters pointed towards the back.  

And as Stan mentioned - We no longer worry about rain getting in or setting the car on fire.  Always a good thing.

Glad to hear, Gordon.  I'm hoping to drop the conversation volume in the cockpit just below screaming level. 

@Wulfrik (John) posted:

Glad to hear, Gordon.  I'm hoping to drop the conversation volume in the cockpit just below screaming level. 

I think the muffler adds the most to the sound of the car, I had a dual muffler set up on my original IM 2110cc and it was way more quieter than a lot of cars.  Just saying.

@IaM-Ray posted:

I think the muffler adds the most to the sound of the car, I had a dual muffler set up on my original IM 2110cc and it was way more quieter than a lot of cars.  Just saying.

Good Morning, Ray.

Well, I checked that box two months ago, changing the single-muffler setup to a two-muffler version from Carey.  It helped, but it wasn't the great difference that I was hoping for. 

Some great advice from this group gave evidence that pressure caps can cut the dB level in half, so that's what I'm trying next. 

I'll report back! 

Good that you did that I never knew about the caps at the time of my ownership of the  Aircooled IM so good to know and I hope it helps.

I understand the noise level is for some very acceptable

@IaM-Ray posted:

Good that you did that I never knew about the caps at the time of my ownership of the  Aircooled IM so good to know and I hope it helps.

I understand the noise level is for some very acceptable

Oh, I like a loud sound as much as the next guy!  However, if this modification can decrease the noise a bit so I can talk rather than scream when I've got my wife along for the ride, then that's a good tradeoff.  😉

Yes talking can be a challenge.

@Wulfrik (John) Don't pay any attention to Ray(on this issue).

Stan, Gordon, and I all confirmed major dB loss with the turbo hats.

Lol.  Your right Danny I have no experience with carb.  Hats