Years back had twin Mikuni 29 smoothbores on a Shovel , much more compact than the units you show.
Probably an extinct set-up today

 

Actually that is one thing I missed and it's very informative.. I have external air bleeds on both my E and G.. thanks..

 

BTW 2 30mm holes are not equivalent to a 60 mm hole. Its the area that equates to flow. 2 30s are roughly the same as 1 43mm carb.

 

Yes, you're absolutely right; I was being overly simplistic. I did research and bench flow studies when designing the combo ram pipe and snorkel adapter for my blow-through supercharger conversion, and there's a lot of drag associated with the edge of the hole, turbulence, etc., that would need to be taken into account. That, as well as easier plumbing and cost considerations (for end users) was why I settled on a single HIF44 for the A-Series application. That said, there is a lot of controversy among British car enthusiasts about your point, and endless multi vs. single carb debates. I stepped away from those, made a simple flow box (which I gave to a local community college auto shop class), and pretty quickly tossed out the idea of pressurizing dual carbs.

But they are sexy, would be unique in this application, and engineering challenges are just plain fun, IMHO. I'll likely run the Super E once dialed in for high desert riding for the near-term future, then snag a 40mm CV setup when I get ready to do some interstate touring.

Question: which (CV vs. Super E) would be easier to swap jets (or needles) on the road as needed if the tour dropped closer to sea level?

 

You know, I vaguely remember Ron (the outlaw biker--real, not a poser) from whom I bought the flathead describing the Mikuni he'd fitted as a smoothbore. This was in the late '70s, so would that be more likely back then? It was a single carb, though. I'm positive about that.

 

Decided to rebuild the shift lever bushing, as there's too much slop and I'd like it to shift perfectly. Was out in the garage when the dog alerted just around the corner in the entryway courtyard from his perch inside the French doors. This is what had him a bit perturbed...

It wasn't huge, only about three feet or a bit longer, but the thing must've cruised right by where I was tinkering away, slithered down the path and into the courtyard. Luckily, the wife had hung out the laundry and went back inside...

 

Yeah about the only thing I need to worry about up here in the Northeast is raccoons and skunks the rest pretty much leave you alone we don't get snakes like that rare.. and don't put your boots outside at night scorpions like them as well...

 

Rattlesnake
Screw that !

 

Yeah, the wife wouldn't let me dispatch it, as they keep the pack rats and mice down to a dull roar. But this is the second time in two successive summers I've had 'visits' from these guys. Last time, I had a car up on the Quick Jacks to do some work, and a 4-footer came into the garage, glided past my steel toe boot (I was trapped between the scissors and couldn't get away), checked out each corner of the space, then went on its way.

Here's a photo of a non-venomous visitor I found one morning during the build last summer.

Never a dull moment here in the high desert...

 

So, these S&S cylinder head castings are great--triple valve springs, high quality valves, large and clean ports, etc. However, the bike suddenly lost power and, after limping home, I determined that the intermittent miss I had early on, and which I'd initially attributed to a slightly lean mixture, had blossomed into the rear cylinder barely firing at all.

I did a leak down test and sure enough, the exhaust valve was leaking. I knew it hadn't burned because the AFR is a touch on the rich side at this altitude with the standard Super E recommended jetting (even with the shotgun pipes and shorty Sportster mufflers).

I then pulled and disassembled the head, and it looks like the valve and seat were physically damaged during assembly. Perhaps by a metal chip or keeper or something else getting clamped in there by those powerful springs. It must've either been expelled by the tech--who then did not do a sealing test on the bench--or by the exhaust pulse when I fired up the bike. No way I would've heard something that small clink out through the pipe with these loud mufflers.

Anyway, I've asked PowerSports Superstore (least expensive retailer of these heads that I could find) how they want to resolve the issue. I can't recall the S&S warranty terms, but I hope they or the retailer will do the right thing. We'll see...

BTW - check out the lousy work done on the sealing surfaces, probably with a worn, gouged cutter. Compare to the fourth pic, which is my typical hand-cut seats...



Dent or chip out of valve tulip

Corresponding dent in seat--which I have to say has lousy sealing surfaces in general

Compare with a burned exhaust valve from a racing engine that had a cracked intake manifold