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A similar sort of thing was fitted to the old Rover cars.

They were petal shaped, and named after one of the pioneers of fluid dynamics - Bernulli of something similar.

They must obstruct flow - the Rover motor was a 2-2200 inlet over exhaust slug knocking out 60/75 HP, but in had twin 2" SUs which were good for 150 HP more on a clear inlet tract.

When jetted up to Healy 3000 settings the 50 mm SUs made a Datsun L28 / 280 Z motor fly, but I didnt try them with the vanes/petals below them.

Unclviny wrote:MS,
If I put 10 of those on either side I'll get 100% fuel economy increase?!, where did I put that Credit Card!

Vince

In reality, there is a very effective way to get a 100% fuel economy increase and it costs nothing. On either side of the fuel tank there is a little lever. Turn both until they are horizontal. Leave them in that position... Job Done!

Rob

Rob Frankham wrote:In reality, there is a very effective way to get a 100% fuel economy increase and it costs nothing. On either side of the fuel tank there is a little lever. Turn both until they are horizontal. Leave them in that position... Job Done!

Rob

Hmmm. Would that be zero miles per gallon since you're not consuming any or would it be an infinite amout, since you'll have the same amount of gas no matter how many miles you go.

Well, there is something that no one has mentioned so far...

You can squeeze a little more HP out of your engine by delivering more cold air, so I experimented with the idea of drilling more holes in my air cleaner and stater cover like this:



Of course, I left the stock air cleaner in place and it did increase intake roar quite a bit but my "Butt Dyno" said that the cold air helped a little. The The R90 engine ran very well, especially off the bottom but it's very easy to mistake greater noise for better performance.

The reverse scoop in the starter cover, acts as a vent for heat under the front cover, so my presumption is, that at least some of that heated air ends up flowing into the air box but truth be told, I have no idea how those things actually interact with one another.

I am currently installing a new late model clutch in the R100 and then I'm going to modify a square air box to fit under the /6 tank and run that combo first with the Bing 40's and Supertrapps and then with with the Delorto's. Several people have opined that the square boxes are worth up to 2 extra HP. In the end, I don't much care which air-box I use, as long as the engine is happy and isn't particularly finicky.

KenHawk wrote: Of course, I left the stock air cleaner in place and it did increase intake roar quite a bit but my "Butt Dyno" said that the cold air helped a little. The The R90 engine ran very well, especially off the bottom but it's very easy to mistake greater noise for better performance.

the roar from the intake is really loud! I have the stock drilled round air box with mikuni tm38's. You can hear them from the sidewalk. I'm interested in the flat intake myself. What modification have to be made to a '77 engine to have it bolt on? I saw a older BMW with intake snorkels that ran to the front of the motor like a modern superbike. It did look neat but is it practical?

KenHawk wrote:You can squeeze a little more HP out of your engine by delivering more cold air, so I experimented with the idea of drilling more holes in my air cleaner and stater cover like this:

maybe I could rig up some way to have a piece of dry ice outside my intake to cool the air and a pump to spray a cool mist in, too.

twist wrote:

KenHawk wrote: I saw a older BMW with intake snorkels that ran to the front of the motor like a modern superbike. It did look neat but is it practical?

For drawing in cold air, it makes some difference. I don't know if it would be very measurable, but there is certainly a theoretical improvement. Oilheads use a snorkel to draw cool air in from the front for just that reason.

As far as "ram air," like current Superbikes use, complete waste of time.
1) they have to do a fair amount of wind-tunnel testing to find the proper place to locate ram air intakes.
2) They are only effective over about 150 mph.

Major Softie wrote: As far as "ram air," like current Superbikes use, complete waste of time.
1) they have to do a fair amount of wind-tunnel testing to find the proper place to locate ram air intakes.
2) They are only effective over about 150 mph.

that sounds right. In the 70's all the hot rods had that ram air or cowl induction but it seemed to me that it didn't do much unless there was a high volume of air and it seemed to me that you had to be moving a lot faster than was legal to get the benefit. All the cool stuff really isn't that useful, eh? Things devised for the track really don't transition well to the street. But they look cool and make it look fast!

twist wrote: I'm interested in the flat intake myself. What modification have to be made to a '77 engine to have it bolt on?

Just get the parts: Starter cover, air-box cover, filter, and plumbing.

twist wrote:I saw a older BMW with intake snorkels that ran to the front of the motor like a modern superbike. It did look neat but is it practical?

Without objective testing, such experiments will typically be "neat" – if nothing more.
Forced-air Induction will be much more complicated than simply facing the intake forward ...

Likewise, Re: "butt dyno" –
Typically, these dynos can always be counted upon
to provide the anticipated if anecdotal and unproven response.
The "butt dyno" is best suited as a medicated salve
to ease the cost of investment/expense, time and/or money,
regardless of any real-world change in performance.

in the end I have to wonder if it's worth the time and expense to make that change. what are the benefits to cost? I do like the square box look but the round box isn't bad either. I want function over form. Spending money for the sake of something "new" doesn't make sense. If it works why change it? If there's an improvement to be had is it enough to justify money spent?!