BSA B50 -500 APG Build

[wobblywalrus]

A hobby shop that specializes in radio control model airplanes has all the little connectors you need.

[Koncretekid]

Thanks Dennis, Peter, and Bo,
As far as hobby shops in this area I am S.O.L.  I was able to identify the connectors as Molex Micro-Fit 3.0™ 43025 and they and the contacts are available from Digi-Key.  However, the crimping tool is $130 and the removal tool (in case of mistakes) is another $30 which puts them a little out of the ballpark.  Unless I can find an enduser out there with the tools to make up the short connectors I need, I'll just have to use the 4 foot ones available from Innovate.

I had some nice 2" thin wall aluminum tubing to hook up to my airbox, but it didn't like to bend smoothly in an exhaust tube bending machine which put two small kinks on the inside of the bends, even with only 10 degree bends.  I'll try them anyway as a starting point.  I misspoke myself a few posts ago when I said I expected a 1 psi increase in inlet pressure at 160 mph.  Upon further research I can only find that it will increase the pressure by .45 psi for only about 2 hp increase, and that's only if the intakes work properly.  I probably won't bother with them at Loring, but may try some runs with and without them at Bonneville.

Following are photos of the new gauge layout (lights are on but nobody's home yet) and the new intake tubes.  The right intake tube aligns perfectly with the inlet in the fairing, but the hole is only 1-1/2" ABS.  On the left side, the intake does not line up so I'm going to have to cut out the old one and glass in a new one.  Ideally, the 1-1/2" should gradually open up to the 2", but I might just go with new 2" inlets for now.  Being around 30" long, I'm going to get some line loss anyway.  I can easily change back to 1-1/2" with a tapered tube if it doesn't work.

Has anybody been able to verify an improvement with ducted intakes?

[tauruck]

The gauges look great.

Be positive about the inlets man.

[Old Scrambler]

Positive air-flow at any rate sure beats negative

Mr. Mellor seems to do quite well with his oval-shaped front intake leading to a square-ish tube molded into his fairing. 

[Koncretekid]

Yes, I have seen Tom M's intake snorkel.  He of course, goes faster than me, and the dynamic pressure boost that he gets is proportional to the square of the speed. I'll bet that intake also increases in area at it approaches his airbox at a rate not exceeding 7 degrees; just a guess.  Tom's experience in the aircraft industry has paid off.  When I was building my bike, I had a photo of his bike on my wall.

[Old Scrambler]

The 200-mph Trident has a square-ish air tube below the carbs that I estimate to be double that of the cross-section area at the current oval-shaped intake. I got a really good look at it in 2009 when I was helping him change the jets on the 750cc motor and the snorkel was smaller and less obvious.   

[WOODY@DDLLC]

I would step the tubes - 1.5", 2", 2.5".  Make the lengths 5 X the diameter and radius or taper the back steps. This will get you an area expansion of 2.77 and a velocity reduction of nearly 2/3rds. You are trying to turn the air 180° and the air won't really like it. Slower air is easier to turn. I would try a large conical K&N to smooth the ugly air before it goes into the carb. Had to take a quick look, so here is a teaser or two .........

[Koncretekid]

Thanks, Woody,
I will be using 1-1/2" entry with a tapered transition at 7 degrees out to 2", but I can't increase the size any further due to space constrictions.  Also, the length to the first transition is at about 5X the 1-1/2", but from there to the airbox is about 24".
Tom

[Tofu]

In chapter 7 of John Robinson's book "Motorcycle Tuning - Chassis" he talks about air intakes to feed carbs etc. "they should not add to the frontal area or spoil its shape, and they should be of the smallest size necessary to provide the required air flow. If they are too big they will cause extra drag for no benefit in power. The flow losses in the pipes depend upon the dimensions of the pipes. They are proportional to the length and inversely proportional to the area.
For a 90 degree bend the radius of the bend should not be tighter than 6 x the diameter of the pipe in order to keep the losses acceptably small. A corrugated pipe tends to behave like a plain pipe of considerably smaller diameter.
Section changes in the pipe should also be gradual. In general a diffuser should have an included angle of no more than 15 degrees. Sudden steps will cause turbulence and will generally reduce the flow capacity of the pipe.
The pipe and its intakes should be matched to the air requirements of the engine although the flow in the pipe will vary with the bikes speed. For high speed operation, smaller pipes will deliver the required air flow for the minimum of drag
The amount of air needed depends upon the speed and the effective area of the scoop – which will be somewhat less than the geometric area if the pipe is not smooth and straight.
If the effective area is A (feet² or m²) the speed is v (ft/s or m/s) and the air density is d (lbf/ft³ or kg/m³) then the weight of the air is W.  W=Avd.
Assuming the an air density of 0.08lbf³  (1.29kg/m³) and typical air flow rates/power levels for various speeds, then the area of the scoop needed is shown in the table. One column just matches the engine’s air flow need at maximum speed, the other matches its need at 100ft/s. if the scoop is larger than required then it adds to the drag of the bike and is obviously more difficult to install. If the scoop presurises the air box at high speed then the carbs should be vented to the air box and carburation checked at various speeds”.
Engine air flow v. road speed

Max speed ft/s      Air flow needed lbf/h       scoop area for max speed                   scoop area for 100ft/s           176                               420                              1.18 sq/in                                    2.1 sq/in           198                                600                              1.5                                                 3.0           220                                 840                              1.9                                                 4.2           242                                 1020                              2.09                                            5.1           257                                 1200                              2.32                                            6.0

I dont know if this of any assistance but I thought that it addressed some issues.

[Koncretekid]

Thanks, Tofu,
I generally used John Bradley's book for reference, and I have sufficient area for my motor at my predicted speed, but of course, a 12" radius inlet would be difficult.  The inlets tubes are actually adjacent to my knees, and the whole bike is only about 20" wide of which the frame is 9" outside, so 5-1/2" from the frame to the fairing, including my knees!  There is one transition from 1-1/2" from 2" at an included angle of about 15 degrees.  I'm just finishing the bodywork around the inlets, so I'll give it a try.
Tom

[wobblywalrus]

The front tip of the fairing is a good place for a hole that will not mess up up the aero.

[Koncretekid]

I returned home to Nova Scotia with a long to-do list including rebuilding stuff after the harsh winter we had.  And then there was hurricane Arthur...............

I finally got around to trying to start the new 600cc 14 to 1 CR motor, but the old starting rollers struggled to turn it over.  I got it started (with two batteries and jumpers from my van), but new gauges just shut off.  Anyway, rebuilding the starter took precedence.  I added a second Dodge reduction gear starter - - now it turns over and starts.  But after about a half hour of running, I removed the sump to find bits of steel on the screen.  Took apart the right side of the motor and disassembled the oil pump to find nothing.  Took apart the top end of the motor and found that the new pushrods fouled on the rocker arms and broke chunks off of the tops of both.

The new Innovate gauges boot up and look nice before the motor actually starts.  But then they just shut down.  I rebuilt the dash using sheet steel to shield them from the coil wires, but the same thing happened again.  I removed the wire to my Scitsu tach which uses induction pick-up from a coil wire, and the gauges started to read.  So it looks like I can have AFR and data logging (maybe) or a good tachometer, but not both. 

The following photos show the new MEGA starter, bits of steel from the sump, and the broken pushrods.  So now with just 6 days till Loring, I'm waiting for new pushrods.  I will try to post some photos of converting a Dodge reduction gear starter for use on rollers in the tech section.

[saltwheels262]

tom,
for some reason my motor  always need 24 volts going through the starter.
whether it is a Mopar gear reduction or onboard Harley type.

I have a new in the box Mopar big case starter. call me if you need it , I will bring it to
caribou.
Fred and I are leaving Tuesday at the crack and plan on being there Thursday morning.
Diane can not make the trip but she is doing fine and in remission.

bf262

[Koncretekid]

Bill,
Thanks for the offer but the new twin starter motor rollers turn the motor over fine even on 12 volts.  The big issue now is that I don't have any pushrods and with the efficiency of the Canadian Mail, I might not get them in time.

Here is a link to a video I made of the start. Quality of the upload is not good but still required all morning!

https://www.youtube.com/watch?v=MJw7qvS-Kiw&feature=youtu.be

Tom

[Rasmussen]

Now, that is one healthy sounding beast 
Didn't get a single word of what you were saying after firing up the engine though

Why new pushrods?