Triumphrat

redhawk34 · 12-25-2008, 02:09 PM

I was taught to vote the straight Republican ticket, to keep my weapon clean, and to always have some inlet tract upstream of the carb.
Unfortunately, when removing the Thrux airbox and installing the K&Ns, which does significantly reduce inlet resistance, you also reduce that upstream tract to zip. When the tract is too short, you can actually burp air/fuel mix out of the carb mouth. A longer tract (inlet bellmouth to inlet valve) also increases the length (and therefore mass) of the entrained airflow, which reduces the inlet pressure pulse amplitude. Think of it as a Slinky. Longer is better, UP TO A POINT!
Couldn't find stacks for the CVKs, so I made a set, complete fabrication instructions are on the 1st pic.

The bellmouth is kept small (which makes less difference than you might think) so that the stacks will fit into K&N pancake filters. Obviously, the stack ID matches that of the carb intake.
http://www.knfilters.com/search/prod...x?Prod=RC-1900
This is a test fit, the mounting setscrews in the skirt aren't installed yet.

I used solid bar stock, because I had solid bar stock, but I watched the boring bar go back and forth for hours.
McMaster Carr has 6061T6 tube by
the foot, with wall thickness up to .5".
http://www.mcmaster.com/
Type the following page # in the search box, scroll down.
3544
Redhawk
(Y'all pundits, I know it ain't gonna work, will rob 30 HP, and will result in blueing of the passenger footpegs. So humor me.)

rodburner · 12-25-2008, 02:24 PM

Nice!

mikeinva · 12-25-2008, 02:38 PM

pretty work but hope you are not going to run them everyday on the street,motors dont like dirt.I dont know how much they will help you .you going to dyno it ? from the testing i have done I am not sure you will gain much over no filter on these bikes .If you are running the little k&n type pod filters you may see some gain because they dont let air flow in a stright line out the back of the carb like some filters do.I think if you want to play with how long the intake tract is you should be doing it on the other side of the carb.I dont know its hard to say what works till you try it.

redhawk34 · 12-25-2008, 03:16 PM

Oh, I'll be running filters. There are better ways to bore out the cylinders to 1000cc than by ingesting sand.
http://www.knfilters.com/search/prod...x?Prod=RC-1900
They look small, but the math works out. I agree, deleting the filters doesn't gain you much. They fit right on the end of the stacks.
There's a huge divergence of opinion on inlet tract length (translation; a lot of it is BS), but there seems to be consensus that the overall length of the tract is important, as all that entrained air has mass, and therefore inertia. Whatever you do with it, you have to consider it all.
I have already matched the ports to the phenolic blocks and to the inlet monofolds, and have replaced the rubber carb mounts with machined ally rings, so I have smooth sewer pipe from carb to inlet valve (but for the turbulators.) I can't do much more there, so I'm trying to improve the other end.
We've had icing, so I haven't ridden it yet, and I don't expect 20 HP, or even 2HP. We'll see. If I added up all the claimed HP figures on my add-ons, I'd have 100 HP at the rear wheel.
On a side note, it's been decades since I read Ricardo, so I went looking for a used copy. Well, Sir Harry is selling for hundreds of dollars USED!
Best,
Redhawk
Is "monofold" a word?

rodburner · 12-25-2008, 03:26 PM

Quote:

Originally Posted by redhawk34

Is "monofold" a word?

As it pertains to the Bonnie,I say YES.

robnobrakes · 12-25-2008, 04:47 PM

Quote:

Originally Posted by redhawk34

Oh, I'll be running filters. There are better ways to bore out the cylinders to 1000cc than by ingesting sand.
http://www.knfilters.com/search/prod...x?Prod=RC-1900
I agree, deleting the filters doesn't gain you much. They fit right on the end of the stacks.

Replacing K&N's with 2.5" (65mm) long velocity stacks on my FCR's gained 2bhp at the rear wheel. I ran the motor for about 3000 miles before it was stripped for big valves and high lift camshafts, with absolutely no signs of wear to the valves, valve seats, camshaft lobs or cylinder bores.

However, I have now fitted Ramair (similar to Unifilters) foam filters for prolonged engine protection.

redhawk34 · 12-25-2008, 09:00 PM

Nice installation, you and I must have done similar sums, my stacks are 2 3/4" effective length.
Unlike in England, our ground dries out occasionally, which in the Peoples' Republic of Noo Joisey means sand. Throw in a little wind, and you have airborne sand, nice hard silicon oxide which will grind away carbide.
I came through Chelmsford the last time I was in England, lovely town. My Bride and Cousin went shopping up and down the high street, while I sat in front of McDonalds drinking coffee, smoking, and listening to imaginary cash registers. Shall we just say that those two did their best to improve Britain's balance of trade.
Best,
Redhawk

robnobrakes · 12-26-2008, 03:46 AM

Quote:

Originally Posted by redhawk34

I came through Chelmsford the last time I was in England, lovely town. My Bride and Cousin went shopping up and down the high street, while I sat in front of McDonalds drinking coffee, smoking, and listening to imaginary cash registers. Shall we just say that those two did their best to improve Britain's balance of trade.
Best,
Redhawk

Hi Redhawk

Can you come back and encourage you wife and cousin to hand out some more cash to our poor shop keepers LOL. Recession, what recession!!!!

redhawk34 · 12-26-2008, 04:32 PM

Final installation, with K&N filter;

Seems quicker from mid-throttle on up, but, then, I'm not a complete stranger to self-deception.
(If a placebo works, is it still a placebo?)
Best,
Redhawk

mikeinva · 12-26-2008, 04:52 PM

what kinda lathe you got redhawk?