Sexy bell mouths, place your bets...
- Thread starter Fast Eddie
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- Jan 2, 2013
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Re: Hobot video:
The inlet of a turbojet engine is not a good comparison to a carby. The turbojet inlet must work from Mach zero to 0.86, and from sea level to 40,000 ft., and it's main function is to SLOW the incoming air without inducing wall separation. it seems illogical to intentionally slow the incoming mass but the combustors will sonic choke if the inlet speed to the combustors exceeds about M = 0.3.
Re: Effect of screens and filters
We engineers have always used an area reduction factor of 50% whenever screens, filters, or vanes are present in a duct system, even if the obstruction does not physically take up 50% of the area. This reduction is in part to account for the boundary layer buildup on the parts in the air stream. To minimize the flow restriction, the maximum filter area should be employed.
I have run my Atlas with only velocity stacks for 85K miles with no ill effects, mostly because the Atlas filter assembly is a PITA to remove for cleaning, and of little benefit except for removing leaves and small rocks. There have been times when I killed the engine and coasted to the side of the road to allow blowing dirt to dissipate.
One just cannot have it both ways .... Maximum power and guaranteed clean air.... Take your pick.
Slick
The inlet of a turbojet engine is not a good comparison to a carby. The turbojet inlet must work from Mach zero to 0.86, and from sea level to 40,000 ft., and it's main function is to SLOW the incoming air without inducing wall separation. it seems illogical to intentionally slow the incoming mass but the combustors will sonic choke if the inlet speed to the combustors exceeds about M = 0.3.
Re: Effect of screens and filters
We engineers have always used an area reduction factor of 50% whenever screens, filters, or vanes are present in a duct system, even if the obstruction does not physically take up 50% of the area. This reduction is in part to account for the boundary layer buildup on the parts in the air stream. To minimize the flow restriction, the maximum filter area should be employed.
I have run my Atlas with only velocity stacks for 85K miles with no ill effects, mostly because the Atlas filter assembly is a PITA to remove for cleaning, and of little benefit except for removing leaves and small rocks. There have been times when I killed the engine and coasted to the side of the road to allow blowing dirt to dissipate.
One just cannot have it both ways .... Maximum power and guaranteed clean air.... Take your pick.
Slick
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- Oct 19, 2005
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- 18,978
Ugh yoose number value brainiacs juggling flows and sonic pulses w temp & pressure equations is reason I quit chemistry and physics though parents said it was the P!! dragster distracting me form homework so ordered to sell it. P!! had dual Amals on factory manifolds and two open headers about 30 inches long. Appreciate detail of air craft jet intakes more arranged to trade velocity for pressure yet thats what we want to happen in the chambers so confounded me again. If not for the P!! power and then Peels handling I would of gone into modern cycles for thrills. Much as road racing is main thing on this forum minds - its the last thing on mine - especially after seeing hearing and feeling the power planting of George Kelly mostly factory 850 that spanked a couple 920s built similar to Kenny Cummings with JSM upgrades and an over bored XR900 built to National level spec$.
Take in this proven exception to the rules, single 38mm Miki carb, short-ish manifold, real filter for the horrendous rooster tail jets and two narrow-ish 30 inch-ish headers. Likely go even quicker if dropping those ape hanger handlebars.
Take in this proven exception to the rules, single 38mm Miki carb, short-ish manifold, real filter for the horrendous rooster tail jets and two narrow-ish 30 inch-ish headers. Likely go even quicker if dropping those ape hanger handlebars.
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- Nov 6, 2008
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eddie,they look great and probably perform even better,but the old bill will not be impressed if they see the race only stickers on the carbs lolFast Eddie said:I'll be playing with different exhausts on the Dyno soon, but the first run will be with no other changes except fitting the super sexy bell mouths shown below in place of the K&N filters and adapters as supplied by CNW.
Place your bets now as to what the BHP increase will be...
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- Feb 10, 2009
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Cops don't look at carburettors.
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- Nov 6, 2008
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- 502
they will look for anything they can to give you a ticket,as a biker you should know thatTriton Thrasher said:
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- Oct 19, 2005
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Unless a road block dunk test stop ya 1st gotta get a cops attention and usually thats enough for the fuzz not to think of bike inspection unless the pilot is a jerk or the pigs want to plant drugs or a gun to meet their pay roll quotas. Could put a piece of tape over warning label for peace of mind. I run non DOT semi-bald ie: race slick tires on my SuVee and been stopped even towed off a few times but they did not bother me about the tires, sheeze. Bad ass looking carbs as ever fitted to Commandos.
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