Old ham can air cleaner fit new premiers?
- Thread starter Joe Schlaberdowski
- Start date
- Status
- Joined
- Dec 28, 2008
- Messages
- 2,035
Up to about 20 years ago I didn’t give air cleaners/boxes much thought and often considered velocity stacks for my street bikes while knowing that unfiltered air would hasten wear in the cylinders, but figuring that the high side loads the guides were bearing would be the gating factor in renewing the top end, but always defaulted to using some form of intake filtration with the exception of the Colin-Seeley Trident I built for the ’71 AAMRR season.
My eldest son purchased a CBR 900 RR when he returned from Desert Storm with the 82nd Airborne. He wanted a “pipe” and asked me about it, I advised him to buy the parts as a sorted kit from a vendor that could support him.
Cutting to the chase, the kit came with 2 sets (8) of main jets where the 2 inner carbs got different sizes than the outer carbs; I was sure that he had picked a vendor that was “substance distracted”, so I called them. The bottom line was that Honda had spent a lot of R & D money coming up with the shape and volume of the airbox to insure that turbulence and resonance were minimized/eliminated and that air flow was consistent (where they wanted it), but also determined that size limitations for the airbox required the 2 outer carbs to be jetted differently than the 2 inner carbs. Airboxes became “rocket science” for me after that.
You can, virtually, solve these short comings with turbocharging or supercharging, but given British motorcycles’ propensity to morph into something that looks more like a device that you pull a pin from and throw at your enemy when configured to make much more HP, and being broke in my early days, the Drouin “solution” was well beyond my means and made me think that such a power adder was like riding my Norton with the “pin” already in my pocket; I'm aware that a few forum members have them and have had positive experiences, but are they really using the capability? More power usually means less reliability; it's one thing to use some of the design margins manufacturers build into their engine designs, but I don't think there is much margin built into an air cooled British twin. Reminds me of an old friend that one said to me: "Bill, I was born with nothing and I still have most of it left".
I believe that “Ram Air” was more of a marketing strategy, especially after reading, years ago, an article written by Kevin Cameron which, essentially, stated that the benefit was very small and that at some loads/RPMs actually caused a loss of power.
Looking at the “ham can” filter assembly, since then, has caused me to wonder if much thought had been put into its design. More than a few posts on this forum have heralded the Mk3 “football” as being one of the best updated design features. But, does it matter? Are we taking about wringing another 1 or 2 HP with a better filter design, or is the pot of gold at the end of this rainbow more bountiful? I sure don’t know, but would be interested to hear from anyone who has done some serious work in this area, or who could point me to any previous posts on the subject.
Best.
My eldest son purchased a CBR 900 RR when he returned from Desert Storm with the 82nd Airborne. He wanted a “pipe” and asked me about it, I advised him to buy the parts as a sorted kit from a vendor that could support him.
Cutting to the chase, the kit came with 2 sets (8) of main jets where the 2 inner carbs got different sizes than the outer carbs; I was sure that he had picked a vendor that was “substance distracted”, so I called them. The bottom line was that Honda had spent a lot of R & D money coming up with the shape and volume of the airbox to insure that turbulence and resonance were minimized/eliminated and that air flow was consistent (where they wanted it), but also determined that size limitations for the airbox required the 2 outer carbs to be jetted differently than the 2 inner carbs. Airboxes became “rocket science” for me after that.
You can, virtually, solve these short comings with turbocharging or supercharging, but given British motorcycles’ propensity to morph into something that looks more like a device that you pull a pin from and throw at your enemy when configured to make much more HP, and being broke in my early days, the Drouin “solution” was well beyond my means and made me think that such a power adder was like riding my Norton with the “pin” already in my pocket; I'm aware that a few forum members have them and have had positive experiences, but are they really using the capability? More power usually means less reliability; it's one thing to use some of the design margins manufacturers build into their engine designs, but I don't think there is much margin built into an air cooled British twin. Reminds me of an old friend that one said to me: "Bill, I was born with nothing and I still have most of it left".
I believe that “Ram Air” was more of a marketing strategy, especially after reading, years ago, an article written by Kevin Cameron which, essentially, stated that the benefit was very small and that at some loads/RPMs actually caused a loss of power.
Looking at the “ham can” filter assembly, since then, has caused me to wonder if much thought had been put into its design. More than a few posts on this forum have heralded the Mk3 “football” as being one of the best updated design features. But, does it matter? Are we taking about wringing another 1 or 2 HP with a better filter design, or is the pot of gold at the end of this rainbow more bountiful? I sure don’t know, but would be interested to hear from anyone who has done some serious work in this area, or who could point me to any previous posts on the subject.
Best.
This will not work until about 55-60mph. I have done a funnel on the front of several bikes with a half inch bore heater hose to the carb bell mouth, every time I got a slight boost in power at 60 mph, I've also done the same to fuel injection diesel Van's and got the same result.
Last edited:
Onder
VIP MEMBER
- Joined
- May 11, 2010
- Messages
- 4,286
A lot of the airbox design is to keep water out. I know my 73 Trident with the fully perforated surround was replaced by one with a
unperforated top and then one with two holes at the bottom. Now Im sure some of this was about EPA noise regs but the original one
can get soaked in a downpour.
Of course riding in the rain was for my youthful days!
unperforated top and then one with two holes at the bottom. Now Im sure some of this was about EPA noise regs but the original one
can get soaked in a downpour.
Of course riding in the rain was for my youthful days!
- Status
