Question? Slip On

[Stealth128_imp]

Normally I would have to clean the pipes on my bike up from those nasty brown spots every couple hundred miles get out the Blue Magic Rub Rub Rub. But since I have installed the Two Brothers exhaust the pipes have remained pristine. I already know the bike runs a lot cooler. My question is that could the stock exhaust canister get that much hotter it was what was creating those dark spots on the header pipe. Also anybody that change the exhaust canister notice this also?

Thanks,
[attachment=1951]

 

[pechorin75_imp]

Can't really answer directly since I'm still running the stock muffler, but I have noticed that the rate at which my pipes "bronze" and develop spots has really decreased since the beginning of summer. I suppose it's possible I'm imagining this, but it sure seems like it happened a LOT faster back when I was riding in 50-60 degree temperatures.

 

[Lord Popgun]

Pechorin,

I thought it was just me! I've noticed the same thing, but I though it was just the engine getting/being broke in. Didn't think about outside air temps maybe having something to do with it.

 

[xNE0x_imp]

With mine being a 2014 black standard, the bronze looks good to me. Then again, I have weird tastes.

 

[The Spaceman_imp]

Stealth, I've been trying to figure out your feeling that your bike runs cooler with the 2Bros since you posted it in another thread. I'm not an engine design engineer or even an expert in thermodynamics, but a couple things about it bother me:

- Metal is a great heat sink and is also great at transferring heat to the air. That's why computer chips have the big fins on them, as do our bike engines. The CB's OEM can has a LOT more metal than the 2Bros, which has only a very thin skin, so if anything, I'd think it would pull more heat from the engine than the much smaller 2Bros can.

- When you open the exhaust with a free-flowing muffler, unless you change the fueling, the bike will run leaner. Leaner running means hotter running. Having said that, the CB was the first and only bike I put an aftermarket exhaust on that didn't need FI changes to run properly, but I would still think it ran leaner.

Why do you think the CB runs cooler with the 2Bros? Did you add a temp gauge, or have you checked with one of those laser sensors?

BTW: as much as I like my 2Bros exhaust, I didn't notice any difference in header discoloration between it and the OEM. My headers seem to get stained by water, as in running through puddles or in the rain.

 

[Stealth128_imp]

Spaceman,
I can answer this maybe more. First the exhaust flow as with your 2 Brothers exhaust is almost twice the velocity out compared to to the stock can. Measured with a ultrasonic Exhaust Flow Meter EXFM. Keeping it simple the exhaust blows out twice as fast carrying heat with it. Ok stand behind your Two Brothers at idle very noticeable increase in exhaust output from the stock system at idle. Makes sense the flow meter confirms this. Two Brothers dyno chart on You Tube confirms a nine horse power increase. Now for the heat I used a Black Decker Thermal Leak detector gun
TLD 100. If you don't own one of these I strongly recommend you buy it 27 dollars on Amazon. This tool is awesome you can measure temperature on you CB with spot on detail. Ok I Live in Florida and it is hotter then hell here! The BD shows a 24 degree drop with the Two Brothers compared to the stock can. I never touched the electronics or added anything the bike runs much better with no signs of being lean .
I'm thinking the oxygen sensor on board electronics adjusted for the new can. I have no popping on deceleration. You should have a increase in you system as well. Actually I'm impressed with the performance so far I have driven down the interstate at 85 and drove in heavy city traffic realizing perfect performance. Two Brothers chart shows a large increase in torque as well. IMO I think the stock system is way to restrictive to meet the from hell emission standards for Europe at the expense of creating heat while restricting the flow. Last but least the weigh drop I have not felt any difference in weight while driving but have when placing it on the center stand. Very happy with my header pipes they look awesome no spotting yes I drive in the everyday it rains here in the summer.
Thanks,
Stealth
Hope this helps explains my findings.

Stealth, I've been trying to figure out your feeling that your bike runs cooler with the 2Bros since you posted it in another thread. I'm not an engine design engineer or even an expert in thermodynamics, but a couple things about it bother me:

- Metal is a great heat sink and is also great at transferring heat to the air. That's why computer chips have the big fins on them, as do our bike engines. The CB's OEM can has a LOT more metal than the 2Bros, which has only a very thin skin, so if anything, I'd think it would pull more heat from the engine than the much smaller 2Bros can.

- When you open the exhaust with a free-flowing muffler, unless you change the fueling, the bike will run leaner. Leaner running means hotter running. Having said that, the CB was the first and only bike I put an aftermarket exhaust on that didn't need FI changes to run properly, but I would still think it ran leaner.

Why do you think the CB runs cooler with the 2Bros? Did you add a temp gauge, or have you checked with one of those laser sensors?

BTW: as much as I like my 2Bros exhaust, I didn't notice any difference in header discoloration between it and the OEM. My headers seem to get stained by water, as in running through puddles or in the rain.

 

[The Spaceman_imp]

Good reply Stealth, I'm glad you used a gauge to check the temp vs. "seat of the pants.". A 24 degree drop is good, was that with the bike stopped and idling?

I'm in FL too, (Ft. Lauderdale) and so far I haven't felt like the bike hhe approached overheating. I do shut the engine off if I'm out UN the heat of the day and I know I'm going to be sitting at a long traffic light.

The most significant temperature drop I ever got was on my Shovelhead HD. Switching from Dino oil to synthetic dropped 30-40 degrees as measured by my oil tank thermometer. With that big oil cooler and synthetic, I think my CB will be fine with either exhaust.

 

[ClassicVW_imp]

With the less restriction and the increased HP, does that come at a cost of somewhat decreased MPG?

 

[the Ferret]

Be interesting for him to shoot that DB heat sensor and the motor and in particular spark plug area and see what the readings are. Honda made a lot of effort with an oil gallery and finned cover around each of the spark plugs to try and cool that area down.

 

[Lord Popgun]

I've shot that area before and its HOT. I forget how hot, I'll have to check the next time I go for a ride.

Heck, the starter gets a lot hotter than I like to see electrical equipment get, but not a whole lot you can do about it. I just hope its designed for long term heat abuse!

 

[Stealth128_imp]

Good evening,
Spaceman I drove the bike 10.6 miles before checking temps 5.2 miles in city traffic light to light to and back from the interstate. 5.4 miles on the interstate 70 mph light
traffic temp 93 degrees humidity 82 percent. Upon my return I let the bike idle to stabilize for 2 min then checked the temperature with the B&D I did the same exact test with the stock can and the Two Brothers only diff was 120 mins between test as you know the exhaust is a simple 10 min install had to wait for the bike to cool down I wanted the motor to be the same for both runs or close to it. Also I use the
10w-30 Honda blessed GN oil and filter. Use 87 octane shell gasoline every thing-else on the bike is stock. Now because we both live in Florida you understand how hot the
pavement here is compared to other places. I don't know what effect that would have on this test or any at all. Perhaps we need to ship the B&D around to other members to use on this types of experiments and I wonder how much diff in the state of Washington running the same base specs will they have a gain or a loss?

Thanks hopes this helps.

Good reply Stealth, I'm glad you used a gauge to check the temp vs. "seat of the pants.". A 24 degree drop is good, was that with the bike stopped and idling?

I'm in FL too, (Ft. Lauderdale) and so far I haven't felt like the bike hhe approached overheating. I do shut the engine off if I'm out UN the heat of the day and I know I'm going to be sitting at a long traffic light.

The most significant temperature drop I ever got was on my Shovelhead HD. Switching from Dino oil to synthetic dropped 30-40 degrees as measured by my oil tank thermometer. With that big oil cooler and synthetic, I think my CB will be fine with either exhaust.

 

[StreetFighter_imp]

Normally I would have to clean the pipes on my bike up from those nasty brown spots every couple hundred miles get out the Blue Magic Rub Rub Rub. But since I have installed the Two Brothers exhaust the pipes have remained pristine. I already know the bike runs a lot cooler. My question is that could the stock exhaust canister get that much hotter it was what was creating those dark spots on the header pipe. Also anybody that change the exhaust canister notice this also?

Thanks,
[attachment=1951]

Which exhaust and which model CB1100 do you have? I bought the M2 Black series and the box only mentioned 2013 but, it mounted and had the center stand blocker as well.

I'm just curious as I want to make sure this thing really is for my bike and not some hack job that could have my chain bouncing off my center stand.

 

[Ferrealls_imp]

Streetfighter - I have the M-2 on my 2014 standard. Fits perfectly. Same mount setup as the 2013.

As for heating, yes, the more restrictive OEM muffler will cause the exhaust casing to be hotter than with a less restrictive muffler.

If you're curious about the reason for this, here's the breakdown. If you're not, disregard.
Conservation of mass in fluid dynamics is actually conservation of mass flow rate, and that tells us that when you reduce the cross sectional area of a pipe the flow must speed up. Thermodynamically, a fluid (i.e. hot exhaust gases) has a greater convective heat transfer coefficient at higher velocity. Long story short, faster exhaust gas through a smaller tube will result in more heat transferred to the casing.