E Glide Rig: Closed muffler - risk to overheat engine?
56t-bird
Posted 4/17/2016 4:58 AM (#88734)
Subject: E Glide Rig: Closed muffler - risk to overheat engine?



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Location: Zurich, Switzerland
Up to now I had Screaming Eagle SE mufflers on my 2004 E Glide Classic side car setup - I bought it this way 2nd hand. These tubes are entirely open, even in the USA allowed on race tracks only as it is engraved on the muffler wall. No wonder they are extremely loud when turning the throttle up - I like to avoid because of the silly noise but nevertheless have (and like) to do it now and then. Last summer in hot Spain the first time I had problems with irregular running engine @ 2000 rpm. Seems to be a known HD problem. But unlike most tips on the web (EFI, gas filter) my (superb) mechanic suggested it might be the low compression coming with the open tubes that after 30,000 miles burnt away the last hinderance in the tubes themselves. He suggested to add a chicane in the mufflers. I let it as is, since I knew I would soon have to submit to a state tech inspection where even the chicaned SE mufflers would not pass. I did it successfully last week with standard HD mufflers that I received separately together with the 2nd hand bike. Strikingly, the acceleration is noticeable better (higher compression?), the irregularities @2000 rpm gone (at spring temps, however), and last but not least, noise at acceptable level. I thought everything's sweet now, but the mechanic advised me to still put the chicaned SE mufflers on because of the risk of overheating the engine and eventually destroy it, given the enhanced compression with standard closed mufflers, the extra side car load, and mountain passes I gonna ride. Is this really a concern ? (I should mention there is an oil cooler attached).
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Hack'n
Posted 4/17/2016 2:17 PM (#88737 - in reply to #88734)
Subject: Re: E Glide Rig: Closed muffler - risk to overheat engine?



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A less restricted exhaust will expel heat more readily than a restricted one. Your catalytic convertor already restricts the exhaust and causes higher engine temperatures.
The compression ratio will remain the same.
The differences in performance may be due to having a more balanced intake and exhaust ratio.
Most SE equipped Harleys also have a less restricted air filter along with the SE mufflers.
Too much spark advance will also cause overheating and poor performance.
2 stroke motors require certain exhaust restriction to perform at their best, but a restricted exhaust decreases power with a 4 stroke motor.

Lonnie
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56t-bird
Posted 4/18/2016 2:18 AM (#88743 - in reply to #88737)
Subject: Re: E Glide Rig: Closed muffler - risk to overheat engine?



Member

Posts: 40
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Location: Zurich, Switzerland
Good points, Lonnie. Yes, it's about heat flow in open vs standard tubes regarding overheating engine. Given the much better acceleration with standard tubes - the only fact right now - the setup appears to be better balanced and I leave it this way. Carefully watching for signs of overheating. I count on HD engineering anyway, since standard tubes were standard heat management in the first place, and with added oil cooler it should really be fine.
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bluehdmc
Posted 4/18/2016 4:09 PM (#88749 - in reply to #88734)
Subject: Re: E Glide Rig: Closed muffler - risk to overheat engine?


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I have a 2004 Electra Glide (not a Screaming Eagle though), I think catalytic converters were only on California models. Your performance problem may be caused if the ECM wasn't programmed correctly for your open exhaust. Most dealers in the US and some aftermarket shops can program the ECM. I had a friend who put aftermarket mufflers on her softail and it use to stall out and run rough until her mechanic got it set up properly.
Harley Davidson also made a parade fan kit for touring models, and there's also "Love Jugs" and some other models at J&P cycles that help cool the engine. The Harley kit relocates the horn to under the fairing which I don't care for. There isn't much room there and it makes the horn a little harder to hear.
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56t-bird
Posted 4/18/2016 4:43 PM (#88751 - in reply to #88734)
Subject: Re: E Glide Rig: Closed muffler - risk to overheat engine?



Member

Posts: 40
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Location: Zurich, Switzerland
Thanks for this hint. Yes, I guess I have a non-cat muffler, bike is from Florida. I agree, the ECM is very likely standard or "messed up" and thus not compatible anymore with SE setup. The better acceleration with standard slip ons is one hint. In the long run I gonna set back to standard anyhow, don't need a screaming rig, and prefer more torque over power not going fast on the highway.
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IndSlim
Posted 4/20/2016 1:28 PM (#88760 - in reply to #88751)
Subject: Re: E Glide Rig: Closed muffler - risk to overheat engine?


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The "compression" you refer to is actually the back pressure needed to avoid exhaust pulse reversion. Not all exhaust systems are created equal, and the loss of torque with open pipes is well known. HD motors are restricted by EPA regulations, and respond well to well balanced changes to intake and exhaust. Having fuel injection means that the ECM must be adjusted to recognize the changes. There are aftermarket units that will adjust fuel and timing such as the Power Commander. One vendor, Fuel Moto, will even ship you a PC with a preloaded map for your particular bike. You will get more power and your motor will run cooler.
All this info is available online, and some time researching will be worth it.
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