Heat Management and the Screaming-Hot 110ci Screaming Eagle Engine

Screen Shot 2016-07-27 at 7.50.56 PMThere’s only been one real complaint I have with the two 2013 Harley-Davidson FLHRSE5 / Road King CVO’s we’ve owned (thus far atleast) and it the engine heat.

Let me say that when I first heard about Harley owners filing a class action lawsuit against Harley for heat-related injuries I was still riding our 96” motor Dyna and like a lot of folks scoffed at the notion. However, since then and having lived with two CVO Harley fitted with the 110 cubic inch “Screamin Eagle” motors I now have a profound understanding of the basis for their complaint.

Unfortunately, it’s a physics issue that can only be resolved by using modern technology, you know… water cooling, developed before the first air-cooled Harley-Davidson. Seriously, you do have to wonder about (a) Harley’s product managers, (b) their power plant engineering team and of course (c) consumers like myself who have buried our heads in the sand while continuing to buy and ride air-cooled V-Twin motors that generate exhaust manifold temperatures in the upper 400F degree range and oil temperatures that tickle 300F.

Mind you, these are on bikes fitted with Harley’s factory spec oil cooler. Moreover, these engine temperatures were recorded on both of our 110” engine-equipped Road Kings AFTER several things were done to reduce the engine heat!!!

In regard to the latter, here’s what I’ve done to date that has influenced the engine heat we must deal when riding these machines:

  1. Removed the stock exhaust system and replaced it with a ceramic-coated, free-flowing head pipe, larger diameter cross-over pipe and mufflers.
  2. Had the engine professionally tuned by a Harley-Davidson Dyno Expert to optimize the air fuel mixture and reduce the lean-running condition that also contributes to engine heat.
  3. 20151122_181443Made the mistake of adding finned cosmetic cylinder head / spark plug covers to the top of the motor which, in all likelihood, reduced engine cooling efficiency instead of improving it.
    1. These covers have since been removed and a reduction in engine oil temperature has since been observed!
  4. Added heat deflectors to the frame above the rear cylinder’s exhaust manifold / pipe.
  5. Removed the entire “movable door” from each of the lower fairings to increase air flow past the engine in the warmer months when keeping the body and engine warm is not a problem.
  6. 479158214_tpInstalled a digital oil temperature gauge / oil level indicator dip stick so that I can more easily monitor the engine oil temperatures. Why every Harley doesn’t come with an oil temperature gauge is a mystery to me.

Yet, despite it all, the engine still routinely runs with the oil temperature hovering around 270F on hot days here in Georgia. Mind you, that’s not while sitting stuck in traffic… that’s measured after coming to a stop after riding at normal engine and vehicle speeds.

There are still a few things than folks have done to reduce engine heat that I’ve elected to pass on; they include:

  1. Installing a 6 quart oil pan in place of the stock 5 quart pan. While I think this might lower the oil temperature on shorter rides with mild temperatures, it wouldn’t do much to reduce the oil temperature under the extreme conditions and, frankly, that’s where it’s needed.
  2. Screen Shot 2016-07-27 at 8.09.56 PMInstalling a pair of fans that pull air against the top of the engine cylinders triggered by a thermal switch set to 175F. While the little fans look like they are designed and built well, I’m just not ready for what seems like a kludged-together work around to a poorly designed power plant with inadequate cooling.
  3. Screen Shot 2016-07-27 at 8.15.25 PMInstalling an aftermarket oil cooler / heat exchanger in place of Harley’s OEM oil cooler that also incorporates a pair of cooling fans for idle condition that purportedly increases the amount of heat being extracted from the oil. This seems like it could be a pretty good upgrade, unfortunately I don’t think they worked the product integration all that well as the things look like a bolt-on afterthought.
  4. Adding a pair of fans to Harley’s OEM oil cooler to increase the amount of heat being extracted from the oil when the bike isn’t moving. This seems like it might help a little when stuck in traffic, but it’s a band-aid on the OEM oil cooler which – if these do work – should already have fans.
  5. Adding a three stage oil cooler that is installed under the oil pan that significantly increases the amount of heat being extracted from the oil. Having seen this design I’d be worried about damage from road debris and/or tearing the thing up when loading the motorcycle on a trailer: it’s very much exposed below the protection of the frame.

To say that I’d welcome a water-cooled option that is more than a bolt-on cylinder head and that cools the entire cylinder would be an understatement. I don’t need more horsepower or torque, what I need is an engine that runs 60F – 100F cooler than the one I have right now! 20160630_143629And, to that end, I’ve paid a lot of attention the touring bikes fitted with the 103” and 110” “water head” purchased by our friends over the past two years. Sadly, these bikes have had a lot of teething pains and were something of Beta Test models for the early adopters. Setting aside the various recalls and warranty repairs to these “Rushmore” bikes, including issues with the water cooling system, most of the folks report a very noticeable reduction in engine heat.

Screen Shot 2016-07-27 at 8.22.07 PMAnyway, we still like everything else about our Road King CVO, to include having only the reduced size windscreen. I sometimes think about adding a removable Dragonfly fairing as a way of (a) providing us with a little more wind protection at freeway speeds or during cooler temps and (b) making the bike look a little more grown-up / full-on touring spec. with the iconic batwing. However, I don’t need any additional audio or GPS capability and without those the inner fairings begin to look a bit ridiculous. However, the bigger issue is, the times I’ve ridden a batwing Harley I’ve felt like I was sitting behind the wheel of a 1950’s MG TD instead of being on a motorcycle.

Time will tell what we do, but at the moment we’re not doing anything! Other than doing our best to stay cool when that damn engine is running hot!


About TG

I've been around a bit and done a few things, have a couple kids and a few grandkids. I tend to be curmudgeonly, matter-of-fact and not predisposed to self-serving chit-chat. Thankfully, my wife's as nice as can be otherwise we'd have no friends. My interests are somewhat eclectic, but whose aren't?
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One Response to Heat Management and the Screaming-Hot 110ci Screaming Eagle Engine

  1. jim Wright says:

    I totally agree , my 2011 cvo convertable is a great bike but it runs way too hot!!!!

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