Oil temp
Outstanding HDF Member
Joined: Nov 2008
Posts: 2,034
Likes: 127
I don't consider high temps in a Harley V-Twin until it hits 300 degrees +.
The rear cylinder dropout, which is found on certain late model Harleys does not come into play until 278 degrees. It initiates only when the bike is not moving at idle engine speed. If the engine somehow hit 300 degrees or more (and they all will) it does not disintegrate nor does it render itself inoperative. When you hit temps in that range, you need to get moving. High temperatures is where the use of synthetic oils in an air cooled engine really shine in comparison to dino oils. If a person does not want to go with the high cost of multi weight synthetic oils an alternative would be a high quality multi weight heavy duty diesel oil such as Delo or Shell 15W40.
I recently checked my oil temperatue after coming in from a 2 hour ride at 70-75 mph. The ambient air temp outside was 78 degrees and my oil temp was 246 degrees. As long as you have air blowing across those jugs (cylinders) and fins, high temps are just not a problem. If at some point you are seeing white smoke come off your fins, that is too hot and the engine needs to be shut off and allowed to cool down. The only time I have ever seen that is if the bike is in a parade or in heavy stop and go traffic when the temps outside are 100 degrees. If your bike is too hot it will tell you by being unresponsive to acceleration and really loud pinging.
The rear cylinder dropout, which is found on certain late model Harleys does not come into play until 278 degrees. It initiates only when the bike is not moving at idle engine speed. If the engine somehow hit 300 degrees or more (and they all will) it does not disintegrate nor does it render itself inoperative. When you hit temps in that range, you need to get moving. High temperatures is where the use of synthetic oils in an air cooled engine really shine in comparison to dino oils. If a person does not want to go with the high cost of multi weight synthetic oils an alternative would be a high quality multi weight heavy duty diesel oil such as Delo or Shell 15W40.
I recently checked my oil temperatue after coming in from a 2 hour ride at 70-75 mph. The ambient air temp outside was 78 degrees and my oil temp was 246 degrees. As long as you have air blowing across those jugs (cylinders) and fins, high temps are just not a problem. If at some point you are seeing white smoke come off your fins, that is too hot and the engine needs to be shut off and allowed to cool down. The only time I have ever seen that is if the bike is in a parade or in heavy stop and go traffic when the temps outside are 100 degrees. If your bike is too hot it will tell you by being unresponsive to acceleration and really loud pinging.
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
Sorry guys the CAT does not influence oil temp.
The EPA tune is what it is just like every new car on the road, its not overly lean, its just stoich in the cruise range (clean, responsive, and efficient), since it takes a ridiculous amount of enrichment to effect CHTs, ergo oil temp, I don't consider it a variable in manipulating oil temp, it has to burn fuel, thats what makes it an engine. Enrichment cools EGTs so the hottest element of the bike, the exhaust pipes, "feels" cooler when add a little fuel, there is no real drop in CHT/OT till you get the cruise A/F down in the low 13s and below.
As far as the OEM oil cooler on the 103s, I'm not so sure about HDs reasoning, but I would have to think the increased displacement and I think a lot of folks would agree the 96s could have used the OEM cooler a long time ago, and the 88s couldve benefitted also.
Account Retired
Joined: Oct 2009
Posts: 3,245
Likes: 12
From: Here
I think the main reason you see oil cooler's on 103's are due to Cat's in the header's and nancy boyz crying my motorcycle is hot. Man up, they are all hot. you are sitting on top of an engine with no insulation between you. I don't care what you put on them, when you stop you are going to feel heat, even if it's hot air blowing on you from the row of fan's you hung on it. Use a good synthetic oil and change it more often if you ride around town.
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Road Captain
Joined: Feb 2012
Posts: 525
Likes: 1
From: Oklahoma
I think the main reason you see oil cooler's on 103's are due to Cat's in the header's and nancy boyz crying my motorcycle is hot. Man up, they are all hot. you are sitting on top of an engine with no insulation between you. I don't care what you put on them, when you stop you are going to feel heat, even if it's hot air blowing on you from the row of fan's you hung on it. Use a good synthetic oil and change it more often if you ride around town.
Account Retired
Joined: Oct 2009
Posts: 3,245
Likes: 12
From: Here
the higher RPMs you turn the hotter your oil will get. MPH or Speed, this ones a little tricky, basically the slower you go the hotter your oil will get, because there isnt enough air to take the heat away from the cooling fins. There is also a point when you go faster than about 60MPH that your oil starts getting hotter also, more so because of the RPMs required to generate the speed also generate more heat than the fins can shed by natural air flow convection. I consider the RPMs the most influential, in steady state operations like cruising nonstop on a long road, I have witnessed that an increase of 250 RPMs will raise your normalized OT about 10 degrees, recently in some mild weather, about 75 I think, my OT normalized at 190F turning 2500 RPMS, I bumped it up to 2750 RPMS and it gradually came up and leveled off at 200F, bumped it again to 3000 RPMS and it came up to 210, 3250 on the superslab and it comes up to 220F.
This is some amazing **** right here!!! Who would have thought if you pull more load or stop, your oil will get hotter??? I would suggest if you didn't already know this, sell your bike and sit on the porch so you won't hurt yourself.
This is some amazing **** right here!!! Who would have thought if you pull more load or stop, your oil will get hotter??? I would suggest if you didn't already know this, sell your bike and sit on the porch so you won't hurt yourself.
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
The EPA tune is what it is just like every new car on the road, its not overly lean, its just stoich in the cruise range (clean, responsive, and efficient), since it takes a ridiculous amount of enrichment to effect CHTs, ergo oil temp, I don't consider it a variable in manipulating oil temp, it has to burn fuel, thats what makes it an engine. Enrichment cools EGTs so the hottest element of the bike, the exhaust pipes, "feels" cooler when add a little fuel, there is no real drop in CHT/OT till you get the cruise A/F down in the low 13s and below.
Further, when I was running a PCV I was able to toggle between a relatively rich and lean map (13.5 vs. 14.6 in the cruise range) and only saw a 7° difference in CHT on a summer highway ride--no difference in OT based on the gauge reading.
I think AFR is misunderstood as being a panacea for lowering engine temperatures, but this isn't my experience. I run nearly stock AFRs at all times and don't have a heat problem--only rarely seeing CHT hit 300° in heavy traffic.
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Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
the higher RPMs you turn the hotter your oil will get. MPH or Speed, this ones a little tricky, basically the slower you go the hotter your oil will get, because there isnt enough air to take the heat away from the cooling fins. There is also a point when you go faster than about 60MPH that your oil starts getting hotter also, more so because of the RPMs required to generate the speed also generate more heat than the fins can shed by natural air flow convection. I consider the RPMs the most influential, in steady state operations like cruising nonstop on a long road, I have witnessed that an increase of 250 RPMs will raise your normalized OT about 10 degrees, recently in some mild weather, about 75 I think, my OT normalized at 190F turning 2500 RPMS, I bumped it up to 2750 RPMS and it gradually came up and leveled off at 200F, bumped it again to 3000 RPMS and it came up to 210, 3250 on the superslab and it comes up to 220F.
This is some amazing **** right here!!! Who would have thought if you pull more load or stop, your oil will get hotter??? I would suggest if you didn't already know this, sell your bike and sit on the porch so you won't hurt yourself.
This is some amazing **** right here!!! Who would have thought if you pull more load or stop, your oil will get hotter??? I would suggest if you didn't already know this, sell your bike and sit on the porch so you won't hurt yourself.
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