320 Degrees! How high is too high?
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,928
Likes: 8,030
From: poway
Your HT (which is not a hard number, but an algorithm derived number) dropped because you were stopped, no longer putting a load on the engine. Even without the fans, that HT number will drop when you come to a stop.
I'll give that a try.
One more question/comment. My oil temps generally run 220 - 240. At the same time I am seeing ET on my PV at 230 - 260 and HT on my PV at 320 -330. Are you saying that the actual temperature of the sending unit screwed into the front head is what is being reported as ET on the PV?
Yes.
How can that sending unit's temperature be the same or similar to the oil temperature that I'm seeing?
See explanation below-
I would think it would be much hotter since it is screwed into the hottest part of the engine?
I would think the temperature of the head sending unit would be the actual HT and the PV would report such as HT. Then the ECM does whatever it does with "load and algorithms and what not" to report a calculated ET. I cannot believe my oil temperature measured in the oil pan is the same or very close to the sending unit temperature in the head. What do you think?
One more question/comment. My oil temps generally run 220 - 240. At the same time I am seeing ET on my PV at 230 - 260 and HT on my PV at 320 -330. Are you saying that the actual temperature of the sending unit screwed into the front head is what is being reported as ET on the PV?
Yes.
How can that sending unit's temperature be the same or similar to the oil temperature that I'm seeing?
See explanation below-
I would think it would be much hotter since it is screwed into the hottest part of the engine?
I would think the temperature of the head sending unit would be the actual HT and the PV would report such as HT. Then the ECM does whatever it does with "load and algorithms and what not" to report a calculated ET. I cannot believe my oil temperature measured in the oil pan is the same or very close to the sending unit temperature in the head. What do you think?
Regarding your question above of "How can that sending unit's temperature be the same or similar to the oil temperature that I'm seeing?"
One of the main ways the Twin Cam is designed to cool, is by squirting oil on the underside of the pistons. This is done to cool the pistons, but it transfers that heat to the oil. The pistons are subject to intense combustion heat, and then the oil is subject to that same heat.
Since your cylinder and heads have fins to help dissipate the heat, and the main area where the oil resides has no easy way to dissipate the heat (unless you have an oil cooler)...PLUS you have fans to cool your head further...it is normal, and expected, that once your bike is fully warmed up, that the oil will be hotter than the cylinder heads.
On air cooled Twin Cams and M8's, once the engine is fully warmed up, it is not unusual to see the oil as hot, or hotter, than the head temperature sensor.
Our goal, with a variety of cooling strategies, is to get the head temp sensor and the oil to Both be around 230* while going down the road at highway speeds on a hot day.
Important thing to note is that, except for the air cooled M8, there is no oil circulating thru the heads, and very little circulating thru the Rocker Boxes on top of the heads. So cooling the heads has little effect on oil temps.
All the above is specifically about the air cooled Twin Cams and M8's. The Twin-Cooled Twin Cams and M8's behave a bit differently, since they have liquid cooling for the heads and no oil cooler.
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Cruiser
Joined: Mar 2014
Posts: 101
Likes: 2
From: Maryland
Found some info from someone who apparently knows more than the average poster in here:
There are several temp related channels within the Delphi ECM. The most common channel used is Engine Temperature which is based directly off the 0-5V signal from the ET sensor on the front cylinder head, this channel is reported on the databus as ET. Generally speaking when we speak of engine temp we refer to the data from this channel, we usually consider 240-320F about the normal range relative to conditions, engine mods, and other variables. The second channel is Head Temperature which this is a bit more complex, it is a model the ECM calculates based on the ET sensor, the intake air temp (IAT) and other factors. Head Temp is used within the ECM primarily for Spark Temp correction, for most combination it will run between 260-400F. Note: Heat Temp has been recently added to the PV channel list an is reported as HeadT. The last channel is Coolant Temp which is active on twin cooled and V Rod applications. Hope this info helps... (Fuelmoto)
As oleboy would say, it's a little confusing, because Head temp is a misnomer, in the sense that it is not from the Cylinder Head, Engine Temp is, as far as PV is concerned.
So, if the temp reported by Dakota Digital is the CHT, then 320 would fall in normal range.
There are several temp related channels within the Delphi ECM. The most common channel used is Engine Temperature which is based directly off the 0-5V signal from the ET sensor on the front cylinder head, this channel is reported on the databus as ET. Generally speaking when we speak of engine temp we refer to the data from this channel, we usually consider 240-320F about the normal range relative to conditions, engine mods, and other variables. The second channel is Head Temperature which this is a bit more complex, it is a model the ECM calculates based on the ET sensor, the intake air temp (IAT) and other factors. Head Temp is used within the ECM primarily for Spark Temp correction, for most combination it will run between 260-400F. Note: Heat Temp has been recently added to the PV channel list an is reported as HeadT. The last channel is Coolant Temp which is active on twin cooled and V Rod applications. Hope this info helps... (Fuelmoto)
As oleboy would say, it's a little confusing, because Head temp is a misnomer, in the sense that it is not from the Cylinder Head, Engine Temp is, as far as PV is concerned.
So, if the temp reported by Dakota Digital is the CHT, then 320 would fall in normal range.
6th Gear
Joined: Jul 2017
Posts: 10
Likes: 0
From: Peoria, Az
I was wondering about this myself. Im not sure what my temps are running at but im new to HD and only had this bike for a couple weeks.
I live here in Phoenix, Az. Summers hit 120+ degrees here down on the road and have been wondering if its getting too hot. I put a 2.5 lift on the tank and it is tuned with a stage 1. Once in a while I can smell the heat coming off the jugs. I know its getting hot. I keep the RPM low and if I have to sit still more then 2-3 min I have been shutting it down until i can go. I don't know if that an overkill or causing harm in anyway? One thing I noticed too when you buy a vehicle you see them everywhere! I got this DWG and see no HD on the road. It might be too hot. Come on December to get cooler weather!!
I live here in Phoenix, Az. Summers hit 120+ degrees here down on the road and have been wondering if its getting too hot. I put a 2.5 lift on the tank and it is tuned with a stage 1. Once in a while I can smell the heat coming off the jugs. I know its getting hot. I keep the RPM low and if I have to sit still more then 2-3 min I have been shutting it down until i can go. I don't know if that an overkill or causing harm in anyway? One thing I noticed too when you buy a vehicle you see them everywhere! I got this DWG and see no HD on the road. It might be too hot. Come on December to get cooler weather!!
HD EFI Guru
Joined: Jan 2008
Posts: 4,492
Likes: 4,776
Where to start here. There is so much BS posted in this thread it's not funny, people do not really have a clue as to what it is really doing and why.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,928
Likes: 8,030
From: poway
Where to start here. There is so much BS posted in this thread it's not funny, people do not really have a clue as to what it is really doing and why.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
Road Warrior
Joined: Jul 2013
Posts: 1,725
Likes: 193
From: South
Where to start here. There is so much BS posted in this thread it's not funny, people do not really have a clue as to what it is really doing and why.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
The temperature sensor located in the front cylinder head on a Twin Cam engine is reading Engine Temperature, nothing more, nothing less. Normal operating range on a TC is 320 or less. HD does not even think 320 is too hot! One of the test we use to run was to ride the bike and pull it into a small tented area and leave it running. ALL wind or air movement was blocked by the tent so the bike just sat and ran. I have seen temperature well over 400 degree's and the engine just kept right on running just fine! I sure would not be sitting on it, but they run none the less without damage.
So remember it is an air cooled engine and it will run hot with little to no air movement around it and those saying damage will occur are pretty much feeding you all a line. Yes, high oil temperature hurts the oil's ability to lubricate and it best to change it if you've got it really hot. High oil temperatures are once the oil is above 270 NOT when the engine temperature is at or above 270.
The ECM has models built in the code that uses several sensor inputs (not just ET) to arrive at Head Temperature on a Twin Cam engine. These models were arrive from mounting real sensors on the engine, then testing. Once the models output and the measurements were done there is no longer a need for the extra sensors. This saves $$$ and works fine, provided you do not modify the engine to cause these models to become incorrect. Head temperature is use for a lot more than spark corrections too. It is a part of all fuel calculations and more.
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
But since most of the BS came from Mad HeadBlow we will let it pass.
Keep postin
Last edited by OddJack; Aug 13, 2017 at 04:27 PM.
Extreme HDF Member
Joined: Feb 2015
Posts: 10,907
Likes: 8,758
From: Galt's Gulch - MI
Where to start here. There is so much BS posted in this thread it's not funny, people do not really have a clue as to what it is really doing and why.
::: snip :::
Kewl; a reasoned response
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
::: snip :::
Yea, HD said that for ages; people have short memories
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
::: snip :::
Kewl; a reasoned response
For the record the hottest part of the engine is the combustion chamber in the cylinder head. Since it is the hottest, cooling it down also cools the engine the fastest, bar none! Oil collects heat from the engine cylinder head and lucubrates the engine. Reducing the hottest part of the engine that the oil comes in contact with will reduce oil temperature too.
The rear cylinder shut down or EITMS as HD calls it was only done for rider comfort!
::: snip :::
Yea, HD said that for ages; people have short memories
This is what I've done for the past 40+ years of my life, and I spent over 12 of those years doing it for the motor company, so I do know it very well.
Yea, OK, we all get it; you're a goram Jedi Master. Funny thing though, how you conveniently left out the actual ****ing solution here. Not actually a surprise, though.
Reducing the hottest part of the engine; now, how do us mere sad unwashed mortals, clueless posters, serfs, and retards actually do that?
Fans? Oil coolers? Better tuning? Magic pixie fairy dust? Hope and prayer? OR just use some hyperbole to make it all better?
Curious
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Extreme HDF Member
Joined: Feb 2015
Posts: 10,907
Likes: 8,758
From: Galt's Gulch - MI
Dick...
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,928
Likes: 8,030
From: poway
My guess is that you didn't pass reading comprehension.. My dyslexia occasionally catches up with me but you were the one saying the temp sensor in the head was for the head temp.. I been saying all along it's engine temp. CHT readings are calculated from engine temp (read from the sensor in the head) and engine loading.