M8 Engine Temps
HDF Community Team
Joined: Oct 2018
Posts: 4,347
Likes: 3,392
From: Seattle
I keep an eye on the temps pretty much only when in traffic and lane splitting so I can know if the engine is getting too hot, but anywhere else I kinda dont bother keeping tabs on it.
As for engine oil longevity, I ride enough that I can just change it at interval, and its probably gonna be just fine.
When DK puts out their M8 softail radiator fan assist thing, I'll be adding that to my bike and It'll probably be the solution I need to not need to worry about temps when traffic decides to clog up mercer and i5.
As for engine oil longevity, I ride enough that I can just change it at interval, and its probably gonna be just fine.
When DK puts out their M8 softail radiator fan assist thing, I'll be adding that to my bike and It'll probably be the solution I need to not need to worry about temps when traffic decides to clog up mercer and i5.
Road Warrior
Joined: Nov 2022
Posts: 1,541
Likes: 543
From: MN
good Lord man this is just one of your many comments on the subject...
"It's not just for saving oil and oil changes, it's for engine longevity. For those who say there's no difference, did you ever check your output power level running hot all the time? There is a difference. "
I looked up fussing in the dictionary and it said See Also; Old New rider
carry on, OCD analysis paralysis is free entertainment for me so please continue with your testing and reporting
"It's not just for saving oil and oil changes, it's for engine longevity. For those who say there's no difference, did you ever check your output power level running hot all the time? There is a difference. "
I looked up fussing in the dictionary and it said See Also; Old New rider
carry on, OCD analysis paralysis is free entertainment for me so please continue with your testing and reporting
HDF Community Team
Joined: Oct 2018
Posts: 4,347
Likes: 3,392
From: Seattle
Road Warrior
Joined: Nov 2022
Posts: 1,541
Likes: 543
From: MN
Interesting - why the big spread between 200F to 290+F? If outside temp varies by 30F, like here? It was 77F when I ran 200F oil. Way cool running engine.
Road Captain
Joined: Sep 2013
Posts: 575
Likes: 190
From: USA
good Lord man this is just one of your many comments on the subject...
"It's not just for saving oil and oil changes, it's for engine longevity. For those who say there's no difference, did you ever check your output power level running hot all the time? There is a difference. "
I looked up fussing in the dictionary and it said See Also; Old New rider
carry on, OCD analysis paralysis is free entertainment for me so please continue with your testing and reporting
"It's not just for saving oil and oil changes, it's for engine longevity. For those who say there's no difference, did you ever check your output power level running hot all the time? There is a difference. "
I looked up fussing in the dictionary and it said See Also; Old New rider
carry on, OCD analysis paralysis is free entertainment for me so please continue with your testing and reporting
Stellar HDF Member
Joined: Apr 2012
Posts: 3,117
Likes: 1,193
From: Maryland
Apples and Oranges. Oil Temps vs. Engine Temps (ET) reported on the PV. Oil temps range 200F to 210F. ET noted... "during the summer can run anywhere between 270F to 310F - but on warmer days, it's typically in the 280s, maybe low 290s."
Road Warrior
Joined: Nov 2022
Posts: 1,541
Likes: 543
From: MN
Surprised how wide the temp spread is between oil and metal. Maybe the M8 added oil cooler and head oiling makes a huge difference compared to previous engine models. Sounds like M8 should last longer.
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Stellar HDF Member
Joined: Apr 2012
Posts: 3,117
Likes: 1,193
From: Maryland
The M8 temp sensor is on the front of the rear cylinder head. IIRC TC's temp sensor is on the back of the front cylinder head (why TC's tend to read lower ETs than M8s). The EVO Sportster temp sensor is on top of the rear head. Because of this, Sporty's commonly run with ETs in the 370s to 410s. No matter where it's located, temps around the cylinder heads are going to be considerably warmer than oil temps.
M8 being my first Harley, the oil cooled heads must help a lot compared to previous air cooled heads.
Do you have catted mufflers? Those suckers get hot, but the engine doesn't heat my legs too much.
I noticed this summer the EITMS system has only come on once this summer with cooing fans installed, compared to multiple times last summer without cooling fans. This summer so far has 24 days of 90+ F compared to 20 days last summer and 13 day summer average. And more 90F days coming this week. I don't know what rear head temp setting the EITMS comes on at. Have also read the system doesn't do a lot to keep engine temp down. II left it on, doesn't seem to hurt anything.
Do you have catted mufflers? Those suckers get hot, but the engine doesn't heat my legs too much.
I noticed this summer the EITMS system has only come on once this summer with cooing fans installed, compared to multiple times last summer without cooling fans. This summer so far has 24 days of 90+ F compared to 20 days last summer and 13 day summer average. And more 90F days coming this week. I don't know what rear head temp setting the EITMS comes on at. Have also read the system doesn't do a lot to keep engine temp down. II left it on, doesn't seem to hurt anything.