ET in the Arizona Heat
Club Member
Joined: Dec 2014
Posts: 10,734
Likes: 3,755
From: SWFL
yeah, sure they put some thought and testing into it so it has merit, and the air cooled engines certainly warrant some attention in $tonecold's absolutely severe riding environment..but those ET temps even so, don't strike me as being a catastrophic failure waiting to happen, the engines have a protection mode and synthetic engine oil is developed exactly to handle those types of extreme temperatures
Last edited by Mchad; Jun 28, 2019 at 11:17 AM.
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,623
Likes: 11,355
From: State of Confusion
this was at the Pendleton, Or Rally, several hours before we got to Lewiston...I didn't look nearly as happy at the end of that day after almost going down from tar snakes and completely wiped out from the heat
Last edited by mjwebb; Jun 28, 2019 at 11:31 AM.
This morning the ambient temperature was 77 F. I rode 17 miles on city streets at 50 mph. The ET held at 279 F until the last 3/4 mile, which was pulling into work at 25 mph. The temperature rose to 284 during that 3/4 mile distance.
I am showing lower temperatures than Steve, but the conditions are somewhat different. The speed limit is 45 mph here and the distance between stoplights is longer. Stopping seems to facilitate temperature rise. Also, I am using synthetic oil and I am not sure Steve was when he was monitoring temperatures.
The Mighty Mite type fans dont direct an air stream on the TwinCam head temperature sensor like a center mounted fan would and the TwinCams also have a tunnel behind the spark plugs to give air better access to the heads, so the TwinCams might actually have cooled better with that type of dual fans system. The amount of cooling the oil did in TwinCams was negligible though. Since the M8 is actually oil cooled I think the best way to bring ETs down is by cooling the oil better. This has already been proven by the differences in Steves readings between no fan and fan installed.
I am showing lower temperatures than Steve, but the conditions are somewhat different. The speed limit is 45 mph here and the distance between stoplights is longer. Stopping seems to facilitate temperature rise. Also, I am using synthetic oil and I am not sure Steve was when he was monitoring temperatures.
The Mighty Mite type fans dont direct an air stream on the TwinCam head temperature sensor like a center mounted fan would and the TwinCams also have a tunnel behind the spark plugs to give air better access to the heads, so the TwinCams might actually have cooled better with that type of dual fans system. The amount of cooling the oil did in TwinCams was negligible though. Since the M8 is actually oil cooled I think the best way to bring ETs down is by cooling the oil better. This has already been proven by the differences in Steves readings between no fan and fan installed.
HD EFI Guru
Joined: Jan 2008
Posts: 4,462
Likes: 4,718
This morning the ambient temperature was 77 F. I rode 17 miles on city streets at 50 mph. The ET held at 279 F until the last 3/4 mile, which was pulling into work at 25 mph. The temperature rose to 284 during that 3/4 mile distance.
I am showing lower temperatures than Steve, but the conditions are somewhat different. The speed limit is 45 mph here and the distance between stoplights is longer. Stopping seems to facilitate temperature rise. Also, I am using synthetic oil and I am not sure Steve was when he was monitoring temperatures.
The Mighty Mite type fans dont direct an air stream on the TwinCam head temperature sensor like a center mounted fan would and the TwinCams also have a tunnel behind the spark plugs to give air better access to the heads, so the TwinCams might actually have cooled better with that type of dual fans system. The amount of cooling the oil did in TwinCams was negligible though. Since the M8 is actually oil cooled I think the best way to bring ETs down is by cooling the oil better. This has already been proven by the differences in Steves readings between no fan and fan installed.
I am showing lower temperatures than Steve, but the conditions are somewhat different. The speed limit is 45 mph here and the distance between stoplights is longer. Stopping seems to facilitate temperature rise. Also, I am using synthetic oil and I am not sure Steve was when he was monitoring temperatures.
The Mighty Mite type fans dont direct an air stream on the TwinCam head temperature sensor like a center mounted fan would and the TwinCams also have a tunnel behind the spark plugs to give air better access to the heads, so the TwinCams might actually have cooled better with that type of dual fans system. The amount of cooling the oil did in TwinCams was negligible though. Since the M8 is actually oil cooled I think the best way to bring ETs down is by cooling the oil better. This has already been proven by the differences in Steves readings between no fan and fan installed.
I can see what youre saying with the fans on the TwinCams. My ETs would run about 270 F on the highway. When I would get off the highway and come to a stop in town my ET would drop about 20 degrees. So thinking about it, the fans were probably cooling the sensor way more than they were actually cooling the head. Jason had a bike fitted with extra sensors and he did a lot of research on how well his fans worked. Unfortunately, when he took down his website that was lost, at least I dont have it.
Road Captain
Joined: Jun 2006
Posts: 723
Likes: 62
From: Cape Cod, Ma.
What are you using to record the engine temps? I assume it's taking data from the ECU and the temp sensor on the rear cylinder. I'm using a Power Vision and I'm seeing average temps in the 320- 350 range. 17 RGS, lower fairings, stage 1 AC, stock head pipe and Jackpot slip ons. I checked with Fuel Moto and DynoJet and the temps I'm seeing are average according to both.
Neil
RDMC
Neil
RDMC
Yes, that is the sensor Harley refers to as engine temperature (ET). As far as I know there is no other sensor that reads a temperature on the engine.
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What are you using to record the engine temps? I assume it's taking data from the ECU and the temp sensor on the rear cylinder. I'm using a Power Vision and I'm seeing average temps in the 320- 350 range. 17 RGS, lower fairings, stage 1 AC, stock head pipe and Jackpot slip ons. I checked with Fuel Moto and DynoJet and the temps I'm seeing are average according to both.
Neil
RDMC
Neil
RDMC