This is not a thread about aliens! I am talking about engine temperature. I've been doing some monitoring the last couple days and I have some figures for those that are interested to digest. My bike is a 2017 RGS 107" with a RS468 cam, an Arlen Ness Big Sucker air cleaner, decatted stock header, and the stock muffler cans with Fullsac 2" cores. It also has the fan on the oil cooler.

Let's start with looking at the figures Steve Cole recorded when he was monitoring his bike temperatures. He had a few more sensors than I have so he was also monitoring the oil temperatures. Here's his results:

Steve's results with no cooler fan:

Conditions:
Ambient temperature during testing upper 70's
In Town riding with little traffic but normal stop lights
Speed limited to posted speed limits (35 - 45 mph)

Results:
Measured Peak Engine temperature = 340 F
Measured Peak Oil Sump temperature = 267 F
Measured Peak Head Oil Return temperature = 290 F

Steve's results with the oil cooler fan:

Conditions:
Ambient temperature during testing low - mid 70's
In Town riding with little traffic but normal stop lights
Speed limited to posted speed limits (35 - 45 mph)

Results:
Measured Peak Engine temperature = 302 F
Measured Peak Oil Sump temperature = 201 F
Measured Peak Head Oil Return temperature = 240 F

So I haven't had a chance to get any figures in the temperature ranges he was operating in yet. I hope to be able to do that tomorrow morning. Here is what I have recorded.

Ambient temperature: 101 F Peak engine temperature 304 F
Ambient temperature: 91 F Peak engine temperature 297 F
Ambient temperature: 104 F Peak engine temperature 298 F
Ambient temperature: 108 F Peak engine temperature 317 F This was on the highway running 75-80 mph at 3000 to 3200 rpm
Ambient temperature: 106 F Peak engine temperature 306 F This is when I exited the highway. Hit an area where the ambient temperature was a little lower. I also had turned so the sun was behind me. I was cruising at 50 mph @ 2300 rpm.
Ambient temperature: 108 F Peak engine temperature 315 - 322 F A couple miles after I exited the highway the ambient temperature increased. The ET went up to 315 F and held pretty stead there until was about a mile from the house. Then the temperature increased to 322 F. I really don't know what the reason for this was.

This is what I have thus far, I do plan to record some more this weekend as the temperature is suppose to be 110 F. This is starting to reinforce my desire to install a second oil cooler. I think it would help, especially on the highway.

 

[QUOTE=$tonecold;18361398
Ambient temperature: 101 F
Ambient temperature: 91 F
Ambient temperature: 104 F
Ambient temperature: 108 F
Ambient temperature: 106 F
Ambient temperature: 108 F [/QUOTE]

I'd be more concerned about what your H2O consumption was and if you are using Synthetic SPF 75-140 !!!!

 

By peak engine temp...do you mean cylinder head temp?

 

What’s interesting to me is I see similar temps in milder NY heat. I was out yesterday on my RKS in 88deg weather and was seeing right around 300 most of the time. Up a few degs when just off a highway run, and when I’m stop and go around town. Otherwise pretty stable around 300. Haven’t broken 310.

I also have the HD fan assist oil cooler and a pair of Love Jugs Mighty Mites. Which seem to make less of a difference on the M8 as they used to on my TC’s.

The numbers are also Interestingly different from from my old 110 TC numbers, which were always up around town then would drop considerably when at highway speeds. By a good 10-20deg.

 

This is starting to reinforce my desire to install a second oil cooler...


I think that brand/type of oil used, as well as miles on current oil, would make a difference too. Why not try a couple of popular brands to see if there's much difference, but starting with a fresh change of whatever you are currently running.
Dutchy

 

The fans that people added to TwinCams to cool the heads, gives a false sense of cooling. If you look at the placement of the fans they were directly blowing air at the ET temperature sensor due to it location. This cooled the sensor down but did very little to really cool the engine. Now with the M8 the ET sensor is placed on the opposite side of where the fans are located so what you are seeing is more inline with what is really going on.

 

OK, but then the smaller, yet still significant temp drop obtained by the fan on my M8 would validate its ability to cool, (even if slightly) the motor, yes?

 

so these cooling fans blow air at the engine instead of drawing the heat away from it, like the HD Cool Flow Fan and Fan Assist oil cooler do? wondering if they wouldn't be more effective pulling the heat away..just curious

 

Well, I'm no expert on thermodynamics, but in this scenario its way better this way, from the rider standpoint. While you do get a *little* blowback from the current "blow towards" design, having that fan blowing hot air on your leg, as it would in a "pull away" design, would be pretty uncomfortable. I think it does the job as-is. You're still exchanging heat either way...

 

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