M8 Twin Cooling engine temp info - don't close those vents!!
#41
01-23-2018, 05:36 AM
Road Warrior
#42
01-23-2018, 11:05 AM
Stellar HDF Member
Does everyone realize the differences in the measured heat from a twin cam vs M8?
It is for this reason you can not compare measured heat from the two.
For example, the old EVO Magneti Marelli EFI had the temp sensor mounted on top of the combustion chamber and needs 284 deg to come off warmup strategies.
In came the TC and the new, remounted sensor to back of front head. Due to this new mounting strategy the engine comes of warmup strategy at a measured 167 deg.
Now the new M8 comes along and immediate conclusions from comparing apples to oranges.
The best clue here is the felt searing radiated heat like the TC is not there. If the heat is there with the M8 it will be felt...just like the TC.
So, because the mounting location, depth of mounting hole, and engineering modeling for how they measure head temp and covert it to ET, comparing M8 temps to anything but M8s is just a waste of time and creates misinformation at best.
Bob
It is for this reason you can not compare measured heat from the two.
For example, the old EVO Magneti Marelli EFI had the temp sensor mounted on top of the combustion chamber and needs 284 deg to come off warmup strategies.
In came the TC and the new, remounted sensor to back of front head. Due to this new mounting strategy the engine comes of warmup strategy at a measured 167 deg.
Now the new M8 comes along and immediate conclusions from comparing apples to oranges.
The best clue here is the felt searing radiated heat like the TC is not there. If the heat is there with the M8 it will be felt...just like the TC.
So, because the mounting location, depth of mounting hole, and engineering modeling for how they measure head temp and covert it to ET, comparing M8 temps to anything but M8s is just a waste of time and creates misinformation at best.
Bob
The following 3 users liked this post by FLTRI17:
#43
02-02-2018, 11:24 PM
Having owned a M8 for all of 20 days, I was wondering, as I read this thread, why did HD put those vents on there if closing them was gonna do something bad to my new bike? I will say that I did have a coolant overflow issue a couple days ago, with vents closed. I’ve been putting break in miles on it every chance I get. After a 50 mile ride with temps in the mid to low 50s I parked it in the garage and the next day I find a small amount of fluid on the floor. I felt around the derby cover, and transmission and while looking under to see if I could spot anything I noticed some drops on the bottom of the R-footboard bracket. It appears there is an overflow tube that hangs down there. I looked at the reservoir and it’s just slightly below the cold full mark. Never had any high temp warnings and when I got how, the fans weren’t even running. I have had them kick on before, but they didn’t this day. Anyone else had coolant overflow?
#45
02-03-2018, 08:50 AM
Been running some vtunes with TTS on my 2018 Road Glide..Notoced engine temps were hotter with vents closed also and this was at 55 degree air temp.Normal running my engine temps stay around 325-340.Noticed the temp sensor is mounted on rear head on M8 so that makes it different from my 110 wet head.Like you say the heat is not felt as much on M8 as Vtwin but its there.I ordered the love jugs mighty mites and will check heat again when they get here.I am playing back the readings from my TTS tuner. Forgot to add that my bike is stock except air box and no cat factory headpipe.Waiting on mufflers.
Last edited by berniemc; 02-03-2018 at 08:53 AM.
#46
04-24-2019, 07:24 PM
6th Gear
Join Date: Apr 2019
Location: NW Florida
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
I'll add that I've accidentally closed my left vent unknowingly (not sure if I hit it when wiping the bike down and forgot to open it or if I grazed the lever with my boot) but can add myself to the list of the bike heating up fast. It didn't take 10 miles down the road, 68 degree weather, 60 mph, and a stop light to make the red light come on. It was completely closed, coolant was normal, and after some surging idle I managed to stall it and couldn't restart until cooled enough. Yikes. I knew it was hot, but that was interesting.
#47
04-24-2019, 07:37 PM
Thanks for the info Heatwave..
I rode my bike yesterday(warmest day of the yr),,, Ambient Temp was 82*F,,, MoCo definitely has the EITMS "On" at a lower setting then my 2013 was( Or is this the difference between a Twin Cooled & Non Twin Cooled?)... Once my bike was at full operating temp, every time I stopped at a Red Light it kicked in. I did notice my idle went up from 950 to 1000... As soon as I get the 1000 mile check up & service the FP3 will go on it...
I've always done my own Services & work, but with this being a new engine design and a CVO it's dealer services till the Warranty is out.
I rode my bike yesterday(warmest day of the yr),,, Ambient Temp was 82*F,,, MoCo definitely has the EITMS "On" at a lower setting then my 2013 was( Or is this the difference between a Twin Cooled & Non Twin Cooled?)... Once my bike was at full operating temp, every time I stopped at a Red Light it kicked in. I did notice my idle went up from 950 to 1000... As soon as I get the 1000 mile check up & service the FP3 will go on it...
I've always done my own Services & work, but with this being a new engine design and a CVO it's dealer services till the Warranty is out.
#48
04-25-2019, 12:26 PM
Former Sponsor
So an alternative way of tuning would be with our supercharger. Keeping the engine small, keeping the compression lower, running a sporty cam to get good cylinder filling and a free flowing exhaust so not to back up the cylinder pressure would give you a cool running engine when cruising or on idle but still give you more power than a st4 kit when you wanted it. On cruise the incoming air still goes through the intercooler so will also keep the head temps down. The power drain of the supercharger off boost is insignificant so would hardly load the engine.
Worth a thought
Worth a thought
#49
04-25-2019, 12:35 PM
Former Sponsor
#50
04-26-2019, 12:44 PM
Road Master
I've not had any coolant come out of my overflow tube. I keep my lowers vents open except when the ambient temps are below 40f, which isn't very often here in sunny SoCal. I will close the vents in colder weather to try to keep as much heat into the motor as possible.
A brand new bike that spits a bit of coolant out the overflow, once or twice, is probably not a worry, just a sign of the bike getting rid of too much coolant in the system.
A brand new bike that spits a bit of coolant out the overflow, once or twice, is probably not a worry, just a sign of the bike getting rid of too much coolant in the system.