Engine Heat in the Summer (reduction)

[xsjohn]

Rather than discuss the peticiulars........here is my take on the order of importance.........and there is no one thing that gets this under control ....it's a combination of things.................listed by my experiments in degrees......(as measured at the top end)

1. Carburetion -15
2. Air Flow -10
3. Oil Cooling -5
4. Compression -5

xsjohn

 

[aldo5468]

An easy, no cost way to improve air flow to upper engine area on later Specials is to invert the horn mounting bracket - it raises the horn up higher in the frame and slants it back at the bottom, opening up some area for air flow that the horn otherwise blocks somewhat in its stock location.

 

[gggGary]

5. Avoid sitting idling in heavy traffic on hot days. -50

It helps to live somewhere rural for this one to work.

 

[blue900]

Thanks I wrote them down and will get working on them

 

[pyrocentric]

Yeah I fear traffic jams and long stoplights in the summer. I'd mount a fan but the charging system would never handle it. Maybe I should carry a cooler on the back and dump ice on it while i'm stuck in traffic, haha.

 

[gggGary]

XS john since you have done so much already perhaps you would be willing to try exhaust wrap and see what effect it has?

 

[xsjohn]

Gary....never tried the wrap....some say if mine ran any cooler it would freeze up....

xsjohn

 

[VENMUS]

Just for the record, motorcycle engines operate best inside a certain range of temperatures. Like my 2007 CBR for instance, I don't just fire it up and ride away, I wait for it to warm up to around 125 before even riding away. This is a liquid cooled 4-cyl however and a different animal than the XS, I just use it for example.

If you run an engine too cool it's just as bad as running it too hot, so beware any folks that are trying to eliminate heat entirely. XSJohn I think is probably in a sweet spot with his setup, but the only way to tell would involve me putting my engineering brain to work and scientifically solving the heat issue. And for that I would need consistent and accurate temp readings, such as a temp sensor in the oil.

HTH
Logan

 

[xsjohn]

Oil sensor won't give you the cylinder temperature..........that is where the damaging and power robbing heat is.......my 8-1 runs just as strong as it did at 8.7-1 because my setup runs with less heat......it would be impossible to get mine to run too cool in the summer.......I mix 4 oz or so of 5-30 synthetic oil in mine for the cold starts........and let it idol till it warms some..........never hear any engine noises even at 90 ambient......where it runs at about 230 on the cylinders...........oil temp seems to be about 160 or so the best I can measure on the oil filter and measuring the cases where the oil is....using the top end cooler I came up with...definate summer bike now and pleasure to ride.....where it was definately not before........

xsjohn

 

[xjwmx]

6. Running in the torrential rainstorms of the last two weeks: -150


But someone answer this question first - why do we give a rat's azz about cooling it down? If it simply makes you like it better that's justification enough, without requiring it to be beneficial to the health of the engine. But doesn't it have a normal operating temperature range? Don't we let it warm up before we ride? Is it running hotter than the designers wanted it to, for some paranormal reason? I mean after all the reputation of this design is that it's ...er..."bullet proof" not a limp wick.

 

[pumps]

John- you forgot to post pictures of your air deflectors you came up with.

 

[xsjohn]

xjwmx...........I wouldn't even know where to begin with some of your post........

Yea....driving around in cold weather and the rain the plugs would never clean off and end up baking all the black crud to the Insulators...........never thought of tuning mine in the rain.......guess it would run cooler ...till the sun came out............

xsjohn

 

[CDNTX650]

But someone answer this question first - why do we give a rat's azz about cooling it down? If it simply makes you like it better that's justification enough, without requiring it to be beneficial to the health of the engine. But doesn't it have a normal operating temperature range? Don't we let it warm up before we ride? Is it running hotter than the designers wanted it to, for some paranormal reason? I mean after all the reputation of this design is that it's ...er..."bullet proof" not a limp wick.

Oh man. They run silly lean with stock bs34's as they are emissions friendly carbs from the 80's. for sure they run hotter than they are supposed to.

 

[XSLeo]

A very hot engine burns much cleaner. It just shortens the life of the engine.
To adjust the carbs, timing, adding extra cooling helps the engine last much longer.
"Bullet Proof" is a very good description of our 650 engines, they are that with some care. But to abuse them removes the Bullet Proofedness of a great engine.
Some people are content to hop up the 650 to much larger cc's and compresssion ratios. These same people know they will be rebuilding thier engines more often. they except this as part of the fun of a high performance engine.
Others would rather live with a little less performance and run the engines forever.
To each their own.

 

[TeeCat]

Guys, here is my take on Pete's idea. I have yet to get a thermometer and get temps, but plan to.

 

[danxs650mass]

looks like a vmax wannabee with those tubes so anyone have a good oil for summer time riding im gettn ready to change mine but was thinkin that some had a certian summer oil that works best for these engines

 

[TeeCat]

Actually, you're spot on... I took Pete's idea and literally envisioned way to apply it in a VMax sort of way... but with a retro twist. I wanted to use Hilborne-type scoops, but they're too big.

 

[XSLeo]

danxs, Most any 20w50 will work, a motorcycle specific oil even better.