Titanium Valve spring collars (Worth it ?)

[barnett468]

I don't think I have much more that I can do.

You can also anodize the cylinder and head . . this will increase cooling even when not moving.

if your cylinder cranking pressure is over around 185, i wuold run a spark plug that is 1 step cooler than stock in it.

[RUNMEDOWN]

In general, removing material from the fins will make an engine run hotter, not cooler . . its simple physics.

Please post the articles you read regarding this.

I just re-read the article, clearly written by someone who did not understand the subject (It could not be me not fully understanding the article). But I bought it, I am glad that I did not start cutting yet.
I will post a link.

Bottom of page 598 "From the experimental study it is found that the heat
transfer rate in notched fins is more than the unnotched
fins. The average heat transfer coefficient for without
notched fin is 8.3887 W/m 2 K and for 20% notched fins it is 9.8139"

http://www.ijetae.com/files/Volume2I...E_0412_101.pdf

[barnett468]

The other side of my thought is that the old 200e big reds would sit at idle all day and run at low speeds with much smaller cooling fins on basically the same motor and they never had any over heating issues. Is it b/c of the mods that I will have issues?

engines are designed to run at the proper temp for their intended use . . honda knew that the big ed would be left idling in blazing heat for long periods of time and designed it accordingly . . increasing the power and compression of any engine will increase its cooling requirements . . it is possible to exceed the engines ability to cool properly if enough performnce mods are done and/or it is ridden wot up steep hills in the sand when it is 297 degrees outside.

[RUNMEDOWN]

engines are designed to run at the proper temp for their intended use . . honda knew that the big ed would be left idling in blazing heat for long periods of time and designed it accordingly . . increasing the power and compression of any engine will increase its cooling requirements . . it is possible to exceed the engines ability to cool properly if enough performnce mods are done and/or it is ridden wot up steep hills in the sand when it is 297 degrees outside.

I don't know about you but I don't ride when it is 297 degrees Fahrenheit out
Just thinking of surface area, as long as the width of the cut is less than the width of the material being removed (X2) that you would be creating more surface area with every cut. Then the issue of turbulence vs. flow would need to be factored in. (Hello, I like to overthink things) My new plan is to not cut slots except for the area I had to reduce the length of the fin to clear the starter, I will also remove the paint from the fins and let it be.

[barnett468]

I just re-read the article, clearly written by someone who did not understand the subject (It could not be me not fully understanding the article). But I bought it, I am glad that I did not start cutting yet.
I will post a link.

http://www.ijetae.com/files/Volume2I...E_0412_101.pdf

ok, xnt . . i just skimmed over it but he is referring to static [not moving] objects such as heat sinks on computers and fins on generators which also do not use a fan to cool them, therefore this does not apply to your app in any way.

your fins are primarily designed to function when air is forced over them . . as you move forward, the air enters the fins from the front and part of it escapes out the side and some of it continues along the length of the fin . . any break/gap in the surface of the fin will create turbulence which will reduce air flow after the break/gap which will then allow the area that is rearward of the break/gap to get hotter than it should.

yes i know there were some aftermarket cylinder heads like the dg for the cr125 and 250 and the one for the cz's that falta had on his works bike that used staggered fins, but that in no way meant they were more effective and may have partially been a marketing tool . . if the mfg said it worked better, it must have, but then one should ask themselves why other high perf aftermarket parts mfg's or bike mfg's used straight fins instead . . one think is for certain though, back in the 70's, people thought that staggered fins made their bike ook more aggressive and "works" like so many people bought these types of heads for that reason alone . . i put one on my "works" 1974 CR125 for that very reason.

FMF Porcupine head




DG GOLD head . . Notice the silencer coming thru the middle of the rear fender in the wheel area.




1976 falta replica

[RUNMEDOWN]

Cool looking head. That was exactly what I was thinking. I had a dg head on my FL250

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[barnett468]

I don't know about you but I don't ride when it is 297 degrees Fahrenheit out

I have well over 1,000 hours of riding and racing time in temps above 90 degrees in all types of terrain and under racing conditions, it certainly felt like 297 degrees . . the endurance tests we did on the first tecates and klt 110 were conducted in 90 degree plus heat . . i like to ride when its hot, but i like to ride when its cool and i guess i like to ride when its raining and muddy too because i did a lot of it.

yeah unless the paint is a dedicated emissive coating, it will only reduce the cooling affect of the fins . . they do sell emissive paints but they are not very effective, and anodizing is many times more effective.



fu0-raceddid

[barnett468]

Cool looking head. That was exactly what I was thinking. I had a dg head on my FL250

yeah, that FMF head just has wicked written all over it . . the dg head is just the opposite with is elegant, smooth, radial design.

i saw a lot of fl250 races and you couldn't pay me to race one of those things because it looked like it would shorten ones spine when landing off the jumps . . saw a lot of them flip over too . . i actually felt sorry for those guys.

[RUNMEDOWN]

That's why I sold it. Just too rough of a ride for me as I get older.

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