what is the max cly head temp on the gs before problems? i am going to be installing a gauge for some personal reasons, and then some performance ones latter.

I doubt anybody knows.  Are you planning to heat up your cylinder head?  Why?  There might be some kind of general guideline for max operating temp. of aluminum heads but I can guarantee nobody here has ever tested it.  Why would they?

-M

try this page,
http://66.249.93.104/search?q=cache:th5nqKt7vRgJ:www.nortonclub.com/docs/OilTemp.pdf+cylinder+temp+on+motorbike&hl=en&gl=uk&ct=clnk&cd=1 i know its not a gs but its air cooled, so mabee it'll give you a guideline to work from

4 brazilian degrees celcius

i am trying to prevent over heating the engine. turbo project.

you don't really want to know...it will scare the sh!t out of you

used to work on legends cars....peg the gauge...BURN SYNTHETIC OIL!!!!!!!

engine mounted sideways and didn't get air to back two cylinders


just figure 300-350 F

ok, also the boiling point of most oil, ok now i have a base line

I'm not sure about motorcycle engines, but you might take a cruise on the FAA TCDS server and look at permissable operating temperatures.

Actual temperature depends on where you measure.  The standard measurement point is at the spark plug base, or as close to it as possible.  As a general rule barrel maximum temperatures are around 300 degrees F, but cylinder head maximum operating temperatures can be as high as 500 degrees F.  This is using 100 octane gasoline at around CR 8.5:1  YMMV

Scratch made a post not too long ago with his measurements of CHT and case temperature.  Maximums were in the high 200's as I recall, which suprised me.

I would suggest you just try it and see.  You'll quickly figure out where the problem areas are.  I suspect valve coking and exhaust valve temperature will be the limiting factors.  A few quick calculations will give you a rough idea of the maximum amount of heat you can shed with the existing cooling scheme. 

If you want to sit down and calculate, read "The Internal Combustion Engine in Theory and Practice"   Volume 1, Thermodynamics, Fluid Flow, Performance" by Charles Fayette Taylor.  Chapter 8 "Heat Losses" would be of specific interest.

Let us know what you find.   

I can't say much as for the cylinder head temperature, but I can say that with a turbo you'll probably have to be moving some serious air over the fins to even stand a chance.

I can't come up with a way off the top of my head to mod the cooling system in a way that would be able to handle as much heat as you are planning on making.

I say ditch the fairing first.

Maybe a fistfull of 100+ cfm fans? (Copper stuff I dunno, fishing here.)

Geep, I think I'll have to have a look at that book, sounds like something I would read from cover to cover. (I am a dork like that)

Quote from: GeeP on July 07, 2006, 07:29:01 PM
I'm not sure about motorcycle engines, but you might take a cruise on the FAA TCDS server and look at permissable operating temperatures.

Actual temperature depends on where you measure.  The standard measurement point is at the spark plug base, or as close to it as possible.  As a general rule barrel maximum temperatures are around 300 degrees F, but cylinder head maximum operating temperatures can be as high as 500 degrees F.  This is using 100 octane gasoline at around CR 8.5:1  YMMV

Scratch made a post not too long ago with his measurements of CHT and case temperature.  Maximums were in the high 200's as I recall, which suprised me.

I would suggest you just try it and see.  You'll quickly figure out where the problem areas are.  I suspect valve coking and exhaust valve temperature will be the limiting factors.  A few quick calculations will give you a rough idea of the maximum amount of heat you can shed with the existing cooling scheme. 

If you want to sit down and calculate, read "The Internal Combustion Engine in Theory and Practice"   Volume 1, Thermodynamics, Fluid Flow, Performance" by Charles Fayette Taylor.  Chapter 8 "Heat Losses" would be of specific interest.

Let us know what you find.   

good thinking, i will check the cessna 421 books at work tomarrow, the max ground heat should give me a idea, all info on  searched show that 300 is the max safe llevel and 425 is cridadal  but this can an will be countered with
runign it rich and using the 100LL or 130 A/C fuel that we toss, (tank drains and sumps, can't be used in a/c) plus this little wonder, i may even go larger