2 stroke heatsinks

[puginfo]

i was just thinking of using the heatsinks of the 2 stroke bike engines for as class A project. this is only an attempt to be different than the norm. anyone know if these are of any good? not sure what is the termal resistance thou, could be poor as the Al+ block seems thick but can be easily machined down.

[neutron7]

the top of the cylinder heatsink would look cool as a heatsink. it is designed to do the same job (get rid of heat) so as long as its big enough you should be fine.

[Magura]

The ones found on bikes are too small, but if you find an old airplane star engine to scavenge, you may have gotten yourself something quite cool....and it will have a fair chance to actually work .



Magura

[Bigred]

hrmmm.... some of the air-cooled 2 stroke bikes I have seen and owned in the past appeared to have some pretty hefty fins. Looks like they would dissipate considerable amounts of heat to me.

[puginfo]

i have access to the machine shop to dimension this thing. but the material seems to be of harder AL alloy than the usual softer AL heatsinks. this is because the inner bore also houses the piston to work against the surface.

i still suspect the thermal resistance could be high.

[OzMikeH]

Brilliant Idea!

flathead ford v8 heads...
http://www.vanpeltsales.com/FH_web/f...eed-edlbrk.htm

Multiple heads on a copper bus bar would work

Even better use the whole head and cylinder.
bolt it to a plate and seal it, fill with transformer oil or water thru the spark plug hole. mount you devices to the bottom plate.


Class A stereo Harley Davidson would be very cool.

[Variac]

nothing wrong with overhead valves though:

http://www.moroso.com/catalog/images/68430_part.jpg

This valve cover has vestigial fins and a lot of surface area AND a place to put the components!

A cast aluminum finned oil pan might be better..

http://www.bahnbrenner.com/vw_audi/O...an___4cyl.html

[OzMikeH]

I just thought of something, don't completely fill the cylinder with fluid, leave some air space for expansion and screwing the spark plug in. or it WILL leak no matter how well you try to seal it.

There are some nice finned diff covers for Dana 44 and Dana 60 depending what size you want. nice big round bowl shapes.

valve covers may not have enough surface area for more than about 5 watt class A amp. very thin too, high thermal resistance unless you mount a thick plate on the bottom and oil fill them too.

[puginfo]

have been on a set of junked ajs units below. they are about 8ins finned towers. can mill the bores down for 2 flat sides to mount devices and then fit a computer grade fan atop with bottom open for air inlet. tough getting the toroidal in as well thou.

[ilimzn]

Originally posted by Bigred
hrmmm.... some of the air-cooled 2 stroke bikes I have seen and owned in the past appeared to have some pretty hefty fins. Looks like they would dissipate considerable amounts of heat to me.

The thing is, you never run the engines flat out without moving - the heads are designed to have air streaming around them, either from the bike moving itself or from an impeller. This makes a heatsink of any king MUCH more efficient. Also, air cooled engines run at considerably higher temperatures than your semicondustors can stand... so take that into account as well.