Cleaning engine fins and cases.

Just wondering if anybody has some tips on cleaning and or polishing the the engine. I figure I will just take the clutch cover,cam cover, etc off and polish them with the bench grinder, but what are you guys useing to clean up around the fins and top of the cases. ie what tools and or chemicals work best? I have the engine out of the bike but it's running fine so I don't really want to dissaseble it too far when it's not really nessesary. Also I'm not a big fan of painting air cooled motors, tends to make them run hotter in my experience.

I did paint mine recently, used Duplicolor Engine Enamel - with Ceramic. It is supposed to help disipate heat. We'll see how it goes. I used Muthers Al. polish on the side cases, with fine steel wool, it really worked great, with very little effort.

The fins and engine case are cast aluminum, so they'll never shine like chrome, but you can brighten them up alot.
I've experimented with different stuff, and I think a scotchbrite pad dipped in Mothers Aluminum Polish works great.
You can fold the pad so it fits between the fins, and it gets in the nooks & crannies. You have to buff the mothers off with a clean cloth, and I use a wooden dowel to force the rag between the fins. It takes time, but with some beer, a stool, and a sunny day, it's not bad duty.

Post edited by: ltdrider, at: 2006/04/25 12:39

Maxwedge wrote:

Also I'm not a big fan of painting air cooled motors, tends to make them run hotter in my experience.

I have been doing some research on heat dispersion calculations.. and ran across this statment in a tech document...

"Unless the component is facing a hotter surface nearby, it is imperative to have the heat sink surfaces painted or anodized to enhance radiation."

I'm gonna look into this a bit more.. i find it interesting..

KzJim wrote:

"Unless the component is facing a hotter surface nearby, it is imperative to have the heat sink surfaces painted or anodized to enhance radiation."..

Hmmm...interesting... I know my FJ1200 seemed to run hotter after I painted the motor. But it may very well depend on the type of paint used too, that paint was pretty thick.

Thank's for the Mothers & Scotchbrite tip. Never tried that one before.

depending on how carried away you want to get.i start out with an aluminum file to flatten out the edges of all the fins and rough spots i can get at then i blocksand everything to make all look nice and smooth.a dremel with small sanding drums works good for smoothing out round or curved areas you can always go back with sand paper to fine tune things.you just have to make the best tool to work with your situation in some cases.a piece of sand paper wrapped around something flat like a paint stirring stick works good between fins on head ,fine steel wool works good in some places.before you start buffing on case covers give them a good block sanding,you be amazed how wavy they really are it will make a hell of a differance in finished project. goodluck,happy wrenching!

ltdrider wrote:

The fins and engine case are cast aluminum, so they'll never shine like chrome, but you can brighten them up alot.

I thought the cases were magnesium

Maxwedge.. ya it dosent seem to make sense does it?.. I did talk to a heat-sink manufacture today and was told that a smooth surface will not allow air-flow to be disturbed, if the surface is rough it will cause turbulance and then the air will cavitate, also the finished surface will not allow dirt to stick....

Being the curious fellow i am.. i took apart all 3 PC's in the house.. sure 'nuf... all 3 heat sinks' on the processors are 'painted' black. (i'll use the word 'paint' because i dont know just what the finish exactly is).
There has to be a better answer.. I'm gonna find it...

according to what ive always been told by higher ups flat black is the ultimate for heat disipation. but i still prefer the look of clean aluminum myself. :whistle:

kx_125_pilot wrote:

ltdrider wrote:

The fins and engine case are cast aluminum, so they'll never shine like chrome, but you can brighten them up alot.

I thought the cases were magnesium

ive seen a lot of older dirtbikes with magnesium cases,but 900-1000 cases have always been aluminum as far as i know.

Black and rough ( increases surface area) are suposed to be the best qualities for heat dissipation. while polished alum isn't very good.

I'm not sure about painted surfaces though. I do know that the motor in my bike is painted with alumiblast from the eastwood corp., and the cleared with ppg graphiti resistant clear. It looks awesome, but it sure don't radiate heat very well. It also yellowed really bad in some spots on the head. It sure does clean up easy though, oil wipes right off, where it would just stain bare cast.

wireman wrote:

according to what ive always been told by higher ups flat black is the ultimate for heat disipation. but i still prefer the look of clean aluminum myself. :whistle:

I agree I like the EL NATURAL look my self better might be a little more work in the beginning but once cleaned to your preferance any and all clean up is easyly done.