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Powder Coating The Jug

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hey all,

Its winter time here and I am gettin stuff laid out to do to my CR

for next season. I was wanting to know since I have the jug off

could I take it down and get it Powder Coated?? or would it be bad??

I read that powder coating will trap heat on car engines but didnt know if

it was the same on these 2 strokes.

let me know

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hey all,

Its winter time here and I am gettin stuff laid out to do to my CR

for next season. I was wanting to know since I have the jug off

could I take it down and get it Powder Coated or Anodized ?? or would it be bad??

I read that powder coating will trap heat on car engines but didnt know if

it was the same on these 2 strokes.

let me know

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I would NOT powder coat the cylinder. Reason being is Heat Transfer. With a thick powder coat on the cylinder, the transfer of heat from the cylinder to the ambient air will be reduced. As a result you run the risk of running a lot hotter too. I don't see the powder coating holding up very well either.

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The cylinder is liquid cooled, not air cooled. The powdercoat would have zero effect. I had the cylinders on my HD Shovelhead powdercoated black about 12 years ago, with no ill effects. Powdercoat is polyurethane, the same as polyurethane paint, but is not solvent borne. Black pigments absorb heat, which is then transferred to the air. Remember when almost all air cooled motorcycle engines were black?

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There is still heat transfer that takes place between the cylinder and the ambient air. If you don't believe me, touch your cylinder after riding.. And another thing, after you turn the bike off momentarily (say on the trails) how is heat supposed to escape from the cylinder if you have a thick coating on it?

Also, since the cylinder head is made of aluminum, you would deal with expansion and contraction from the heat cycles, so since the powder coating is a brittle coating, it would likely crack and flake off.

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There is still heat transfer that takes place between the cylinder and the ambient air. If you don't believe me, touch your cylinder after riding.. And another thing, after you turn the bike off momentarily (say on the trails) how is heat supposed to escape from the cylinder if you have a thick coating on it?

Also, since the cylinder head is made of aluminum, you would deal with expansion and contraction from the heat cycles, so since the powder coating is a brittle coating, it would likely crack and flake off.

^^^He is right. The thermal conductivity of powder coating is low, and it will effect heat dissipation. Enough to cause problems? I don't know, but it's definitely a valid concern. And I believe they use a different type of coating on old air cooled motors.

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^^^He is right. The thermal conductivity of powder coating is low, and it will effect heat dissipation. Enough to cause problems? I don't know, but it's definitely a valid concern. And I believe they use a different type of coating on old air cooled motors.

My first thought is that it won't hurt anything, since obviously a water cooled bike is going to be cooled by the radiators and not air. Jet skis often have powder coated parts, but that may be different because they have a constant supply of fresh, cool water running through. Radiator water doesn't really get the chance to cool all the way down.

Didn't Husky have some of their 4 stroke heads powder coated for a while? :lol:

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Are you sure they were really powder coated? Paints that are used on cylinders, and other engine components are generally very thin high temp paint and sometimes promotes heat removal (from the engine) depending on the paint.

Some may argue about older engines being painted...the components were painted with a thin layer (usually to combat corrosion) that had negligible effects on heat transfer. Powder coating is thicker and as mentioned above, has a low thermal conductivity. As a result, heat is trapped below the powder coat layer.

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iv run plenty of custom motorbikes(choppers,bobbers ext) with powder coated motors....air cooled to boot.

never had a problem with over heating. and i only saw a raise in a few degrees in oil temp.

iv done 2 dirtbikes with powder coated jugs..iv also done 3 sleds(snowmobiles) with powdercoated jugs.

powder coating will last on a motor. and will nto effect how it runs(wont over heat because of the coating)

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Chopper bikes are generally under lower loading than a motocross race bike.

Snowmobiles...well heat transfer revolves around delta T (change in termperature) ..so the greater the temperature difference, the better the heat transfer. So snowmobiles are generally operated in cold ambient temperatures.

As to powder coating lasting on a motor...it all depends on how well the powder coater does. I've seen crappy powder coating jobs, and I have seen good powder coating jobs so...

Not saying that powder coating won't work on the cylinder...just saying I wouldn't do it.

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What about one of those coatings that transfers heat better than a non-coated surface? Do they come in any cool colors?

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Unfortunately you are not going to find any coatings that will transfer heat better than a non coated surface that is economical. There are coatings out there that help dissipate heat better, but I am not aware of any particular ones off the top of my mind.

If a painted surface is needed, then a black matte color is desired for high emissivity. This means that black will dissipate as well as absorb heat better than any other color via infrared radiation (Ever wonder why radiators are commonly painted black?) For a cheap option, Duplicolor sells high temperature engine paint that will work.

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First of all, powder coat is not brittle, it's is quite rubbery and flexible. It will last just fine on the cylinder without any worries about it burning off. I have powder coated exhaust systems with silicone based powder with no issues what so ever. Never had a powder coating job crack or chip, that only happens when the prep work isn't completed properly (mass production, beginner powder coaters etc).

As for the heat transfer pro's and con's, that I do not know.

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It's water cooled. dissipation to the air is non-essential. Powder coat it if you wish, it's not going to hurt anything. If there is a difference in running temps afterward, I very seriously doubt it would be noticable. You could probably put one of those stupid little finned aluminum sections in the radiator hose and make about as much difference.

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It's water cooled. dissipation to the air is non-essential. Powder coat it if you wish, it's not going to hurt anything. If there is a difference in running temps afterward, I very seriously doubt it would be noticable. You could probably put one of those stupid little finned aluminum sections in the radiator hose and make about as much difference.

This, it's a non issue on a water-pumper. FWIW my old Harley has powder coated cylinder and heads, and it runs fine and the PC has held up very well.

True my chopper doesn't get run as hard as a dirtbike, but a dirtbike doesn't need to sit at a light for several minutes in 95* heat either.

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Chopper bikes are generally under lower loading than a motocross race bike.

Snowmobiles...well heat transfer revolves around delta T (change in termperature) ..so the greater the temperature difference, the better the heat transfer. So snowmobiles are generally operated in cold ambient temperatures.

As to powder coating lasting on a motor...it all depends on how well the powder coater does. I've seen crappy powder coating jobs, and I have seen good powder coating jobs so...

Not saying that powder coating won't work on the cylinder...just saying I wouldn't do it.

thankyou for that:banghead:

my street bikes get ridden hard. and each one has been to the drag strip, with multiple passes. not to mention riden slowly on hot, hot days at bike shows.

as for sleds, we do grass drags in the midle of summer. none of the sleds have over heated.

it will work, and it will stick as long as you get it done at a good shop that uses quality powder.

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Does it make the bike go faster? nope, then why waste the money to make it look cool?

why wash it? does it make it faster? nope. :lol: i like my bike to look nice and have seen alot of Duners do it around here.

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