Microlighters

Hi Guys , been reading the forum and there are lots of references to 582 Blue Top and Grey top .
What exactly is a Blue Top or grey top and what are the differences .
Thanks

I am not a Rotax expert but from my reading its more an evolution of the 582 engine. The first 582s were the Grey tops and the new ones which are still available are the Blue tops. The principle difference seems to be a more sophisticated two circuit water cooling system in the Blue top which was presumably implemented after some problems were encountered with the Grey top. Most specifications etc. seem to be the same for both models. Rotax in the manuals seem to refer to the Grey Top as model 90 and the Blue Top as model 99. Would like to hear from someone with more expertise as well.

My understanding is the Greytops did not have a bypass hose in the cooling system to citculate the water through the cylinders and head when the thermostat was closed. This could cause cold seizing when decending on cold days as the thermostat would close and the all he water in the radiator would chill as it was not circulating. Then when sufficient power is applied to warm up the motor enough to open the thermostat, very cold water leads to rapig chilling of the cylinders while under load and possible seizing.

Not really a problem in our climate and can be reduced by occationally applying power on decent. (Also geed for non auto lube engines)

On old cars without a bypass system it is common to drill a small hole in the thermostat - say 6mm Diameter.

The cooling system design of the Blue Top 582 is copied off the Rotax 618, the bigger brother of the 582. The 618 has not been made for aircraft use for a number of years. The water pump outlet on the Blue Top and 618 Rotax has two outlets as opposed to the Grey Top 582 with only one outlet. Also the Blue Top has blots holding the head down whereas the Grey Top has studs with capnuts.
Jean.

Guys
Thanks for the response .
Question asked and answered
Now for the 1000 and 1 others I have
Am looking at 2nd hand trike and this has come up quite a bit , thanks ,Now I am better equipped to make a more informed decision ,
It seems that for our conditions , it does not make a difference whether the trike has a Blue or Grey top , they are just different versions of the same engine .
Once again thanks for the info .

It seems that for our conditions , it does not make a difference whether the trike has a Blue or Grey top , they are just different versions of the same engine

Finally, someone who understands.
Hopefully this will help those who think they ABSOLUTELY MUST have a Bluetop for better performance or maybe its just an ego thing?

Duck Rogers wrote:

It seems that for our conditions , it does not make a difference whether the trike has a Blue or Grey top , they are just different versions of the same engine

Finally, someone who understands.
Hopefully this will help those who think they ABSOLUTELY MUST have a Bluetop for better performance or maybe its just an ego thing?

Wish there was a like button on microlighters

I fly a Silver Top and I really love it

Now the only thing I want to know is...can I make the top yellow to go with my trike

Rustoleum Madman.......????

Madman, PLEASE don't do that, you will then start a whole new discussion about which is better, the silver top, the blue top or the yellow top

Rust-Oleum actually does have a product to make the Silver Top a Yellow Top

Yeah Dobbs, that would be insane

If people are able to change the color of heads on cars, what difference would changing the color of the Silver top be

Would changing the color mess with the heating/cooling of the motor

It would really just look cooler in yellow

Paint the damn thing red. It will add at least twenty horsepower.

Boet wrote:Paint the damn thing red. It will add at least twenty horsepower.

GT Red that is.....GT Red.
Jean.

GT Red will make it fly faster