Euro 5 compatibility?

Al's#5 · Nov 28, 2020

Fed up with the excuse that we can't have an air cooled engine that will comply to new emission standards and suddenly, out of the blue, Ural are bringing out an outfit to suit driving on the left and comply to Euro 5. Same old engine by the look of it but Euro 5 compatible, what's the secret?

kommando · Nov 28, 2020

They employed VW engineers

BritTwit · Nov 28, 2020

Al's#5 said:
Fed up with the excuse that we can't have an air cooled engine that will comply to new emission standards and suddenly, out of the blue, Ural are bringing out an outfit to suit driving on the left and comply to Euro 5. Same old engine by the look of it but Euro 5 compatible, what's the secret?

I don't think there is a secret here.
Of course engineers can make an air-cooled motor Euro-5 compliant, or compliant to most any standard for that matter.
But what do you have to lose to meet that standard.
Well for sure you will have to drop the compression ratio, and retard the ignition timing, and lean out the fueling, reducing the power.
Most manufacturers don't want to reduce power, performance is a selling point.
So companies would rather move to a new liquid cooling design to maintain performance, reliability and have a updated design that has a production future.

I think Urals put out 40 horsepower or so from a 750cc twin, so it is fairly de-tuned to begin with, even as an air-cooled motor.
So screwing a bit with the fueling and CR isn't going to have a great impact on its overall performance.
Generally, folks who buy Urals are not looking for high performance.

Al's#5 · Nov 29, 2020

BritTwit said:
I don't think there is a secret here.
Of course engineers can make an air-cooled motor Euro-5 compliant, or compliant to most any standard for that matter.
But what do you have to lose to meet that standard.
Well for sure you will have to drop the compression ratio, and retard the ignition timing, and lean out the fueling, reducing the power.
Most manufacturers don't want to reduce power, performance is a selling point.
So companies would rather move to a new liquid cooling design to maintain performance, reliability and have a updated design that has a production future.

I think Urals put out 40 horsepower or so from a 750cc twin, so it is fairly de-tuned to begin with, even as an air-cooled motor.
So screwing a bit with the fueling and CR isn't going to have a great impact on its overall performance.
Generally, folks who buy Urals are not looking for high performance.

Agreed, engineer our way around it! Not a solution for the men with the money it would seem, pity! It was just that while having a beer, sat next to a blazing fire and looking at my winter hack I start to think, dangerous I know but ok, it's water cooled but the cooling rarely kicks in, 600cc, high compression, large air intake, twin exhaust ported, ok only Euro 4 but no O2 sensors or cat exhaust. Simple but very effective. Surely with the right materials and some clever design we could have another big air-cooled single, twin, v-twin. Long live the dinosaur!

Bernhard · Nov 29, 2020

BritTwit said:
I don't think there is a secret here.
Of course engineers can make an air-cooled motor Euro-5 compliant, or compliant to most any standard for that matter.
But what do you have to lose to meet that standard.
Well for sure you will have to drop the compression ratio, and retard the ignition timing, and lean out the fueling, reducing the power.
Most manufacturers don't want to reduce power, performance is a selling point.
So companies would rather move to a new liquid cooling design to maintain performance, reliability and have a updated design that has a production future.

I think Urals put out 40 horsepower or so from a 750cc twin, so it is fairly de-tuned to begin with, even as an air-cooled motor.
So screwing a bit with the fueling and CR isn't going to have a great impact on its overall performance.
Generally, folks who buy Urals are not looking for high performance.

Those boxer engines with a reverse gear were, I think, copies of the BMW bikes captured durning WW2. As they were free, I beleive a lot of Russians swapped 2 Urals for one BMW !

Euro 5 compatibility?

Al's#5

kommando

BritTwit

Al's#5

Bernhard

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