Avgas viz Mogas
Posted: Mon Aug 02, 2010 10:37 pm
Having just finished a Jabiru 430 I am now awaiting the P to F.
So now I switch my thoughts to operational matters.
The engine is a Jab 3300A no 978. So I believe it is the low compression model and has the modified carb needles.
So as I see it, the engine is certificated to run on either Avgas LL or Mogas 95 or higher. But there seems to be a conflict, Mogas is a cleaner fuel but loses its octane rating with time, thus causing pinking; whereas Avgas LL avoids the pinking but leaves a lead deposit which causes the head to become contaminated?
I appreciate Mogas is cheaper but this is small beer compared to the cost of an early engine overhaul or even long term damage.
So should I alternate fill ups between the two fuels or should I go for the higher octane unleaded fuel 98+ which to some extent will take longer to degrade below the minimum 95 allowed.?
I am also aware that alcohol is now being added to Mogas, 10% seems to be the limit, but how do I test for its presence?
Any thoughts please?
John F
So now I switch my thoughts to operational matters.
The engine is a Jab 3300A no 978. So I believe it is the low compression model and has the modified carb needles.
So as I see it, the engine is certificated to run on either Avgas LL or Mogas 95 or higher. But there seems to be a conflict, Mogas is a cleaner fuel but loses its octane rating with time, thus causing pinking; whereas Avgas LL avoids the pinking but leaves a lead deposit which causes the head to become contaminated?
I appreciate Mogas is cheaper but this is small beer compared to the cost of an early engine overhaul or even long term damage.
So should I alternate fill ups between the two fuels or should I go for the higher octane unleaded fuel 98+ which to some extent will take longer to degrade below the minimum 95 allowed.?
I am also aware that alcohol is now being added to Mogas, 10% seems to be the limit, but how do I test for its presence?
Any thoughts please?
John F