Liquid vs. air cooled??

[Guest Crashbait]

Can anyone give me the skinny on liquid cooled vs. air cooled engines. No doubt we are talking Rotax vs. Jabiru given they seem to be the most popular power plants of choice in recreational aircraft. I don't have a preference as yet since I am only a learner pilot, but there seems to be a lot of argy-bargy out there in the aviation world, even though they both perform basically similar. It seems that if you're a Rotax man you'll always be a Rotax man (bit like Holden v. Ford) and vice versa!!

 

I hope to buy my own plane not too far down the track so some factual comparisons would be greatly appreciated. Cheers.

 

 

[Brett]

Depth of my pockets made my decision,,, can see anything wrong with air cooled engines in my location and the rotax water cooled system seem quite compact and will fit in pretty small cowling ,comes down to what you feel more comfortable with I suppose ,,, If I had the cash however I'd have a 100 hp rotax in what I'm building.

 

 

[Guest Maj Millard]

Liam, This one got done to death a couple of months ago, if you go back through the posts a bit you'll find it............................................................................

 

 

[wags]

Rotax has fall back position.

 

Liam... the Rotax has one nice feature that the Jabiru doesn't. If you loose the liquid coolant in the Rotax you can continue operation albeit at a reduced power setting on the basis of "get you home". Liquid cooling has better properties as far as thermal shocks go, so this should result in longer life in the case of the Rotax.

 

The Rotax also has a form of ceramic liner to the cylinders and just recently I inspected a Rotax 912 that had been pulled apart for inspection at 1750 hrs and the machining marks were still readily discernible on the cylinder walls. Don't think the Jabiru would come up the same at 1750 hrs but I might be wrong on that.

 

Please don't get the idea I dislike Jabiru's or think that one is better than the other... just want to point out some of the differences that you might like to take into consideration.

 

 

[Guest 4aplat]

Can anyone give me the skinny on liquid cooled vs. air cooled engines. No doubt we are talking Rotax vs. Jabiru

Hi

 

for me it's easy to compare

 

If you just have to "put" a rotax in a plane, you have to think a lot before installing a jab.

 

water helps cooling the engine in all conditions (idle, full throttle etc...)

 

MicheL

 

Jabiru-owner.com

 

 

[bushcaddy105]

Just to stir the pot!

 

Gooday Liam,

 

There are a considerable number of us homebuilders (probably mostly with shallow pockets like me!) who dare to use liquid cooled auto engines, as the vast majority of auto engines seem to be. They have lots of advantages, eg reliability and low initial and maintenance costs, when compared with their air cooled (or combination cooled in the case of 912's) brethren. Their big disadvantage is an inevitable weight penalty, but with careful design this can be incorporated into many aircraft designs. The Subaru family, for example, have an established track record along this path, and I for one am looking forward to exploring the emerging small high-tech diesels (all liquid cooled) which are appearing in many car makers new offerings. Keep your mind open!

 

 

[eastmeg2]

bit like Holden v. Ford

I tend to think of it more like Holden v. BMW :stirring pot: in line with geographical location of each.

 

There are plenty of good valid reasons why you might choose either, like $$$ and ease of maintenance.

 

Cheers,

 

Glen

 

 

[stanzahero]

Car engines are not designed to run at full revs for extended lengths of time though..

 

Just be aware there may be some reliability issues involved.

 

The oils that they are designed to use may also not be suitable for aerial applications either.

 

The AE81 Subaru engine is a long tested example having earned it's stripes over many years but not all automotive engines may fare as well.

 

That being said...

 

Ive always wondered how the little Toyota and Suzuki V6 would cope...

 

Stanzahero