Hangar Flying

Hangar Flying => Hangar Flying => Topic started by: Lowlevldevl on May 23, 2009, 05:53:49 PM

Title: Cross flow cylinders for updraft cooling?
Post by: Lowlevldevl on May 23, 2009, 05:53:49 PM

Has anyone considered converting an IO360 to use the same cylinders the Navajo uses? The IO540 in the Navajo has cross flow cylinders (exhaust out the top). I'd have thought that arrangement would be perfect for the updraft cooled LE. It would make it super easy to terminate the exhaust closer to the prop hub. I think I read somewhere here that contributes a lot to the thrust of our pusher props.

I have a dream that involves fuel injection, electronic ignition, an MT prop, longer nose with battery further forward to keep the CofG right and a super fast, efficient, high altitude, most weather cross country Long EZ.

Aside from the cost, anybody see any pitfalls here?

Title: Re: Cross flow cylinders for updraft cooling?
Post by: Drew on May 24, 2009, 04:20:47 AM

Things to consider (I prefer downdraft for a Longez)---other than what you can already read on this site:

Downdraft cooling: Extremely easy to baffle.  Since the cooling flow comes out the bottom side of the engine, you don't have to baffle around the starter, alternator, pipes, etc. 

Updraft cooling with the pipes on top: at least you won't have to baffle around the pipes---but I would not go to that trouble just for pipe placement.

Title: Re: Cross flow cylinders for updraft cooling?
Post by: Lowlevldevl on May 25, 2009, 11:58:57 PM

I'm actually more interested in the overall picture. More power, better cooling, more efficient injected engine kills the problem with uneven LOP ops, Gami's even.
I think there might be a few IO-360 powered EZ's about. I believe heat is a problem. Cross flow cylinders might be a simple solution?
What percentage benefit can you expect having the pipes exit close to the hub?

Title: Re: Cross flow cylinders for updraft cooling?
Post by: Drew on June 03, 2009, 07:08:20 PM

I had zero cooling problems with a O320 Longez with downdraft cooling.  Even the oil was too cool---170F.

Title: Re: Cross flow cylinders for updraft cooling?
Post by: dorr on June 09, 2009, 08:54:30 PM

Asked Ronneberg and he said it was a great idea, but he inferred it only comes with the wide deck engines, which are heavier.  He'd like to hear how it goes if anyone does it.

David Orr

Title: Re: Cross flow cylinders for updraft cooling?
Post by: Lowlevldevl on June 14, 2009, 03:59:16 PM

I have an IO-540 B1MD engine in an Eagle agricultural plane. It's a narrow deck engine with the cross flow cylinders. Similar to an early narrow deck Navajo engine except normally aspirated. Those cylinders are angle valved however and I think I read somewhere that they are unsuitable for our canards. Comments?