water sprayingr and dimond type sight

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don january

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I have been following Paul Lamar's blog's reguarding water spraying the Radiator and I guess the engine internaly of the 13b rotory, Mainly the Rad. during take off. There has also been talk of maybe useing diamond or crystal type of len's for pickup on the ignition inside the engine. One guestion I have, is the aircraft equiped with an extra tank to hold spray fluid ? and if so what is the norm on size ? rotory engine.jpg
 

Voidhawk9

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Just thinking out loud, but wouldn't it be lighter, simpler and easier to have a cowl flap? Never needs to be re-filled, and never runs out during a long climb.
As for a normal tank size, as this would be a novel approach to cooling (at least AFAIK on a light aircraft as opposed to a point-design racer), I doubt there is any 'normal'. You'd need to determine how much spray you need for how long, and how often you want to fill the water tank.
Are you building a cozy like the one pictured?
 

don january

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No not building the cozy, just looking into the new set up's for cooling the rotory engine. Thanks
 

TFF

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If you are spraying an engine on takeoff, you have sized the radiator for cruse only. Takeoff is nessasary so you spray to where speed at altitude does not needed it; essentially cruse speed. Coming down; power is back, so need to augment. Not for shooting T&Gs on a Saturday morning; for a A to B flight only. I bet they spray 5 gallons a takeoff.
I dont understand the ignition question.
 

mcrae0104

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I'm with TFF on this, I'd rather have a radiator sized for the heat load on takeoff and an extended hard climb than a spray system. The only way a spray system makes sense in my mind is if the spray bar system (including the water and/or methanol) weighs significantly less than the difference in the weight of the two radiators.

Also, depending on a spray bar system for engine cooling adds to pilot workload. Maybe worth it for a Reno machine where they're adding a significant heat load to a radiator whose size can't be increased, but for a homebuilt I'd KISS.
 

bmcj

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I like the idea of spraying, but only for a system that has been sized for climbing without spray. The spray then becomes an emergency use item for times when there is abnormally high heat (engine issues or high air temperatures).
 

rv7charlie

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Hi Don,

If your only info source is Lamar, I'd suggest joining the flyrotary email list. They can tell you all about rotary stuff from actual experience, including the use of spray bars.

Charlie
RV-7 renesis fwf in progress
 

don january

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Hi Don,

If your only info source is Lamar, I'd suggest joining the flyrotary email list. They can tell you all about rotary stuff from actual experience, including the use of spray bars.

Charlie
RV-7 renesis fwf in progress
Thank you Charlie I will do that. Never knew there was that sight.
 

Billrsv4

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NW Oregon
Thank you Charlie I will do that. Never knew there was that sight.
The point, well made, is that there is NO NEED to do spray bars with a decent heat exchanger setup. The Best setup I've seen uses 3. 2 water, 1 oil. This plays into the fact that the rotary is 30% oil cooled from the rotor spray. All this spray bar stuff is for racers running marginal inlets for higher top speed or Time to climb attempts. You can fit plenty of radiator in a bottom scoop or even in the cowl if you plan carefully.
Bill
 
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