spinner or no spinner for better cooling?

[ryan_m]

Spinner received this afternoon, so I got it all cut and mounted a few minutes ago. Looks great. Definitely a fan of the No Limitz spinners!
Now hopefully the weather holds for the weekend and I get to see how much difference it makes in the motor cooling.

 

[Naughty Monkey]

Looks great, especially for using that skill saw by the delta wing.

 

[stangflyer]

Spinner received this afternoon, so I got it all cut and mounted a few minutes ago. Looks great. Definitely a fan of the No Limitz spinners!
Now hopefully the weather holds for the weekend and I get to see how much difference it makes in the motor cooling.

Nicely done Ryan.... very nicely done!

 

[ryan_m]

Well the spinner helps, but not quite as much as I had thought/hoped it might. I still saw temps range up to 325, but not any higher. Previous I could see it get into the 340 range. I did notice that it didn't heat up as quickly though, moves that used to pop the heat up into the 330+ range in 10 seconds would now take an extra 10-15 seconds to get there. So it helps for sure. Drops the temp about 15-20 degrees I would say.

 

[Naughty Monkey]

Should be golden! They say 20-30 seconds is all most people's maneuvers last anyways.

 

[Bunky.F.Knuckle]

Try to get the engine cylinders closer to the front of the cowl. Its all an experiment. My Yak 55M had the engine set back a little, much like yours. When I put the new cowl on the airplane, it didn't come with a dummy engine, like when it was new. Just decided I was gonna pack as much air into that cowl as possible!

 

[Naughty Monkey]

do you have any baffling inside the cowl? Even extending the bottom lip of the cowl/dummy engine opening to about the center of the cylinder will make a huge difference. Also, if you move the engine forward it will move the prop away from the cowl which also helps with airflow. If you look at the full scale planes, the prop is way out in front of the cowl.

 

[stangflyer]

do you have any baffling inside the cowl? Even extending the bottom lip of the cowl/dummy engine opening to about the center of the cylinder will make a huge difference. Also, if you move the engine forward it will move the prop away from the cowl which also helps with airflow. If you look at the full scale planes, the prop is way out in front of the cowl.

Something like this is what you want for round cowl motors.

 

[ryan_m]

Baffling currently goes back to almost the cylinders, about 1.5 inches or so. It was as much as I could do and still be able to work the cowl onto it. It's a completely enclosed baffle, all four sides, so the air will go as much as possible onto the cylinder head.
The plane is already a touch more nose heavy than I would like, and I can't really move anything else around inside of it to change that very easily. So moving the motor up another 3/4 inch will make that problem worse I think. But it may help with cooling... right now the temps are ok with it, no fades on uplines, and running within what everybody said is good given where I have my temp sensor located. I'll keep monitoring it as the summer heats up here. If needed I'll get some longer stanoffs and move the motor out a bit more and see how that changes things.

 

[Naughty Monkey]

Sounds like you got all your bases covered. If you can get at least your bottom front baffle right up to the cylinder, about midway up, that will help. Also make sure you have a good exit opening with a lip in front of it to draw the air out. This can be as or more important as anything else to keep your cool.