I was wondering if this looks like I have enough removed from the dummy radial for proper ventilation. Saito FA125a is the engine.

Oh and does anyone know of any tricks for rerouting your muffler other than the expensive ass extensions they make?

I would say that is not enough, but if you have it routed over the cooling fins that helps.

Rule of thumb is 2X more exit opening than intake.

No where near enough. Common and effectice practice with radial engine cowls and dummy engine cylinders is to cut away most of the dummy that is directly in front of the real cylinder.

Even more important is to let the air out at generally twice the area than the inlet. This is usaully positioned at the firewall on the underside.

Far two many nice scale planes have been lost because the owner would not let the engine compartment breath so the engine could be cooled.

John

Bob,
What I've done with those is trim the areas between the dummy engines, 2 bays should be enough,, that gives you more air in,, then like other say, make sure you have enough exit. Having the cowl flaps open is a easy way of achieving that too, not sure why the ARF Man.s don't design them that way.

good luck

that's not enough, you should make it for two times of this space

And don't fpr get to have a small ait dam at the leading edge of the out let to create anegative pressure, and pull the air thru the cowl

Cheers Bob T

Is there any reason I should not install the Kwik Fill Valve inside the fuselage by the gas tank? I don't want to drill holes in my cowling and since my plane has such easy access to the "storage area" I figured I would install it in there.

Put the fill dot/fitting anywhere you like. If it is on a klunk for draining the tank you might want to place it higher than the tank fill level if possible. Not usually a problem - but if you forget to leave it plugged it can dump fuel on the ground. This one has gas just ahead of the smoke fill and the vents down below. Works great.




This one is on a block behind the muffler. Clean, but watch your piddies.




I installed this one below the cowl (along with the kill switch and the vent) and it's kind of a pain. Has a servo kill switch inside as well. Again, clean, but at a price. I splii a bit but at least it's not on the model.

Yes,, they suck,, they work nice at first but will fail on you sooner or later,,, use the fuel dots and a "T" or a 3 line system,,, you'll be happy you did.

Also reguards to the cowl, typically it easier for maintance if you can mount them to the fuse side, it's a pita to snake the lines sometimes through the cowl openings when you're taking it on/off,, but nothing wrong with mounting it there if it's the best spot for your app.

good luck

Yeah I meant if mounted to the front of the fuselage under the cowl, drilling a hole in the cowl to epose it. I have never had a problem with my Kwik fills. Except for when I pulled the planes out of storage after 12 years. I just put some oil on the o rings every few months and it seems to keep everything working well.

"Yes,, they suck,, they work nice at first but will fail on you sooner or later,"

Usually caused by just pushing the connector straight in and out. If you lubricate the probe and rotate it slightly as you insert it, you will eliminate that problem.

Les

I've never had one that didn't fail after a couple years, you guys like them thats fine,,

These never need lubing and ya never have to worry about loosing the probe,, oh and they are a lot less expensive


Nice having choices

Can go just about anywhere ya want I guess,, When I did use them, I liked to mount them where they'll stay cleaner, inside a cowl wouldn't be my choice

good luck