Baffling???

[PlaneBuilderBill]

To one and all...I've built and re-built several baffles and this one really has me....well, baffled!
Engine: 0-360 A-1-A w/ the standard Dynafocal mount. I set up the cowl per Van's instructions with approximately a 1/8" down offset just behind the top of the spinner to allow for the engine drooping. With this setup, the baffle sides (especially the two adjacent to the #1 & #2 cylinders) have only about 3/8" to 1/2" of metal (This is measured from the valve cover gasket to the top edge of the sheet metal). As the baffle side is mounted to the flat surface of the cylinder, there is virtually no room to attach the fabric seal material! And, this is barely giving me a finger's width of space to the inside of the top cowl.
I've spoken to Andy Duff and he said this is the way his is too (he has actually padded the inside of his cowl in a couple of places to keep the shaking engine from banging into the cowl (metal to fiberglass)...Am I just too concerned or is something sounding fishy???
Thanks in advance, any advice would be appreciated.

 

[Chickenlips]

I know this, the RV-4 cowl was made for the O-320. The O-360 is approximately 1/2" wider at the valve covers and may give you very little room for those baffle sides.

 

[szicree]

Same here. It's real tight but I'm hoping it'll be ok in there.

 

[smokyray]

Dave Anders cowl..

Steve, you might try looking at another cowl if your current one gives you any worries. If I had it to do all over I would still go with an 0-320, but I flew an IO-360 powered RV4 with a fastback and speed mods, cruised at 220 mph indicated (beyond VNE) and had a heavy nose despite moving the battery to baggage. We shoe-horned the IO-360A1B6 into the RV4 using a Dave Anders carbon graphite cowl made for the IO-360. Spendy, but very, very nice and strong.

Rob Ray

 

[Jetj01]

Noticing the same thing...

Bill,

I'm doing the baffling baffles myself and noticing the same min- clearnace thing. I'm using a Sam James cowl which seems even tighter and am concerned. The Sam James is supposed to use a plenum but having one in my -6 is making me NOT want one in my -4. My father in laws new Super 8 is using a Sam James type cowl without a plenum with good success....as long as I can make this fit I'd like to do the same. But with my O-360 A1A it is looking like a baffling challenge....and more busted nuckles!

Good luck!

 

[PlaneBuilderBill]

Pics of Baffle

Took these this weekend....you can see just how tight the top cowl will fit to the baffle sides. I can barely get my index finger between the cowl and the top of the baffle metal.

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I haven't completed the cut-down of the front center baffle material, nor the right front. I'm about half done with it. I'll put some other photos up a little later.

 

[smokyray]

0-320 vs 0-360

I dug out my old RV4 builders manual which quotes "The RV4 is designed primarily for the 0-320 Lycoming, the 0-360 can be adapted with some minor effort and baffling modifications"

Rob Ray