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Baffle problem with IO-320

chris mitchell

Well Known Member
Not sure which forum this belongs in, but it?s an RV-4 so here goes.
Trying to install the baffles on my IO-320 D1A. Maybe it?s a funny shape but I am bemusedby the rear baffles.

The rear baffle on the right behind cylinders 1 and 3 went on fine with a small amount of trimming. It sits more or less as I would expect. The left side - behind cylinders 2 and 4 has me scratching my head.

The outer section went ok, again some trimming but not too dramatic, and it sits nicely with the side baffle around cylinder 4. The inner section needed a lot of trimming to fit round the rubber of the top left engine mount. In the centreline the bit on top it sits about 3/4? behind the equivalent bit of baffle on the right.

I could just take the left one over at an angle, which offends my need for straight lines and right angles. I could bend a dogleg into it. Or maybe I?ve just completely misunderstood the instructions, tho it wraps nicely around the cylinder and mates appropriately with the lateral section.

What am I missing?

Thanks

Chris
 
Photos

I'm not quite sure I understand your issue. I looked through my various photos and have two that are almost overhead of the left side. One is a little out of focus. I can email them to you (?).
 
My baffles on my -4 with a 360 were a bit off but opposite. The left side is behind the right side my .5" or so. I put my left baffle right up against the engine ear not back on the rubber mount. You have a picture you can post? That's a Dynafocal engine right?
 
Not sure if this helps but here are two quick pic's I could find of mine.

2hpodpu.jpg


zbv9s.jpg
 
THanks for the photos, which are helpful. Brian could I see yours please as well? Yes, it is a Dynafocal engine and mount.

The left side baffle is behind the right, by 3/4 inch. The lower part of the engine case, where the baffle is secured, is cut away to about 1/4" thickness whereas the top part, where the engine mount comes through, is about an inch thick. If I use a spacer - as the plans suggest, it needs to be 3/4", not the 1/4" the plans call out, and then the portion that wraps around the cylinder doesn't fit without a lot of bending, and even then doesn't sit nicely.

Although the engine is (nominally) a D1A, it is a rebuild and I have no idea what aircraft it came out of. So maybe I have a somewhat odd engine case based on its original applicaation..

Interestingly, the baffle support bracket fits on the back, not the front.

Here are a couple of photos of where I have got to. As you can see, I have opted to mount the baffle right back against the case - which seems to give the best fit. As a consequence I have had to cut away to fit around the engine mount, and put a dog-leg bend into it to get the medial extension to line up with that of the right side. I plan to add a strip of metal along the bottom of the left side to butt up against the top of the engine case.

If this setup seems to work I'll go with it. If it doesn't I guess I'll either be rolling my own new part, or getting a new part from Vans. It all seems quite odd to me. I know baffles often need to be "personalised" but this is the first time I've had such a significant deviation from what the plans call out.

Not sure what I've doen wrong here - cpoould someone please edit as needed so the photos appear? THanks

https://imageshack.com/i/pobNCTjRj]https://imagizer.imageshack.com/v2/1280x1024q90/924/bNCTjR.jpg

[url]https://imageshack.com/i/pnGNM2ZKj][/url][IMG]https://imagizer.imageshack.com/v2/1280x1024q90/923/GNM2ZK.jpg
 
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To me it looks like you have that rear left (center) baffle pushed back to far, is it wrapping around the cylinder barrel? Also looks like that outer left baffle is pushed off the cylinder head fins? that baffle should be perpendicular to the fins and yes the bottom wrap around piece takes a lot of pull forward with the rods to keep it tight.
 
Oil cooler location?

Keep in mind, if you install an oil cooler behind #4, that will require some custom work. I have an O320H2AD engine, which isn't like any of the other O320's, so my entire baffle build was from scratch. I mounted my oil cooler behind #4 on L/H side and also added support tubes, ect. I have lots of pictures, but can't load them to VAF easily from my device. I kept all my lines "squared" as you suggest you are trying to do. Send me a PM with your email, and I can get you some pics.
 
Thanks for fixing the pictures Shawn

I understand the point you are making, but, yes, both bits of baffle are right against the respective bits of cylinder finning, and both are perpendicular. I'll go and play some more. Getting a bit frustrated by my inability to get this part right!

I was going to hang the oil-cooler from the engine mount, behind number 4 with a hole cut in the outer baffle and some scat tube to direct the airflow through the cooler. I'll need to fashion some mounts and bracing.
.
Bill - I sent you a PM with my email address. Thanks.

As ever, thanks for help guys.

Chris
 
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Looks like you have the older (pre 2000 or so???) version of the baffle kit.
The latest version has a wrap / curve in the inboard (steel barrel portion) of the left side so that the upper portion can stay aligned to the right hand (cyl 3) side.
 
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