Baffle Inlet Ramp-Mismatch with Cowl

Noah · #1 11-12-2009, 08:53 PM

I have an IO-360 (200hp) with Horiz Induction and snorkel, Vans cowl and baffle kit. The front baffle floors (inlet ramps) do not match well with the cowl inlets, which have not been trimmed at all yet. The cowl is fully fitted to the fuse. I'm not clear on the solution to this - the right inlet could be bent diagonally to more closely match the inlet, but this is not possible on the left side due to the air filter needing a flat surface to seal against. Does the rubber gasket fill the gap? I'm having trouble visualizing how this will work. I have match drilled the brackets setting the height of the floors on both the inboard and outboard sides, but I could reset them or get new pieces. After starting on my baffles, I was a little dismayed to learn that Vans does not make a baffle kit for the IO-360 - only the O-360, so there are a lot of discrepancies in the instructions, and they are extremely confusing with several part numbers in the instructions not matching the drawings. Vans support says I'm basically on my own...

N787TR · #2 11-13-2009, 08:55 AM

Noah,

On both inlet ramps a diagonal bend is required to match the cowl (I believe it is in the plans). On the left side, where the air filter lies, it takes a bit of head scratching and a few mockups because of the tight fit but it can be done. On mine, the air filter is located as far aft and outboard as possible. My filter is located so far outboard in fact, that I needed to add a flange on the outboard side of the baffle to accommodate the screws that hold the snorkel in place. Luckily, the filter can twist a bit and still seal very well against the ramps. In essence, the diagonal bend on the left inlet ramp goes across the air filter.

The other part of the puzzle is the snorkel. Most likely, it will have to be modified in order to fit against both the face of the throttle body and around the air filter. Also, look out for interference with the alternator bracket.

Good luck.

schristo@mac.com · #3 11-13-2009, 10:41 AM

for clarity, vans has a baffle kit for the angle valve io360...

RV-7/7A/8/8A w/IO-360 200hp
Part Number = BAF-8-IO360
Price = $275.00

but the instructions are very generic and are not based on this kit... so far for my similar installation i have been using the plans and the engine, without much regard to the 'instruction' sheet, to fit the baffles...

i too am interested in how others have managed this detail. hopefully some will chime in with a photo or two.

Noah · #4 11-13-2009, 01:54 PM

Stephen-

You are correct, there is a kit available, but the instructions are for a different (O-320 or O-360) engine. You would have thought that Vans would make a set of instructions for an engine that they sell and supposedly support, but this is not the case.

I can go back and refit the right side to more closely match the inlet, but there is no way to do this with the left side due to the air filter needing a flat surface to mount to. Given that it is so large, there is just no way to fit a bend in the floor to allow the floor to meet the cowl inlet "lips". Maybe this gap is just filled by a couple of layers of rubber baffle material?

Yes, hopefully somebody can post a photo of this area...

BigglesRV7A · #5 11-13-2009, 02:29 PM

Hi Noah, Just went you a PM.

Greg

Bavafa · #6 11-13-2009, 05:59 PM

Noah,
I have done pretty much the same as Todd, it take a bit of work but it is definitely doable. For the left side, plan the air filter will go as far back as possible.

I believe (if memory serves me right) I installed the snorkel and trimmed it to fit without cutting the baffle for the filter. That sort of set the location for the air filter. The issue that I had was that I did not have as much Clarence in the front to the cowl inlet so I had to trim some portion of the cowl inlet.

Good luck and let me know if I can answer any question.

Mehrdad
RV7A - IO360M1B

Noah · #7 11-13-2009, 09:29 PM

Thanks for the responses so far guys, and for the photos emailed to me.

The problem I have is that the snorkel is already trimmed, the filter frame is already riveted to the snorkel, the baffle cutout is already made, the screw holes are already match drilled and dimpled for the filter retention brackets - basically it is where it is. Without major surgery and replacement of the snorkel ($256), the baffle floor, etc, there is no way to tweak the position of the filter. My mistake was forging ahead with the filter installation without giving enough thought to the cowl / baffle floor interface or doing any trial fits until it was too late. But given the lousy instructions, I'd be surprised if I'm the first person to make this mistake.

So I'm thinking that maybe the solution has to involve a modification involving some fiberglass. If I cut back the lower cowl inlet and replace it with a new layup of a "ramp" which dives from the cowl lip down to the (uneven) aluminum floor elevation, that would be one way to do it. Anybody done this? Or have some other novel solution?

DanH · #8 11-14-2009, 05:01 AM

Noah,
Modifying the cowl will probably create more issues than simply correcting the original errors.

Build it again, using what you learned to build it right.

Bubblehead · #9 11-14-2009, 06:02 AM

I don't want to hijack this thread but noticed something in Noah's pictures that I have been wondering about. In his bottom picture there is a large gap, perhaps 1" wide, between the vertical leg of the baffle and the vertical portion of the inlet. Here's a picture of the right side gap in my plane, complete with dirty thumbnail.

We learned that sealing one end of the ramps on the upper cowling helps keep the air flowing through the cylinders and oil cooler. It seems like this area is another opportunity for air to bypass what needs to be cooled.

I'll dig out the baffle drawings at the hanger today and see what they say, but are my baffles just built wrong, or is there an easy way to seal this area up?

odlee · #10 11-14-2009, 06:59 AM

Noah,

Based on your current dilemma, would it not be easier to pull the brackets from the snorkel and rework the snorkel with fiberglass. I originally cut mind too short and reworked the top portion to obtain a suitable clearance. It has lasted for 120 hrs without problems.(knock on wood,

) I am not sure, but seems as if the cowling rework would become more difficult than reworking the snorkel and surrounding sheet metal. Just another day of building pleasure coupled with frustration!

I will sent you the promised photos late today.

Good luck,
David