Airbox Mounting Plate Replacement extra holes

Two years ago while I was looking for something to do I decided to work on the airbox even though I didn?t have an engine yet. As it turned out I drilled the airbox mount plate for nutplate rivets which was a mistake. I didn?t realize that until now that my engine is hung and I started working on the airbox again. Not wanting to mess up an otherwise ?Perfect? airplane I ordered a replacement plate from Vans. The replacement plate I received is identical to the original plate, same cutouts and holes other than an additional 5 extra holes (AN3 size) around the carburetor throat area (actually about 1? from the throat). My old airbox instructions make no mention of these 5 holes and I?m not sure what I?m supposed to do with them. I suspect this replacement mount plate is a newer perhaps more universal plate, I really don?t know. My engine is a vanilla 0320 with a Precision carb and the extra 5 holes in the mount plate don?t appear to be relevant to anything I have. The new mountplate DOES have the 4 holes my original plate had that line up with my Precision carb. I was wondering if anybody that had a newer airbox kit that included this newer style mount plate would also have newer instructions that explained what the 5 holes were for and what to do with them? If they are supposed to be plugged for some installations do they recommend a way to plug them?

Plate

Joe,
I received a new FAB kit from Van's a few weeks ago. The aluminum plate is marked with a sticker and barcode. The part number is VA-130-C-1. I am installing a standard O320D1A with new/reman. Precision carb. There aren't any extra holes on my mounting plate. Only the three big cut-outs, four carb attach holes and the six perimeter holes around the edge. I would call Van's. They will make it right.

I may have ordered the wrong part, darn

Brian,

Thanks for the information. My original part was also a VA-130-C-1 however when I ordered the replacement, the only close number I could find on Vans 'the list' was VA-130-C (no -1), they also listed a VA-130-CF for Ellison carb and a VA-130-D for who knows what. Anyway I ordered the VA-130-C part and that's what I got, probably should have talked to Vans first to see if that was the part I should order. I'll email them and see what the deal is, hate to eat the part since it was $18.63. Thanks again for checking your kit.

An extra HOLE?

647jc said:

explained what the 5 holes were for and what to do with them? If they are supposed to be plugged for some installations do they recommend a way to plug them?

Click to expand...

I should not guess but it could be a mistake! I recall the extra hole issue. Van just said ignore it. How big are the holes, bolt hole sizes right?

The way to plug a hole is lightly countersink both sides of the hole and drive a soft rivet. Than use a rivet shaver (which you probably don't have) to make double flush. You can carefully file, grind, dremel tool the rivet flush. If you can stand a button head on one side, than leave the button. Do not countersink for a full countersink rivet, just an aggressive chamfer, enough to hold the rivet in. If the hole dia is too large and the material is too thin than a plug might be marginal or will not stay in.

That carb airbox plate is a fatigue factory. The engine vibrates and the snorkel part of the airbox, that mates with the cowl via a seal, can really work the metal plate where it mounts on the carb. I highly recommend a little strut from the engine to the fwd part of the air-box. Other wise its all cantilevered out there.

By all means deburr, smooth and chamfer all metal edges of the air-box. It's not a matter of if you'll have a small crack, it's a matter of when. If you do it right you might not see a crack for +1000 hours. If its not right, you'll see a crack in a 100 or 400 hours.

I emailed Vans and they confirmed the part I needed was VA-130-C-1 and not VA-130-C. They said the VA-130-C-1 was a newer part and not in the online parts list however they would be adding it in the next couple days. So, I will return the VA-130-C and order a VA-130-C-1 which should not have the extra 4 holes. Thanks everyone for the input.