Friday, December 23, 2011

A short day

I was skipping ahead when I started into the deconstruction and (ostensible) reconstruction of the engine - there's actually some on-airplane work to do before that. This on-airplane work involves the installation of the electrical and electronic components that support the engine. The complexity of the components runs a century-wide gamut, from the stone-age starter relay all the way up to the solid state manifold pressure sensor for the Dynon computerized engine management display.

Today, though, it matters not how complex the innards of the components are; they all get bolted to the firewall the same way. How hard could that be? [Ominous foreshadowing organ music here...]

The weather was in the low 40's, which is cold in my current pre-acclimated state, but will soon be considered balmy. Once we spend a few months in the 20's, the 40's are going to feel great! I figured I'd have Pete come down and we'd get all of these pieces/parts installed before the weather realizes that it's officially winter now.

The electrical cycle starts at the power source which in this case is an Odyssey gel cell. Put it in the box and bolt it down:

Then the master relay gets bolted in. Two bolts, two washers, done. Nothing instills what will ultimately be proven to be a false sense of confidence like a part that fits right in, no pushing, shoving, trimming, tweaking, or swearing required.

The starter relay looked at first glance to be just as easy, albeit with slightly smaller bolts. Such was not the case: the holes don't align. The hole spacing on the relay is 1 11/16", the hole spacing on the firewall (mine, anyway) firewall is 1 7/16":

This was a real poser, but fortunately Van's tech support was open - I made my first ever call to them to get this resolved. This turns out to be a well-known problem. So well-known, in fact, that the tech person at Van's was shocked, shocked that I was just now tripping over it. Solved years ago, it was, through the expedient of mailing out an adapter plate and a sheet of instructions for everyone that they determined needed it.

I don't think I ever received one.  I told him that, but I get the feeling that he didn't believe me.  He could be right, of course, given my propensity for losing things that I sock away in the interest of "not losing them."  Either way, there's one in the mail now.  One of the things Van's is really good about is sending replacement stuff quickly (and at their cost!) when things like this come up.

Not that there's any rush; the lack of the adapter plate didn't really require that we stop work, but I was already getting cold, having failed to dress appropriately to the season, and was quite happy to call it a day after only an hour. I did go ahead and install the engine ground wires. I was more than a little surprised to see a wire this critical to the operation of, well, just about everything attached with a tiny little bolt and an even tinier nut, hidden well behind what will soon be a large oil tank. I was very surprised that a nutplate wasn't used, given the inaccessibility of the location. I hope I never have to remove this thing! It's possible (or likely, even) that a nutplate wouldn't provide a good enough ground.

Here is the instruction page for the adapter:


Torsten said...

THIS is supposed to be the ground connection for the whole system???? You gotta be kidding me! No wonder I've seen so many electronic issues on the VAF that eventually got traced down to ground problems. This is not best practices!
On another note, could you give me the measurement of the distance of those two bolts holding the starter relay? I want to see if I need the adapter plate as well, as I know I have never received anything outside of the kit from Van's.

DaveG said...

The holes in the relay are 1 11/16", the holes in the (mine, anyway) firewall are 1 7/16".

Anonymous said...

Dave, I have the new version firewall also and had the same issue. The Vans transfer plate pushed the starter contactor into the rudder support bracket, about a 1/4 inch lower then the position in your photo.

Anonymous said...

Based on forum posts, I ran another ground wire from the engine to this place. That has solved other folks electrical gremlins. There are unused threaded holes on the top of the cylinder heads that take an M5 metric bolt. I ran from the nearest to here, easier to do now. Bill H.

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