Firewall Forward II
8/28/2005 9.5 hours
Something else we figured out some when Mike was here was the engine harness routing. We tried to route the harness up through a hole in the right intercylinder baffle. I have to say, this route looks promising. Normally on non FADEC engines, I think a fuel line goes here. On my engine though, the fuel line will come through the rear baffle. Thanks Mike!
Unfortunately, I never snapped a picture of this, but I will try to remember tomorrow evening.
Here's the picture I promised. Well, I'm covering this harness stuff in the FADEC pages. Please look there for all the FADEC related stuff.
9/2/2005 13 hours
Here's a bit of a problem... I've got to squeeze this transducer into a tiny space between the oil filter adapter and the secondary alternator. Hmmm. That ain't gonna happen. I'll be needing to find a solution to that. Maybe I can get a right angle adapter drive or something.
The other week, Aart asked me if I could post some info on hanging the engine. So, here we go... It's not too bad really. I can do it on my own now too!
First thing is to get the fuselage level. It's almost an impossibilty to do this with the tail on the ground. Next, tape on the mounts, and put something on the engine mount to protect the powder coat. The stuff is a bugger to get off, except when you don't want it off! Note the mounts. The top and bottom mounts are mounted oppositely, as a different side of the mount is in compression. Check the RV7A drgs, as this isn't shown on the taildragger drawings.
Oooo... Here's the first problem! This one is easy though. You can just drop the engine a tad, tilt it a bit and it'll go under.
Which leads you too the next problem! This ine is a little trickier, but with a bit of manipulation, the hose doesn't have to be removed. Ultimately for final fitting it will need to be removed so it can be routed more effectively.
Once you have the engine offered up to the mounts, the first thing to do is get one bolt in and tightened down. When everything is loose, it looks like it'll never fit as none of the holes line up when the mounts are in their free state. I always do the top left first (from the pilots perspective). This nut is a pain too. You can barely get a spanner on it, you can't use a ring spanner coz once it's tightened down you can't get the ring spanner off because of the pushrod tube. Basically patience and care, and tighten all the way down so the tube inside the mount bottoms out.
Next, you can have a go at putting the other bolt in the top. This requires some pushing and pulling to get it in! Remember I said the holes won't line up? Well, here's your first one. Only two more to do after this one, and they get progressively worse! Fortunately at this point in time, I only need do the top two, so I'll not worry about those pesky lower mounts for now!
9/18/2005 Update
Last week, I got a phone call from Mattituck explaining to me that they managed to fail a couple of the Superior Ryton sumps. Turns out that it cannot withstand a backfire under certain circumstances. Those circumstances are if you're running an electronic ignition system that uses a waste spark (fires two cylinders at the same time). Most electronic ignitions do this, including the one on your car, my car and my FADEC system. Hmmm.
What happens is that when the plane has been sitting, fuel and therefore vapours collect in the intake tracts. When you go to crank the engine, as the spark fires (two of the cylinders) it just so happens that the valve overlap on the cylinder that doesn't need the spark means that the cylinder is open to the intake tracts. Then, the air in the intake gets compresses a little, and the spark goes off and boom! You have yourself a little combustion chamber right where you don't want it.
Well, if you run an electronic ignition, the way around it is to fire it up on the mag, then switch in the electronic ignition once the engine is running. This will clear out the intake tracts. If you run FADEC, you should crank your engine a couple of turns to suck all the vapours through before switching on the FADEC units.
There have been a few failures of the sumps out in the field that we have all heard about. Mostly on tail draggers. It seemed to be associated to sniffle valves being mounted at the front of the sumps instead of the rear. Now that Mahlon Russel at Mattituck has gotten to the bottom of it (pardon the pun) and figured out what the real issue is, we can take steps to avoid such an event.
Now, my question is, does this really affect me? The reason I ask that is because I don't have a throttle body injection system, so in theory there should be no fuel at all in my intake tracts as it's injected directly before the intake valve at the cylinder head. I'm going to call Mahlon tomorrow and run this by him. It may well be fine for me to stick with my Ryton sump.
Right now, Superior are feverishly working on upgrading the sump to withstand this type of event.
Watch this space.
9/20/2005 Update
After speaking with Mahlon again, he said that there's still the same opportunity for a FADEC engine to have fuel in the intakes. Maybe not as much, but there's still a risk. All the other fuel injected engines deliver the fuel to the same place mine does (I don't know why I was thinking about throttle body injection), just that all four injectors fire fuel at once rather than one at a time.
So, looks like if I'm to start mine, I shoudl crank it a bit before firing up the FADEC units. No probs. Hopefully a new sump will be available before I fly.
10/9/2005 8 Hours
I guess it's time to start tackling the baffles. Not the most looked forward to job. First we laid them out on the bench and figured out what bit went where. Then we set about the thankless task of deburring. Clayton worked the scotchbright wheel, and I got into the fiddly areas with a needle file. This seemed to take a long time! Unfortunately, we couldn't try any on for size (on the plane that is!) because I need to order up some screws. I don't know why they don't come in the kit. It would be nice. I'll take some pics of the baffles when I start trying them on the plane. I still had two bits left to do the fiddly areas on when we called it a night.
10/13/2005 4 Hours
I got out of work early today and went to the hangar. I didn't really have a lot to do at work, and the weather was nice. Yesterday, I ordered a 4 into 1 exhaust from Aircraft Exhaust Inc. It looks like a pretty nice system, so I'll look forward to getting that. It should arrive in about 3-4 weeks. I decided to go 4 into 1 because it helps with smoothness, and gives you a little bit of extra power. I don't know how much exactly, but nonetheless more is always better. I think it may be a little noisier than a crossover exhaust, but that what ANR headsets are for!
I continued on with the baffles today. I found the missing bag of hardware (in the box, where else?) and set to it. This stuff is actually pretty good. It practically fits perfectly right out of the box. There are a few small areas in need of a trim, but otherwise, they fit fine. I must admit, I was surprised. Something I need to really get into the baffles, is to fit my cowl. Unfortunately, this ain't gonna happen until the prop arrives, unless I make a pretend spinner. I'm not sure I want to risk that though, so I think I'll just wait until the prop is here. It shouldn't be long now!
Here are the baffles in place. I even managed to get the right rear baffle on without removing anything from the engine!
The only real problem area I've seen so far is the rear right corner. The jog doesn't jive... In the end, I did what other people have done here and cut the offending flange off. I'll replace it with a piece of angle.
This is pretty much where the oil cooler will go. I really wanted it on the firewall, but the FADEC has eliminated that possibility. Oh well. As long as the baffles are well braced, I should be OK. I also need the cowl in place to figure out how high I can mount this thing.
Next up for the firewall forward stuff today was the starter motor. I'm using a snorkel inlet so I don't have a scoop on the bottom of the cowl. Unfortunatley, the starter motor has some ears on it that interfere with where the snorkel runs. Need to cut these puppies off!
The lug closest in the picture is fine. That one is for the alternator mounting, so it's not going anywhere. The problem child is by the terminal there.
Here it is, all chopped off. It clears nicely now.
10/22/2005 4 Hours
I dropped Lucy off at the Airport for her business trip this afternoon, and then went down to the hangar. I started to work out the throttle bracket, since I got my 4130 steel I ordered form Spruce. I started by making a cardboard template to kind of get an idea as to where I was going with it. Once I was happy with that, I had a go at making it out of steel. Well, I haven't got a bending brake, so I tried to bend it in the vise. The results were poor at best. So, I called Mike to see if he was going to be home, and he was, so I headed out there to use his tools!
First off, I drilled some holes in it where the bends would be about, to relieve any corners. Then I trimmed the shape to about what we needed on the bandsaw. Next up was to try to bend it. This actually worked out pretty well! We had to make one bend using some hand seamers, but it also turned out well. Fortunately, the length we had to hand bend was pretty short.
Once we had it all bent up, I wanted to weld along an edge to form a corner of a box and give the bracket a bit more structure. Mike has a MIG welder, so we made up a few practice pieces first and had a go. Well, I'm not the best welder, but I picked it up pretty quickly. For this material, we needed both the wire and the current set to their lowest settings. It was hard not to burn through the 0.050" sheet, and also fill the gap I had to fill, which was about 1/8" maybe a bit less.
After I was happy with the practice shots, it was time to do the real thing... Here we go! It turned out pretty good! Sometimes I even surprise myself! I certainly surprised Mike! He thought that since I was only welding for a few seconds that I'd surely screwed it up, but no! All was well! It needs dressing up some, but certainly not too bad. The main thing here is getting good penetration, and no voids.
Here's the rough bracket. Tomorrow at the hangar, I'll trim it to it's final shape and try it for fit on the plane. You can see, I need to file the relief hole a bit to clean up the end of the weld, but other than that, it worked out nice.
Looking at the picture, the bent up tab is the front of the part, and there will be a hole here that attached to the lower right stud of the throttle body as it's bolted to the sump. The foled wall at the back of the part will have a hole for the cable. The closest horizontal face will attach to a boss on the bottom of the sump with two more bolts. When it's all shaped, lightened and drilled, all will become clear.
While I was at Mike's, we had Pizza. It was good to visit, see Ella and Jill, and meet Mike's Mum. Thanks for letting me use your stuff Mike! Oh, I forgot to put all the bits of the bending machine back together after I took it apart! Oh by the way, it was a 100 mile round trip from YIP to Mike's, then back home to Dearborn!
I continued on with the throttle bracket today. First I put the holes in it, then went on to trim out it's final shape. It turned out really neat. Here it is on the plane for the first time. I trimmed the first hole around the throttle body mounting. Next was the holes to the boss you can see on the sump. Two bolts go in there.
A close up from a slightly different angle.
Here's the final trimmed up part with the throttle cable in there too. This isn't the final assembly though, as it all has to come apart again for paint.
That was it for the throttle bracket. Next it was time to move back into the fuselage to do some fuel pipes. Ugh.