Posts by Dave Berenholtz

Date:  07-01-2024

Number of Hours:  30

Manual Reference:  23

After a mega amount of work I was closing in on my goal of engine start by 30th of June 2024.

The engine was looking good, I had lots of wires and fittings nailed down and then it was time for a pressure test.

After my pressure tools failed I adapted the leak down tools that were in the hangar with various fittings. Initially I found a few of my hose fittings needed to be tighter and I kept chasing down pressure drops until things were looking OK.

I’d bought this coolant test and suck kit online. As I said the pressure part failed and I adapted. The other function is to use the kit to pull a vacuum and then suck the coolant into the system. The idea is to avoid air pockets by filling via a vacuum instead of just pouring coolant in and hoping it works out.

Here’s the procedure with this tool:-
Setup: Compressed air line in next to the orange valve, Coolant ‘suck’ line is opposite the gauge at the bottom. The blue line goes out to the special radiator cap.

1. Turn on air valve left side of gauge
2. Orange knob to allow air in
3. Once pressure gauge is full with air in, we suck a vacuum
4. Air valve off, orange valve off, we now have a vacuuum
5. Coolant line into the container
6. Open the valve to suck the coolant in

Not the simplest process but it works and I sucked all the coolant in without too much mess.

Then the bad news. I had a significant leak at this water fitting.

I also had a very slow leak at this Welsh (or freeze) plug. It had to be fixed.

After quite some hours we finally got the Welsh plug out. The cylinder had a lip behind the plug so the usual trick of rotating it like a middle hinged door was not going to fly. It took grinding and heroic measures to remove. It seems there was a bit of an issue made when it was installed and I got to be the recipient of that perhaps less than careful work

The other pipe leak had a pinched O ring. This was possibly caused by the engine guys installing one side and then the other would have to go in at an angle. Its a tiny O ring and it didn’t make it.

After the old Welsh plug was out I bought some new ones locally. Then I annealed them with a blow torch that was in the hangar.

I did a bit of research and found a suitable sealant for the job. Its no picnic trying to install these things cleanly. As this cylinder design has a lip it is very forgiving.

Now the secret of installing this guy is to take off exhaust pipes and induction for access and just put the unit in as one. That works a treat, it just slides right in.

After another pressure test, we were good.

With these two leaks sorted out I put coolant back in the plane…again. 6 Liters covers it by the way. So far and some days later, no leaking.

Date:  06-23-2024

Number of Hours:  20

Manual Reference:  23

First engine start, in the airframe I have built is getting closer. A first step was to see if we had oil pressure now all those lines were in place.

OK, not the most exciting video. For me putting 8 liters of oil in the engine is a milestone.

With that W100 oil in the engine, we ensured the top spark plugs were out so we had no compression. Then we used the starter motor to turn the engine over, with no load, and we waited to see that we had oil pressure. Yes, oil pressure, we are good. So on to the next step.

The wiring in the hellhole has been monumental. My un-named avionics guy is doing a fantastic job in this hard to get at place.

For many months this has just been a jumble of wires.

I mounted the two water pumps in here some time ago but of course they are out to get this cable work done.

We have a shunt for each alternator and that earth tree. You can see the HF antenna tuner as well upside down on the ‘roof’.

Here’s an engine overview as I’m sick of being under the plane on that creeper.

Now with the pumps in things look even tighter.

Yes, not a lot of space left.

Here again you can see whats going on.

Date:  05-27-2024

Number of Hours:  20

Manual Reference:  23

Given I was never happy with the RHS radiator duct, it comes as no surprise this needed more work. I had moved the radiator mount yet again by a small amount, less than an inch, but that was again enough to interfere with the cowl. It was also too much of a gap from the cowl armpit intake and the mouth of the duct.

To fix and modify I just cut a big chunk out of the duct and the plan is to stuff it with some foam and rework the shape.

There is no need for a perfect plug to begin with. I’ve added some pour foam to fill the gaps.

Now the fun part, lots of shaping, lots of putting it in place, putting on the lower cowl and then carving a bit more.

I’m getting closer here.

More carving and checking of position.

More checking.

Its looking pretty good now.

I did the usual thing of thin plastic duct tape for ‘release’ and modeling clay for filling holes and the transitions. I needed to think about making a gap between the release tape and the old carbon structure. I didn’t want plastic tape trapped under the new carbon between the old stuff.

The usual three ply and carefully wetted out on plastic. The pic above is the prep before wetting out the cloth.

OK, three plies done. Its a weird shape to get the cloth to sit over. I use my gloved fingers and patience to work it into position and then trim the edges with scissors.

Getting these things off is always fun and takes a little time.

After the big clean up here we are.

Another angle. Its very smooth on the inside too.

Here are my two radiator ducts. The next step is to somehow work out a way to transition these when back in place to the removable cowls. I don’t know how yet, I just have a few ideas to try. Sitting and staring at the job also helps.

 

 

Date:  05-29-2024

Number of Hours:  10

Manual Reference:  23

Since building this door it has been pointed out to me by a particularly knowledgeable expert that there are issues down the track for CF and aluminium. I’ll omit the names. Here’s what he said when I asked for what I should do in this situation i.e. I need the strength of rivets in my carbon fiber structure to join parts with a hinge.

“…when I built the CF ailerons for (name deleted), I layed a barrier ply of very fine fiberglass cloth over the aluminum inserts for the hinges, and then used monel “pop” rivets to install the hinge halves to the ailerons. I determined this to be the best combination given the galvanic series in play. One can install squeeze rivets wet with a sealant (e.g. Proseal) and wipe off the squeezeout, in order to better-isolate the aluminum from the CF, but this is still a crapshoot, as end-on CF fibers can still impinge into the shanks of the rivets.”

I didn’t know what a monel rivet was so here’s a google result

“Monel” refers to a group of nickel alloys that provide enhanced capabilities to withstand conditions that other materials cannot. Monel rivets are commonly found in aerospace, marine, and oil and gas production/refinery applications, as well as in high end musical instruments, among other uses.”

Ok, back to how I did this without the above variation.

I got the rivets in the hinge OK. The door didn’t quite close as well as before. I just bent the curved section of the hinge and it settled down again. Despite being really careful, this is a moving platform.

Hartwell H-5000-2 The 0.91 might refer to the height of the tongue in relation to maybe some other bit of this fancy mouse trap aka finger trap. It’s a standard GA part apparently.

I was going to use a smaller push button hinge that was tidier and required much less force. I just wasn’t happy with the striker plate arrangement on that one as it seemed quite marginal to me. The slightest shift and the door might pop open, or need resetting. So this monster is going in.

I stumbled around trying to envisage how far from the lip this should sit. In the middle and back a bit seemed like it would work for putting in the striker.

It is always a bit scary to cut into a nice structure. Yes I’m working at nights as well as days now. 7 days a week trying to get this thing done.

I found I had to get the hinge lower to match the striker position. I was also dealing with a curved surface and if I just clicoed the hinge in place the door distorted enough to ruin my nice fit. Here I’ve gone with four plies of CF, then trimmed the edges after cure. Next I laid a bed of micro to get a really perfect fit for the latch. I guess I got a bonus of isolating the steel from the carbon to some degree.

I used tiny screws and nuts for this micro cure as I didn’t want to distort the door. It still did a little but at least I put in the effort. <grin>

To my surprise the door with the spring in the hinge is so powerful that it straightened everything out and it sits really well. Who knew? Next up was a striker plate. I’m using chrome moly for its strength and I did prime it well as that stuff rusts as you look at it.

I also needed to embed the striker to match the tongue. Too far and the carbon thickness would have been compromised there. If I’d made the hinge any deeper if would have looked pretty bad. So it was a juggle between the two. Of course if the hinge was a different spec I may have been better off. The supplier doesn’t give that option.

The final rivets went in. I used the ‘soft’ type and they really improve my riveting!

The striker was glued and riveted. It is thick enough so I can thin it out just a little if I want to get a stronger latching. I’m happy enough for now.

Here’s the hinge in action. In practice I’m not going to let it spring open so violently. I’ll need to develop a technique that is also safe for my fingers. The big deal for me is that one door allows me to service both oil and coolant.

I will make the fit perfect when its time to prep the cowl for painting. It’s not too bad now and time to cross this job off the list.

 

Date:  05-19-2024

Number of Hours:  4

Manual Reference:  23

The oil door is one of those side jobs useful when I’m waiting for a part or some other hold up.

I’ve added a piece of 2024-0 so its bends easily give the cowl has a great curve here. I’ve just epoxied it on to form a strong lip.

Next up was positioning the hinge and door with hot glue to ensure I have the geometry correct.

It seems to work OK with the door allowing good access.

Next up was to drill a few holes and add clicos to again ensure the door is opening and closing OK.

I found the four clicos distorted this hatch too much. I’ve just gone for one each end and after this pic I’ve added some micro slurry to ‘add in’ to the middle curve so that the hinge and attached door rests on a solid support.

The door seems to work OK now and it will only need a small amount of filler to make it flush.

The next step is to add a few soft rivets after the cure, as you can see this is now done.

With the edges trimmed it is as wide an opening as I can make for this size door.

As you can see it has quite a spring which is what I wanted. A strong opening so its one or the other… and inline with the airflow if I ever forget it.

 

 

Date:  05-19-2024

Number of Hours:  18

Manual Reference:  23

If I find myself stuck waiting for a clearance for with the engine running, I have concerns that things may get too hot. Being a pusher I don’t really have good flow through the radiators until the plane is flying. The possible solution is a small fan on each side. When at idle revs I hope this will keep things under control.

The fans rotational speed and when they operate is automated, just like it is in a motor car. I don’t need a manual control, just like we don’t in our cars. The temperature sensor will talk to the fans and the water pumps too and the device will work it all out. All I have to do is set up the controller to some preset temperature.

While there is an optimum place for each fan that I had in mind, reality told me the only places they might fit. As it was I had to move an oil line which required replacement.

Each side was marked with the footprint that fits a fan and in what orientation.

Pretty simple really.

How to mount these things has been on my mind for months. It turned out to be simple, in a way. I have gone for 2024-T3 to make the fittings.

It turned out to be some 90 degree angle and an offset strap.

With these offsets I can position the fans exactly and the fasteners don’t bump into each other. Yes I did change the nuts to locking nuts later. This is just for the setup.

I can set the height of the angle pieces exactly and then my plan is to very carefully rivet them in place. After that it can be welded properly. This time things will be exactly where I want them rather than trying to fit in with however the welder ‘places’ it.

It might be clearer in this picture. The next step is to get the pull rivets in place without penetrating the radiator flow areas.

I made a little drill stop but it was still a scary process. One slip and I have a leaking radiator.

Each fitting now has a couple of pull rivets. These have positioned the fans exactly where they need to be ready for welding.

My slightly strange solution is now in place.

The next step is the welding and then I can remount the radiators. They might need a little trim around the exhaust pipes and perhaps some thermal shielding.

The welding was pretty poor but it will hold. I cleaned things up as best I could. I’ve since trimed one of the fan shrouds so it fits better. I might add some shielding later.

With the fans done I went back to other little jobs. Some nut plates needed moving on the filter box and with that done after an hour or so I installed them back in the plane with the weird idea that they are done until engine start.

You can see some of my lists in the background here. I keep crossing things off and adding more.

 

Date:  05-15-2024

Number of Hours:  20

Manual Reference:  23

Not a lot of the hose saga has been documented in this blog. I have been buying fittings for the last couple of months and trying different combinations to do the seemingly impossible task of getting the water and oil system completed. Here are just s few little tastes of what I’ve been up to on this one.

After numerous tries, this combination is going to work. I wanted to just connect a Tee to the water pump input  from both radiators but I found there just wasn’t room. So I’ve had to come out of the pump go to the right and then have the Y join from the two radiators. The pump will just have to suck it up.

Here is that arrangement in position ready for me to make up the hoses. You might agree this is pretty tight.

The hose on the bottom is the output line to the Laminova heat exchanger. I had to change everything form a AN-16 to AN-12 because that bend in the pipe was impossible with the heavier and thicker OD hose. That cost me several hundred dollars and a lot of time including a replacement end piece shipped from England.

Here we go out of the pump input to that Y arrangement all because there was no room for a Tee. Does this make sense?

Here’s a wider view.

Now this was interesting. I had to get the breather outlet to the prop end of the engine. Its is a huge 3/4″ ID pipe and I’ve covered it in fire sleeve to hopefully stop condensation. I’m still ‘negotiating’ the exact position. You can see a top hose going to the radiator with an ‘S’ bend in it. That required several ties at various angled fittings. What you see here was not the final configuration.

This was a fun one. I have to move the oil line that was all finished to fit the radiator fan I’m adding. The oil line worked out about an inch and a half too short. So I had to go and buy more hose and more fire-sleeve and remake the hose. When I pressure tested it to 1000psi one fitting was leaking. My fault or the fitting? I went and bought a new fitting ($62) and no more leak. Of course I used a new olive on the other end.

One reason for making my own hoses is exactly this scenario. To make items fit and play nicely together sometimes means I have to rearrange, remake and change hose length and fitting angles.

I might mention a couple of nights recently in the hangar just on wiring after i put in a days work on other things.  You can see quite a confused mess as I laid out the two System 32 engine and fuel looms.

After a lot of time, simplicity reigns. My very able wiring guy worked out the runs and we made decisions a few nights ago. New ends are on order and we will reuse some of the original fittings as well. All the protective sleeves were replaced with much better, smaller and more flexible tubing. The result will be an elegant layout, clean and simple, for easier maintaining and troubleshooting.

Date:  05-11-2024

Number of Hours:  15

Manual Reference:  23

While I already have an expansion tank, I also want an overflow bottle. The expansion tank is a little small at around 1liter and I think I want a greater margin, the extra is another .8Lts or so I think. With a small bottle I can more easily top up as required, visually inspect without removing the cowl and prevent fluids going overboard if I get too hot.

The main aluminium expansion tank is pressurised and has the radiator cap. If the pressure gets above 1.2bar, or about 17psi, the cap pops slightly allowing fluid into the overflow bottle. As the engine cools down the fluid is drawn back into the system and the valve at the cap closes again.

This is the third bottle I have purchased. <sigh> I just couldn’t get the other ones to fit and this at least is a proper Rotax bottle so I know the plastic is OK for under the cowls. The other ones I bought were automotive so just as good really. Let me know if you need a weirdly shaped vessel.

Somehow it needs to fit here. Kind of suspended in mid air, exactly positioned so it is very close to the oil filler but not touching. It also needs to be accessible from the oil filler door, not too high or too low and not interfering with adding oil either. Oh, and easy to fill via that door too.

This is the idea.

OK, its not that pretty. Be nice, it took a day of head scratching and thinking to design.

Here’s the idea. I’ll support one corner with a hose clamp on the engine mount. This smaller bracket will take up a little of the weight of the bottle and fluid and stop it wiggling around. The main support needs to be from the top.

I started with some mock ups, again after thinking of a lot of options. Staring and thinking is my modus operendi followed by more of the same until something to try feels right. The plan is to suspend a plate from the underside of the cowl lip and cable tie the bottle to that. Because the lip is curved I’ve needed to go for two brackets on weird angles with exact bends in the supports facing onto the flat plate.

Here’s the idea in practice.

Now you can see if I strap the bottle to the plate and have it also supported in the lower right corner, it should work and be where I want it.

I had to make a lot of brackets to finally end up with these two. I thought I was doing the right thing using really strong 2024-T3 aluminium and bending them, but I kept getting cracks. After three sets failed I took a break and did some reading.

2024 is not really recommended for bending. Three series or five series is the go. 3030 seems best but I  found some 5083 and I was very careful to get a nice wide radius bend using the big brake in the hangar.

Then I went and made them small to save weight. Doh! I should have sized for the nutplates first and I made an easy job very difficult. I’m learning something every day as well as making brand new mistakes. I still got it done.

After a bit of a clean up its not too bad. I added the holes to reduce the weight a little. The slots are for the cable ties.

It is not so pretty around those rivets. I had an ‘interesting’ job getting it done. Next time, rivets first, trimming to size later.

I had to pull the radiator out to secure the lower bracket. It seemed a good time to add some fireproofing to the cowl pocket. I was leaving this in case I needed to introduce some extra cooling air but I have changed my mind and is can be removed later if necessary. I still have to do the other side next time that radiator is out.

Here’s how the bottle is supported from the bottom with that backup bracket.

From the top the bottle is very secure.

You can see ‘we’ have met the brief with both fluid items accessible via the oil door. I still have to install the hinge and fastener for that too!

This shows how tight things are in that corner.

Finally a bit of an overview. I just have to add a bit of hose and this part of the water circuit is done.