Swapping over engines

I have been working rather tirelessly on this conversion. Pictures never portray the hours of work involved with these things but hopefully if someone ever does follow this in the endeavour to do a conversion like this they will gain a decent appreciation of what took place.

I've been a bit worried about the plane being tail heavy when I finish so I have moved the motor forward about 22 mm or 7/8 " forward for you gunslingers who still use the imperial system. Hopefully with the weight of everything installed like the oil tanks, radiators and so on, plus moving the engine forward, it will enable to me to keep my existing long range Aux tank behind the seat.

The engine was test fit onto the jog just to see how it would attach to the original Aerovee mount.

For a while there I thought the mount may have been able to be incorporated into the new engine fitment. I did try to use bits from the donor plane mount and the original mount and do some sort of grafting onto each other but it soon became apparent that this was going to be a foolish idea and we needed to basically start from scratch.

We did keep the section of the mount that retained the landing gear legs and so on but all the rest was cut off and we started planning the new mount.

I bought a healthy amount of chrome moly tube and we set to work. The bonus of the engine being in the exact right spot enabled us to make the mount piece by piece and allow for the starter ,carbs, hoses and ancillaries, giving them ample room while sticking to the design plan we all agreed on for strength.

The last picture is the engine mount all basically tacked together before it was removed for final welding and painting. The actual engine attach points were retained from the old mount and the rubber bushings also used. It worked well on the previous engine so we stuck with that method.

And so it begins

Well I haven't been mucking around in regard to this conversion. I have had a bit of help for all the planning and so on behind it. We had quite a successful weekend and it's sort of in place on the Sonex.

The jig is basically there to keep the prop hub in the correct position as per the old hub. A friend had also made up some spacers I could use to allow the engine to come forward or backwards via shims and to be able to position it correctly for the weight and balance. We’ll see how that all works out. 

So it looks like the Aerovee engine mounts had actually worn through again. I am a little surprised,  after all the work we did making the mount square and running new bushes. Anyway that's now a thing of the past. We have some plans for the new mount so hopefully this will never occur again. 

The Donor Craft

Well this is where my engine is coming from. A plane wreak as such.

 It had a damaged wing from an accident and apparently they don't make the wings anymore. It got a bit hard so the insurance company sold it off ...and here I am now.

Like I mentioned before, I will miss the Aerovee, They have a distinct sound and I just like the way they run and feel when starting them and so on. It just feels like ..ahhhh, something everyone needs to experience!  When you're going flat out and honking it along they feel tough......

I will miss you Turbovee,  but perhaps I just was not patient enough to sort all the bugs out.

Well it's been an exciting time I guess.

It's been quite some time since I last posted I know but I have actually been doing a fair bit of flying lately. I have been doing a few Aero's here and there locally and have been formation flying with another club member also with his RV7.

I did have a big mishap in that time though which was a Rotec TBI failure in flight that almost had me making an emergency landing in a paddock! I was lucky is all I can say. Lucky that I had read a bit about what to do if they fail and also that I had an emergency fuel pump installed into the system in case of this exact situation. 
 I look back now on the event and can see the warning signs from that flight.  If I had paid better attention I would have turned back and also have saved my engine from major works required. I had been trialing Premium Unleaded and it also was a hot day. I had noticed from other test flights with Mogas that the Egt's tend to run a bit hotter and the engine actually runs a little leaner with the same settings just different fuel.  However I had also ignored the fact that, primarily over the last few flights, they had actually been starting to rise and I hadn't really noticed. It was a long term thing that, looking over the flight data from a few flights before, I now notice. The TBI was starting to block up and I was unaware.
So long story short I was travelling at about 2500ft on a very hot day, 2 x pob when the EGT's started to rise and of course along with the CHT's. As they passed 400f at full rich it also started to detonate badly. I switched the fuel pump on but no change. I started to then look for a paddock as it was only a matter of time I knew before the engine would quit. I pulled the fuel over ride and it started to just force feed it fuel at about 48 litres hour. It did run again, that was relieving, and I pulled basically full lean.  It was down to about 35 litres hour but running again and able to just climb. In that short time I was down to about 1000ft and was about to declare a mayday on the emergency channel but as it was now climbing again and I made a bee line for home.

We did make it back to base but the motor had roasted 2 x exhaust valves and 1 x rear cylinder was toast. We both had a beer on landing and thanked whoever that we made it home.

Anyway not to be too disheartened I grudgingly switched back to the Aerocarb after replacing two heads and the cylinder and was flying again in no time.

That was the day that I decided to go through the process of an Engine conversion.  I briefly considered a Jabiru 3300 but really, if I was honest with myself, I wanted a Rotax 912 through and through.

 I don't want anyone to think though that I didn't trust the Turbo Aerovee, really it's a testament as to how it held up yet still got me home after being absolutely roasted by the fuel issue from the Rotec Tbi. I saw temps of over 520f+ and it was still running strong. It was down badly on compression on 3 x cylinders as we limped home but with the turbo still going strong we barely noticed a power drop once I could get fuel back to the engine via the over rides.   

I think the decision was mostly made as I have just had a guts full of working on the engine. I have lost count of  how many engine mounts I had changed due to the mount being incorrectly made from factory. They are going okay now (the engine mounts) but I think the Tbi failing was the last straw.  

Since the engine rebuild I have done, at a guess, around 20 + hours. The last flight I had though was a ripper and couldn't have ended on a better high.  Our Aeroclub went out for a fly away lunch with 7x  planes and 14 x people. A great day was had by all and the Turbo Aerovee went like a song. I think I averaged about 130 kts each way as I was pushing it quite hard to try to beat some other planes that I got the jump on, although a Rv7 and a Cessna 400 beat me back, but hey, I gave it a try  :)  

I will miss the distinct sound the Aerovee makes and I think so will a few others in my Aeroclub. I feel the Turbo really makes them sing and I feel a bit disheartened I have given up just as I think I have gotten on top of it, but them the breaks.  Time for a new chapter.  

I finally have a Plane !!!!!!!!!!!!!!

Yes, As the title goes I am at that point now where I fully believe I have a reliable, functional, trustworthy and dead set awesome aircraft.

I have sort of slowly come to this conclusion over the last few weeks as I now have quite a few hours on the clock where I have done nothing more than put fuel in the plane and look at things. The cooling system is going better than I could have imagined and the 3d printed engine mounts are working so well I almost can't believe it. The plane is running like a Singer sewing machine so I have nothing at all to complain about. Go figure that from me.

I have been doing Aeros, Formation, Circuits, Nav's , Pfl's you name it and the plane has just been going great. I have been flight testing using blends of Avgas and Premium Unleaded 98 octane with results that are looking promising. In my last plane with the Aerovee I had major cooling issues and the Premium fuel was not really viable as the temps were a little higher. I am glad to say though with this engine and unleaded fuel the temps have so far shown no noticeable increase and the engine runs exactly the same as with straight avgas.

I'm really positive about how the plane is going now that I actually am starting to trust it a little. I'm not quite ready to go over tiger country just yet or down our coastal corridor but those days won't be far away at this rate. My next wish list is to carry out a dynamic prop balance to hopefully make it run that extra bit smooth. I will report how that goes when or if I can make that happen in the not too distant future.  

So signing off now with a big Double Thumbs Up.

 Sonex 1645 

VH-VWS

Engine mounts

So I got to that point once more where the prop flange was rubbing on the cowling again. This time though I was ready for it. 

 I had gone out on a limb following some info from the Sonex builders' site, bought a 3d printer, assembled it, went through hours of testing, learning and experimenting to a point where it would actually print stuff. Then came the next steep learning curve of making a good engine mount design in a 3d Cad software modelling program. Luckily I was aided in that little fast track education process by my 16 yr old daughter busting one out in about 10 mins on the computer with myself giving her the measurements via a set of verniers. 

Next challenge printing in flexible filament. Actually that part wasn't too bad really. Once the basics were sorted out with the printer in general the flexible filament part was manageable. I quickly learn't at certain  times, like temp changes or layer height speed changes, not to be too far away as usually only on those few moments during the 3x hour each print, the filament may jam. One needed to be ready just in case.   

I probably spent more hours learning how to get this all sorted than I care to actually recognize but it was definitely worth every second. 

So this was the cowling before I changed the mounts, I think I set an all time record for how long these ones lasted at about 8 x hours. I had done quite a few aeros and so on so that's probably why they were eaten out so quickly. Hopefully this will be the last time I post pics like this. 

So here are my newly fitted engine mounts and these pics were probably at about the 2 x hour mark. I have to admit the washers were not sized very well as i made the bushes 42mm over all up from the standard Sonex bushes at 32mm. I also made the smaller inner section 1 mm longer so they have a bit more squish factor where the accessory case sits on the bush. I have had the skeptics place their opinions and I have also had plenty of support for the choice I made in regard to using a 3d printed part on the plane. We will see how it turns out no doubt and I will report honestly either way how they go. 

I have to admit though I was really secretly chuffed about the colour choice I made for blue filament. I just think they look great. lol..... The red anodized material and the blue just do it for me :)