Those concerns were not warranted as it turned out that wit a slight modification of the routing of the right oil hose that attaches to the cooler, the system fit perfectly.
It first did not look so good though when I first tried to fit the cowl on. I installed the cooler guides on the bottom cowl as the first step.
In this picture you see the conventional routing of the right oil hose.
With a lot of pulling and cussing the cowl finally slipped into place (or better, yet, was forced to do so). That looked only good from the distance.
On the bottom curves though you could see that the cowl was under a lot of tension and pulled to the left (or pushed, as it later turned out).
So what was causing this? There is so little room in engine area that I could not take a picture of the interfere nor could I myself see it. Bending my arm in ludicrous ways to get my finger tips to follow the oil hoses and feeling for possible contacts, I finally found the reason. The fuel spillover line installed as a patch to the need of Rotax installing a different mechanical fuel pump that vents fuel overboard in case of a malfunction, prevented the oil line from moving up where the oil cooler wanted to go.
This might only be caused by me moving the oil cooler about 1.5" forward as I also had to move it slightly higher than initially planned for. But the clearance would be minimal (if any) in the original position as well.
The reason the oil line is interfering with the aluminum fuel vent line is that the oil line is pointing about 30 degrees toward outboards with the original routing and therefore crossing the vent line. I saw that if I could persuade the line to attach straight from the aft to the cooler, that the line would then clear the vent line and had a chance to bend out of the way further aft.
I tried a few approaches before I finally settled on this one:
The only problem I saw with this routing was that the lower water hose is pushed slightly towards the exhaust and could possibly touch the spring after a while. I planned to apply RTV between the spring and the hose in that area.
There is now only a minimal push to the left as you can see by the oil cooler mounting holes being just slightly out of position.
With this setup the cowling went on almost as easy as before without an oil cooler and there was practically no tension on the cowl.
Before taking the cowl off for the last touches on the lower engine installation, I thought I should take some more shots of this pile of aluminum that now looks almost like a plane...
My wife helped to get some shots of the interior with the cowl still on to give you an idea of how much clearance my modification gave me between oil cooler and muffler.
You'll be the judge as to how vital this modification has been. Without the distance I moved this forward, I could have just squeezed a finger between the cooler and the muffler.
Once the cowl was off again, I finished section 48 (Muffler Installation) by filling the springs with RTV. While at it, I also applied some extra RTV between one of the right springs and the water hose to prevent it from getting contact.
Now this had to cure and so I decided to go back inside and escape the 100 degF it had reached in the carport by then.
I cannot find the description for the next step but I know that the screws holding the bowl to the gascolator have to get safety wired. So I will do that next and then install the bottom cowl and leave it on.
The next section is the installation of the engine controls and after that I could install the tank and fire the thing up.
No comments:
Post a Comment