The Red Cube
 

Has anyone mounted the red cube to the top of the airfilter box? I'd like to run an insulated solid line from the cube into the Precision injector body with a 180 degree, 2 inch radius run.

I would advise against it, the top plate of the FAB is notorious for vibration cracks.

I suspect the added mass would not be healthy for the top plate, and the vibration would not be healthy for the red cube.

Thanks Mike, Looks like the firewall will be where it goes then. I was trying to reduce the length of hose and number of connections.
The plumbing is the most worrisome part of the build for me. Whith the fuel and exhaust so near each other and so many feet of fuel lines that are diffucult to support. I seem to do more contemplating than executing! Appreciate the input.

Hi Carl,

I agree with Mike that the top of the FAB is known to be a crack location (although many have gone to a simple brace attached to the carb bolt that seems to be helping a lot!), and I would be nervous about a rigid fuel line between two "masses" (even a light one like the cube) in an area with vibration.

If you're looking for simple and compact, I have had great luck so far in the -3 with the red cube on a bracket from the front sump bolts, and custom fuel lines to connect it up. The red cube is between the servo and spider, and is incredibly accurate.

Paul

Do you have a pic Paul?? Converting my 9a from carb to FI and I would like to put the cube between the servo and the spider.

Cheers,

db

Thanks Paul. If you are referencing the front bolts holding the sump to the engine, how did you route the fuel line around the exhaust? There's about 1-1/2" between the exhaust crossovers and the engine. Did you route it in front of the exhaust?

Here's a picture while things were still "under development" - it shows where the cube is mounted and the idea behind the fuel lines. this position was blessed by the makers of the Red Cube, who said they actually prefer solid mounting, and vibration was a problem with earlier cubes - but they fixed it with different bearings.





Unfortunately, this works really well on the RV-3 which has a four-pipe exhaust - I completely forgot that the cross-over is going to make it very tight - if not impossible. Oh well.....

Paul

Nice and clean. I was hoping to do something similar except I need to stay below the exhaust unless I can get real close (1/2") of the exhaust crossover; shielded of course.
Another question: Dan, you have the fuel entering on the front of the fuel injector unit. Mine enters on the right side (left in the photo). Can these be moved around?

I have a vertical fuel line off the back of the servo running behind the baffles up to the spider. The red cube is about half way up that vertical section, so has the preferred orientation. Still fine tuning the calibration on the D120 but seems good over the first 30hrs.
The cube is tie wrapped to surrounding lines so has a little flexibility but shouldn't pick up any vibration from the motor.

I had mine mounted in top of the air box but I moved it as I was not comfortable with the placement. It is still positioned between the servo and the spider but mounted to the case bolts. This is an old picture efor the fire-sleeve to short hose was added.

http://wcurtis.nerv10.com/90Electrical/EL2g.html